The Open Microbiology Journal




ISSN: 1874-2858 ― Volume 13, 2019
REVIEW ARTICLE

An Epidemiological Review on Emerging and Re-Emerging Parasitic Infectious Diseases in Malaysia



Saad M. Alasil1, *, Khairul A. Abdullah2
1 Department of Microbiology/Parasitology, Faculty of Medicine & Biomedical Sciences, MAHSA University, 42610 Jenjarom Selangor, Malaysia
2 Chancellery, MAHSA University, 42610 Jenjarom Selangor, Malaysia

Abstract

Emerging infectious diseases are infections that have recently appeared in a population over a defined period of time whereas, re-emerging infectious diseases are those that were once a health problem in a particular region or a country and are now emerging again. Parasitic infectious diseases represent a serious health problem in many developing countries and recently have started spreading to developed nations via international traveling or immigration. Malaysia is facing many challenges caused by various parasitic pathogens. The lack of awareness among disadvantaged populations such as the Orang Asli community and the dependency on foreign workers has led to an influx of immigrants to Malaysia from countries endemic to various parasitic diseases. Understanding the social and economic dynamics of such diseases can help anticipate and subsequently control their emergence. Raising public awareness, developing robust public health infrastructure and implementing point-of-care diagnostics will help curb the spread of such diseases. This review provides epidemiological insights into the reported emerging and re-emerging parasitic infectious diseases in Malaysia over the past two decades.

Keywords: Emerging, Re-emerging, Parasitic, Infectious diseases, Malaysia, Zoonotic, Orang asli.


Article Information


Identifiers and Pagination:

Year: 2019
Volume: 13
First Page: 112
Last Page: 120
Publisher Id: TOMICROJ-13-112
DOI: 10.2174/1874285801913010112

Article History:

Received Date: 30/12/2018
Revision Received Date: 28/03/2019
Acceptance Date: 01/04/2019
Electronic publication date: 31/05/2019
Collection year: 2019

Article Metrics:

CrossRef Citations:
0

Total Statistics:

Full-Text HTML Views: 473
Abstract HTML Views: 282
PDF Downloads: 98
ePub Downloads: 84
Total Views/Downloads: 937

Unique Statistics:

Full-Text HTML Views: 236
Abstract HTML Views: 188
PDF Downloads: 70
ePub Downloads: 59
Total Views/Downloads: 553
Geographical View

© 2019 Alasil and Abdullah.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


* Address correspondence to this author at the Department of Microbiology/ Parasitology, Faculty of Medicine & Biomedical Sciences, MAHSA University, Level 7, Main Building, Bandar Saujana Putra, 42610 Jenjarom, Selangor. Malaysia; Tel: +60126272574; Email saadalasil@mahsa.edu.my




1. INTRODUCTION

Emerging infectious diseases are infections that have recently appeared in a population over a defined period of time whereas re-emerging infectious diseases are those that were once a health problem in a particular region or a country and now are emerging again [1Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis 1995; 1(1): 7-15.[http://dx.doi.org/10.3201/eid0101.950102] [PMID: 8903148] ]. The World Health Organization (WHO) defines zoonoses infections transmitted from animals to humans with wild animals as the source of most emerging infections [2Kuiken T, Leighton FA, Fouchier RA, et al. Public health. Pathogen surveillance in animals. Science 2005; 309(5741): 1680-1.[http://dx.doi.org/10.1126/science.1113310] [PMID: 16150997] ]. Countries in Southeast Asia have witnessed an increase in the incidence of some parasitic infectious diseases in recent decades [3Weiss RA, McMichael AJ. Social and environmental risk factors in the emergence of infectious diseases. Nat Med 2004; 10(12): S70-6.[http://dx.doi.org/10.1038/nm1150] [PMID: 15577934] ]. Malaysia is facing many challenges caused by various parasitic pathogens. The lack of awareness among disadvantaged populations such as the Orang Asli (i.e. indigenous people of Peninsular Malaysia) and the dependency on foreign workers have led to an influx of immigrants to Malaysia from countries endemic to various parasitic diseases [4Kit LS. Emerging and re-emerging diseases in Malaysia. Asia Pac J Public Health 2002; 14(1): 6-8.[http://dx.doi.org/10.1177/101053950201400103] [PMID: 12597511] ]. Moreover, the constant disturbance of natural habitats by humans have led to a loss of biodiversity which has led to an increase in the prevalence of infectious diseases [5Johnson PT, Thieltges DW. Diversity, decoys and the dilution effect: How ecological communities affect disease risk. J Exp Biol 2010; 213(6): 961-70.[http://dx.doi.org/10.1242/jeb.037721] [PMID: 20190121] ]. Furthermore, foodborne and waterborne diseases such as, intestinal protozoan infections that are associated with poor hygiene, are still a health problem in Malaysia, particularly among rural communities. Understanding the dynamics of parasitic infections can help anticipate and subsequently control their emergence and re-emergence. There is no readily available vaccine for most parasitic infections, therefore, developing robust healthcare infrastructure, implementing point-of-care diagnostics as well as raising awareness on hygienic practices are essential tools to curb the spread of such infections [3Weiss RA, McMichael AJ. Social and environmental risk factors in the emergence of infectious diseases. Nat Med 2004; 10(12): S70-6.[http://dx.doi.org/10.1038/nm1150] [PMID: 15577934] ]. This review provides epidemiological insights into the reported emerging and re-emerging parasitic infectious diseases in Malaysia over the past two decades.

2. EMERGING AND RE-EMERGING PARASITIC INFECTIOUS DISEASES

Parasitic diseases are generally grouped into human and animal diseases. However, zoonotic infections fall into both categories as they can infect humans as well as animals [6Atehmengo NL, Nnagbo CS. Emerging animal parasitic diseases: A global overview and appropriate strategies for their monitoring and surveillance in Nigeria. Open Microbiol J 2014; 8: 87-94.[http://dx.doi.org/10.2174/1874285801408010087] [PMID: 25328553] ]. The following are some of the important parasitic infectious diseases that have been emerging and/or re-emerging in Malaysia arranged in alphabetical order:

2.1. Amoebiasis

Amoebiasis is an emerging parasitic infectious disease with significant morbidity and mortality, particularly in poor tropical regions. Infection is acquired by ingesting food and/or water contaminated with the parasite Entamoeba histolytica [7Stanley SL Jr. Amoebiasis. Lancet 2003; 361(9362): 1025-34.[http://dx.doi.org/10.1016/S0140-6736(03)12830-9] [PMID: 12660 071] ]. A large number of hospital-based studies in Malaysia has been carried out with the aim to determine the prevalence of amoebiasis [8Goh KL, Wong NW, Paramsothy M, Nojeg M, Somasundaram K. Liver abscess in the tropics: Experience in the University Hospital, Kuala Lumpur. Postgrad Med J 1987; 63(741): 551-4.[http://dx.doi.org/10.1136/pgmj.63.741.551] [PMID: 3658864] ]. A study was conducted from 2005 to 2006 with the aim to determine the prevalence of gastrointestinal protozoan parasites in Kota Kinabalu, Sabah. It was concluded the parasitic load of Entamoeba histolytica was the highest and that the school environment was the potential medium to spread infections. In a study conducted to detect the true prevalence of E. histolytica, E. dispar and E. moshkovskii infections among Orang Asli tribes in western Malaysia [9Anuar TS, A MH, Abdul Ghani MK, et al. Molecular epidemiology of amoebiasis in Malaysia: highlighting the different risk factors of Entamoeba histolytica and Entamoeba dispar infections among Orang Asli communities. Int J Parasitol 2012; 42: 13-4.[http://dx.doi.org/10.1016/j.ijpara.2012.10.003] ], the results showed that most individuals were infected with E. dispar (13.4%), followed by E. histolytica (3.2%) and E. moshkovskii (1.0%) with a low prevalence of mixed infections [9Anuar TS, A MH, Abdul Ghani MK, et al. Molecular epidemiology of amoebiasis in Malaysia: highlighting the different risk factors of Entamoeba histolytica and Entamoeba dispar infections among Orang Asli communities. Int J Parasitol 2012; 42: 13-4.[http://dx.doi.org/10.1016/j.ijpara.2012.10.003] ]. This has provided new insight into the distribution of amoebiasis among these underprivileged communities. A cross-sectional study was conducted in 2014 to investigate the intestinal risk factors of polyparasitism among school children in Pahang (the third largest Malaysian state by area) [10Al-Delaimy AK, Al-Mekhlafi HM, Nasr NA, et al. Epidemiology of intestinal polyparasitism among Orang Asli school children in rural Malaysia. PLoS Negl Trop Dis 2014; 8(8): e3074.[http://dx.doi.org/10.1371/journal.pntd.0003074] [PMID: 25144662] ]. Their results showed that Entamoeba spp. infections had a low prevalence compared to infections with other parasites such as Trichuris spp. and Ascaris spp. [10Al-Delaimy AK, Al-Mekhlafi HM, Nasr NA, et al. Epidemiology of intestinal polyparasitism among Orang Asli school children in rural Malaysia. PLoS Negl Trop Dis 2014; 8(8): e3074.[http://dx.doi.org/10.1371/journal.pntd.0003074] [PMID: 25144662] ]. Although amoebiasis is mainly encountered in poor rural areas in Malaysia, it has the potential to be transmitted and thus emerges among urban populations. In developed countries, amebiasis is slowly emerging among returning travelers and men who have sex with men (MSM) [11Shirley DT, Farr L, Watanabe K, Moonah S. A review of the global burden, new diagnostics, and current therapeutics for amebiasis. Open Forum Infect Dis 2018; 5(7): ofy161.[http://dx.doi.org/10.1093/ofid/ofy161] [PMID: 30046644] ]. Although molecular-based diagnostic methods such as the Polymerase Chain Reaction (PCR) are readily available, they remain underutilized aiding in the misdiagnosis of this infection [11Shirley DT, Farr L, Watanabe K, Moonah S. A review of the global burden, new diagnostics, and current therapeutics for amebiasis. Open Forum Infect Dis 2018; 5(7): ofy161.[http://dx.doi.org/10.1093/ofid/ofy161] [PMID: 30046644] ]. There is no available vaccine against any Entamoeba spp. infection yet, therefore, establishing robust healthcare infrastructure particularly in remote villages, implementing point of care diagnostics as well as raising awareness on the importance of hygienic practices are essential tools to curb the spread of amoebiasis.

2.2. Ascariasis

Ascariasis is a re-emerging infectious disease caused by an infection with the large roundworm, Soil-Transmitted Helminth (STH) Ascaris lumbricoides [12Gabrielli A-F, Montresor A, Chitsulo L, Engels D, Savioli L. Preventive chemotherapy in human helminthiasis: Theoretical and operational aspects. Trans R Soc Trop Med Hyg 2011; 105(12): 683-93.[http://dx.doi.org/10.1016/j.trstmh.2011.08.013] [PMID: 22040463] ]. It is one of the most common infections affecting travelers and is grouped under neglected Intestinal Parasitic Infections (IPIs). Southeast Asia accounts for a large number of Ascaris cases with 126 million infected individuals [13Pullan RL, Smith JL, Jasrasaria R, Brooker SJ. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010. Parasit Vectors 2014; 7(1): 37.[http://dx.doi.org/10.1186/1756-3305-7-37] [PMID: 24447578] ]. Malaysia has not been spared from the burden of Ascariasis particularly among poor communities such as the Orang Asil. In 1988, the status of helminth infections among children living in the slum areas of Kuala Lumpur was assessed with 50% of these infections due to Ascaris lumbricoides [14Bundy DA, Kan SP, Rose R. Age-related prevalence, intensity and frequency distribution of gastrointestinal helminth infection in urban slum children from Kuala Lumpur, Malaysia. Trans R Soc Trop Med Hyg 1988; 82(2): 289-94.[http://dx.doi.org/10.1016/0035-9203(88)90450-6] [PMID: 3188158] ]. This indicated that the frequency of Ascaris lumbricoides infections were age-dependent suggesting lower incidences in infants than in older children [14Bundy DA, Kan SP, Rose R. Age-related prevalence, intensity and frequency distribution of gastrointestinal helminth infection in urban slum children from Kuala Lumpur, Malaysia. Trans R Soc Trop Med Hyg 1988; 82(2): 289-94.[http://dx.doi.org/10.1016/0035-9203(88)90450-6] [PMID: 3188158] ].

The prevalence of parasitic infections among aboriginal children in the state of Kelantan was assessed in 1996 with Ascaris lumbricoides being detected in 79.8% of stool samples. In 2003, a study was conducted to determine the prevalence of parasitic infections caused by Entamoeba histolytica, Ent-amoeha coli, Giardia lamblia, Ascaris lumbricoides, and Trichuris trichiura among schoolchildren living in the Crocker Range Park (CRP) of the state of Sabah [15Nor Aza SAaJA. Parasitic infections in human communities living on the fringes of the crocker range park Sabah, Malaysia ASEAN Review of Biodiversity and Environmental Conservation (ARBEC) 2003.]. Results showed that Trichuris trichiura infection was the highest (10.0%) compared to Ascaris (8.7%) and hookworm (3.3%) with a 12.6% prevalence for a single infection, 4.6% of double infection and 2.0% of triple infection [15Nor Aza SAaJA. Parasitic infections in human communities living on the fringes of the crocker range park Sabah, Malaysia ASEAN Review of Biodiversity and Environmental Conservation (ARBEC) 2003.]. In 2016, a cross-sectional study was conducted on 388 migrant workers in Malaysia from various working sectors to detect the prevalence of intestinal parasitic infections [16Sahimin N, L.Y.A.L. , Ariffin F, Behnke JM, Lewis JW, Mohd Zain SN. Migrant workers in Malaysia: Current implications of sociodemographic and environmental characteristics in the transmission of intestinal parasitic infections. PLoS Negl Trop Dis 2016; 1-17.]. Results showed that Ascaris lumbricoides occurred in 72.8% of the Nepalese workers and 68.1% on the Indian workers. This indicated that environmental and socio-demographic factors played a major role and that workers who stayed in Malaysia for less than a year were most likely to show high levels of infection [16Sahimin N, L.Y.A.L. , Ariffin F, Behnke JM, Lewis JW, Mohd Zain SN. Migrant workers in Malaysia: Current implications of sociodemographic and environmental characteristics in the transmission of intestinal parasitic infections. PLoS Negl Trop Dis 2016; 1-17.]. A year later in 2017, a study reported that 62.9% of migrant workers were positive for at least one intestinal parasite within one year of their arrival in Malaysia with A. lumbricoides being the highest (43.3%) in prevalence [17 F.F., L., Stop the bugs at the gate in The Star Online 2017: Malaysia]. Routine mass-drug administration on newly arriving foreign workers and health education programmes on the importance of personal hygiene and sanitation are needed in order to minimize the incidence of ascariasis and prevent its re-emergence. As the number of immigrant workers in Malaysia has drastically increased over the last decade, there is an urgent need for reliable epidemiological data of parasitic infectious diseases. Moreover, ascariasis along with other STHs is transmitted via the fecal-oral route as a result of poor sanitary practices. Therefore, detecting the prevalence, identifying risk factors and raising awareness are key elements to curb the spread of this disease.

2.3. Blastocystis

Blastocystis is an emerging zoonotic disease caused by the intestinal protozoan Blastocytis hominis. Poor hygiene and sanitation are major risk factors for its spread. It affected mostly children, animal handlers, travelers, immigrants as well as soldiers posted in endemic countries [18Prasad K.J. Emerging and re-emerging parasitic diseases JIMSA 2010; 23(1): 46.]. Blastocystis is not yet endemic in Malaysia, however, there are sporadic high numbers of cases reported and with the heavy influx of immigrants from neighboring countries, this can lead it to become endemic. The recent increase in the number of reported blastocystis cases can be attributed to the advancement in diagnostic methods [19Zarlenga DS, Trout JM. Concentrating, purifying and detecting waterborne parasites. Vet Parasitol 2004; 126(1-2): 195-217.[http://dx.doi.org/10.1016/j.vetpar.2004.09.001] [PMID: 15567585] ]. In 2004, a cross-sectional survey among three Orang Asli tribes provided important epidemiological data of Blastocystis infection revealing that untreated drinking water was the main source of blastocystis transmission which raised the need for an intervention strategy to practice good water treatment in order to reduce the incidence of blastocystis [20Anuar TS, Ghani MK, Azreen SN, Salleh FM, Moktar N. Blastocystis infection in Malaysia: Evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli. Parasit Vectors 2013; 6: 40.[http://dx.doi.org/10.1186/1756-3305-6-40] [PMID: 23433099] ]. In 2011, blastocystis was reported in the water of two rivers located in recreational areas in Malaysia. Such detection indicated that the causal parasite Blastocystis hominis has the potential to be easily transmitted to humans [21Ithoi I. Occurrence of blastocystis in water of two rivers from recreational areas in malaysia J Parasitol Res, 2011 2011.]. In 2012, the prevalence of blastocystis among school children living in rural areas of the state of Pahang was assessed [22Abdulsalam AM, Ithoi I, Al-Mekhlafi HM, Ahmed A, Surin J, Mak JW. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren. Parasitology 2012; 139(8): 1014-20.[http://dx.doi.org/10.1017/S0031182012000340] [PMID: 22444778] ]. Their results showed that blastocystis was high among children and that infected drinking water was the main source of infection which required raising awareness among the affected children as well as their parents [22Abdulsalam AM, Ithoi I, Al-Mekhlafi HM, Ahmed A, Surin J, Mak JW. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren. Parasitology 2012; 139(8): 1014-20.[http://dx.doi.org/10.1017/S0031182012000340] [PMID: 22444778] ]. Zoonotic transmission of Blastocystis sp. from livestock was investigated in different Malaysian farms and results showed that the proximity to human dwellings accounted for the multiple infections [23Tan TC, Tan PC, Sharma R, Sugnaseelan S, Suresh KG. Genetic diversity of caprine blastocystis from peninsular malaysia. Parasitol Res 2013; 112(1): 85-9.[http://dx.doi.org/10.1007/s00436-012-3107-3] [PMID: 22961236] ]. In 2016, a cross-sectional study was carried out to investigate the incidence of intestinal parasitic infections among children from five states in Peninsular Malaysia [24Nithyamathi K, Chandramathi S, Kumar S. Predominance of Blastocystis sp. infection among school children in Peninsular Malaysia. PLoS One 2016; 11(2): e0136709.[http://dx.doi.org/10.1371/journal.pone.0136709] [PMID: 26914483] ]. Their results showed that the blastocystis was the most prevalent with 10.6% which was attributed to the lack of education among these rural communities [24Nithyamathi K, Chandramathi S, Kumar S. Predominance of Blastocystis sp. infection among school children in Peninsular Malaysia. PLoS One 2016; 11(2): e0136709.[http://dx.doi.org/10.1371/journal.pone.0136709] [PMID: 26914483] ]. It is worth mentioning that blastocystis cysts are resistant to chlorination which allows them to persist for longer times in the environment [25Zaki M, Zaman V, Sheikh NA. Resistance of blastocystis hominis cysts to chlorine. J Pak Med Assoc 1996; 46(8): 178-9.[PMID: 8936976] ]. Moreover, the ingestion of only a few cysts is enough to cause infection [26Yoshikawa H, Yoshida K, Nakajima A, Yamanari K, Iwatani S, Kimata I. Fecal-oral transmission of the cyst form of Blastocystis hominis in rats. Parasitol Res 2004; 94(6): 391-6.[http://dx.doi.org/10.1007/s00436-004-1230-5] [PMID: 15480786] ]. Therefore, local authorities must implement strategies that provide better health facilities related to water treatment to avoid the emergence of blastocystis in Malaysia.

2.4. Cryptosporidiosis

Cryptosporidiosis is an emerging zoonotic parasitic disease that spreads via contaminated food and water and is caused by the enteric parasite Cryptosporidium parvum. Infection is acquired by ingesting water or food contaminated with the oocysts of Cryptosporidium species which in some cases can be fatal [27Hoerr FJ, Current WL, Haynes TB. Fatal cryptosporidiosis in quail. Avian Dis 1986; 30(2): 421-5.[http://dx.doi.org/10.2307/1590550] [PMID: 3729889] ]. In 2007, a study was conducted to re-evaluate the occurrence of Cryptosporidium species in the fecal samples of birds in the national Malaysian (Zoo Negara) [28Lim Yal RM, Shukri MM. Cryptosporidiosis among birds and bird handlers at Zoo Negara, Malaysia. Southeast Asian J Trop Med Public Health 2007; 38: 19-26.]. Based on their results, an association of cryptosporidiosis among the affected birds and their handlers was established indicating a zoonotic transmission [28Lim Yal RM, Shukri MM. Cryptosporidiosis among birds and bird handlers at Zoo Negara, Malaysia. Southeast Asian J Trop Med Public Health 2007; 38: 19-26.]. In 2007, a cross-sectional study was conducted among Orang Asli communities in the state of Pahang to investigate the distribution of both Cryptosporidium and Giardia species [29Mahdy MAK. S.J., Al-Mekhlafi H.M., Current situation of Giardia and Cryptosporidium among Orang Asli (aboriginal) communities in Pahang, Malaysia. Southeast Asian J Trop Med Public Health 2007; 38: 27-31.]. Results showed that cryptosporidiosis had a prevalence of 4.1% with no gender bias between Cryptosporidium and Giardia spp. indicating that such diseases remain significant health problems among the Orang Asli in Malaysia [29Mahdy MAK. S.J., Al-Mekhlafi H.M., Current situation of Giardia and Cryptosporidium among Orang Asli (aboriginal) communities in Pahang, Malaysia. Southeast Asian J Trop Med Public Health 2007; 38: 27-31.]. In 2012, a study was conducted to detect the prevalence of cryptosporidiosis in 130 diarrheal stool samples of children at two urban hospitals in the state Selangor [30Rossle NF. L.B., Malik A.S., Fadzli F.M., Abu N.A., Cryptosporidiosis among children with diarrhea admitted to Hospital Selayang and Hospital Sungai Buloh, Selangor, Malaysia. J Trop Med Parasitol 2012; 35(2): 55-62.]. Their results indicated that 4.62% of samples were positive for Cryptosporidium spp. indicating that hygiene standards should be improved and monitored in daycare centers where many parents leave their children for long hours [30Rossle NF. L.B., Malik A.S., Fadzli F.M., Abu N.A., Cryptosporidiosis among children with diarrhea admitted to Hospital Selayang and Hospital Sungai Buloh, Selangor, Malaysia. J Trop Med Parasitol 2012; 35(2): 55-62.]. In 2017, a cross-sectional study was conducted on 388 migrant workers in Peninsular Malaysia to determine the status of protozoan infections [31Mohd Zain SN. Giardia duodenalis and Cryptosporidium parvum infection status among migrant workers in Peninsular Malaysia in British Society for Parasitology 2017.]. Microscopy examination showed 42 (10.8%) positive with Giardia spp. and 12 (3.1%) samples with Cryptosporidium spp. which highlighted the potential risks of waterborne as well as foodborne infections in the spread of such infections [31Mohd Zain SN. Giardia duodenalis and Cryptosporidium parvum infection status among migrant workers in Peninsular Malaysia in British Society for Parasitology 2017.]. Cryptosporidiosis has the potential to spread and emerge as a significant health problem in many rural areas across Malaysia. It can become life-threatening particularly among the elderly, small children and AIDS patient. Therefore, regular monitoring of water and food sources using investigational methods such as Microbial Source Tracking (MST) can distinguish between the human and animal sources of fecal contamination hence preventing its emergence [32Shrivastava AK, Kumar S, Smith WA, Sahu PS. Revisiting the global problem of cryptosporidiosis and recommendations. Trop Parasitol 2017; 7(1): 8-17.[PMID: 28459010] ].

2.5. Filariasis

Lymphatic Filariasis (LF), also known as Elephantiasis, is a re-emerging parasitic infectious disease caused by the nematode worms Wuchereria bancrofti, Brugia malayi and Brugia timori that are transmitted to humans by the bite of infected Anopheles, Culex and Aedes mosquitoes. Brugia malayi is the main parasitic species that causes LF in Malaysia [33Kwa B. Environmental change, development and vectorborne disease: Malaysia’s experience with filariasis, scrub typhus and dengue. Environ Dev Sustain 2008; 10(2): 209-17.[http://dx.doi.org/10.1007/s10668-006-9060-5] ]. Between 2003 and 2006, five patients with clinical manifestations of LF were referred to the University Malaya Medical Centre [34Tan LH, Fong MY, Mahmud R, Muslim A, Lau YL, Kamarulzaman A. Zoonotic Brugia pahangi filariasis in a suburbia of Kuala Lumpur City, Malaysia. Parasitol Int 2011; 60(1): 111-3.[http://dx.doi.org/10.1016/j.parint.2010.09.010] [PMID: 20951228] ]. Results showed that two of the patients tested positive with an unknown animal filarial worm named Brugia pahangi [34Tan LH, Fong MY, Mahmud R, Muslim A, Lau YL, Kamarulzaman A. Zoonotic Brugia pahangi filariasis in a suburbia of Kuala Lumpur City, Malaysia. Parasitol Int 2011; 60(1): 111-3.[http://dx.doi.org/10.1016/j.parint.2010.09.010] [PMID: 20951228] ]. It was later reported that domestic cats in the suburbia, where all patients came being tested positive for Wuchereria bancrofti microfilaria (mf) even though there was no recorded history of Brugia malayi infection in the area, can be the source of zoonotic infection. Despite the fact that Mass Drug Administration (MDA) programmes have been successfully executed in Malaysia as part of the Global Program to Eliminate Lymphatic Filariasis (GPELF) by the year 2020 [35Rahmah N, Lim BH, Azian H, Ramelah TS, Rohana AR. Short communication: Use of a recombinant antigen-based ELISA to determine prevalence of brugian filariasis among Malaysian schoolchildren near Pasir Mas, Kelantan-Thailand border. Trop Med Int Health 2003; 8(2): 158-63.[http://dx.doi.org/10.1046/j.1365-3156.2003.01004.x] [PMID: 12581 442] ], Malaysia continues to face challenges of acquiring the disease due to the arrival of immigrant workers as well as the vector’s natural presence [36Jureen J-MCaR. imported asymptomatic bancroftian filariasis discovered from a Plasmodium vivax Infected Patient: A case report from Singapore Case reports in infectious diseases 2017.]. In 2017, Wuchereria bancrofti infections were reported among foreign immigrants coming to Malaysia [17 F.F., L., Stop the bugs at the gate in The Star Online 2017: Malaysia] outnumbering Brugia malayi infections [23Tan TC, Tan PC, Sharma R, Sugnaseelan S, Suresh KG. Genetic diversity of caprine blastocystis from peninsular malaysia. Parasitol Res 2013; 112(1): 85-9.[http://dx.doi.org/10.1007/s00436-012-3107-3] [PMID: 22961236] ]. The recent influx of foreign workers from LF endemic countries is a matter of concern in Malaysia as it can lead to its re-emergence [37Rahmah N, Anuar AK, Ariff RH, et al. Use of antifilarial IgG4-ELISA to detect Brugia malayi infection in an endemic area of Malaysia. Trop Med Int Health 1998; 3(3): 184-8.[http://dx.doi.org/10.1046/j.1365-3156.1998.00229.x] [PMID: 9593 356] ]. Moreover, the unavailability of reliable diagnostic tests is another obstacle in the implementation of elimination programmes in areas where brugian filariasis is endemic. Regions that used the Brugia Rapid (BR) diagnostic test, developed earlier in Malaysia to detect IgG4 antibodies, recorded a sharp fall in mf positive rates [38Supali T, Rahmah N, Djuardi Y, Sartono E, Rückert P, Fischer P. Detection of filaria-specific IgG4 antibodies using Brugia Rapid test in individuals from an area highly endemic for Brugia timori. Acta Trop 2004; 90(3): 255-61.[http://dx.doi.org/10.1016/j.actatropica.2004.02.001] [PMID: 15099 812] ]. BR would be very useful as a diagnostic tool to aid in the mapping and certification phases of the filariasis elimination programme in brugian filariasis endemic areas [39Jamail M, Andrew K, Junaidi D, Krishnan AK, Faizal M, Rahmah N. Field validation of sensitivity and specificity of rapid test for detection of Brugia malayi infection. Trop Med Int Health 2005; 10(1): 99-104.[http://dx.doi.org/10.1111/j.1365-3156.2004.01334.x] [PMID: 15655 019] ].

Although Malaysia is considered endemic for LF, the disease is generally controlled as a result of the successful MDA program. However, LF has the potential to re-emerge mainly due to its easy mode of transmission through blood-sucking mosquitoes as well as the presence of a large number of immigrant workers in Malaysia arriving mostly from LF endemic countries. The ministry of health, as well as other organizations, must play a role in raising public awareness to improve knowledge of the diseases and increase the chances to take part in the MDA program.

2.6. Giardiasis

Giardiasis is an emerging parasitic infectious disease that represents a significant public health burden causing diarrhoeal diseases particularly in tropical countries [40Al-Mekhlafi HM, Al-Maktari MT, Jani R, et al. Burden of Giardia duodenalis infection and its adverse effects on growth of school children in rural Malaysia. PLoS Negl Trop Dis 2013; 7(10): e2516.[http://dx.doi.org/10.1371/journal.pntd.0002516] [PMID: 24205426] ]. Despite great advances in the socioeconomic status of Malaysia, intestinal parasitic infections coupled with malnutrition are still a problem mainly among Orang Asli children in poor rural areas [41Al-Mekhlafi HM, Surin J, Sallam AA, Abdullah AW, Mahdy MA. Giardiasis and poor vitamin A status among aboriginal school children in rural Malaysia. Am J Trop Med Hyg 2010; 83(3): 523-7.[http://dx.doi.org/10.4269/ajtmh.2010.09-0371] [PMID: 20810815] ]. In 1998, a study was conducted to investigate the prevalence and risk factors of Giardia duodenalis infection among 917 individuals aged between 2-70 years old in Malaysian rural communities [42Norhayati M, Penggabean M, Oothuman P, Fatmah MS. Prevalence and some risk factors of Giardia duodenalis infection in a rural community in Malaysia. Southeast Asian J Trop Med Public Health 1998; 29(4): 735-8.[PMID: 10772555] ]. Their results showed that 19.2% of individuals were infected with G. duodenalis and that person-to-person contact was the main mode of transmission [42Norhayati M, Penggabean M, Oothuman P, Fatmah MS. Prevalence and some risk factors of Giardia duodenalis infection in a rural community in Malaysia. Southeast Asian J Trop Med Public Health 1998; 29(4): 735-8.[PMID: 10772555] ]. Good hygiene, as well as awareness, can control Giardiasis among such communities. In 2005, a cross-sectional study investigated Giardiasis as a predictor of childhood malnutrition among Orang Asli children in the state of Selangor [43Al-Mekhlafi MS, Azlin M, Nor Aini U, et al. Giardiasis as a predictor of childhood malnutrition in Orang Asli children in Malaysia. Trans R Soc Trop Med Hyg 2005; 99(9): 686-91.[http://dx.doi.org/10.1016/j.trstmh.2005.02.006] [PMID: 15992838] ]. Results showed that Giardia duodenalis was detected in 24.9% of children indicating that Giardiasis was indeed considered as a predictor of malnutrition among such population [43Al-Mekhlafi MS, Azlin M, Nor Aini U, et al. Giardiasis as a predictor of childhood malnutrition in Orang Asli children in Malaysia. Trans R Soc Trop Med Hyg 2005; 99(9): 686-91.[http://dx.doi.org/10.1016/j.trstmh.2005.02.006] [PMID: 15992838] ]. In 2011, the distribution of waterborne parasites was investigated in both Peninsular Malaysia and the southeastern coast of Thailand [44Kumar T, Onichandran S, Lim YA, et al. Comparative study on waterborne parasites between Malaysia and Thailand: A new insight. Am J Trop Med Hyg 2014; 90(4): 682-9.[http://dx.doi.org/10.4269/ajtmh.13-0266] [PMID: 24567315] ]. Results showed that the water was more contaminated with Giardia cysts and Cryptosporidium oocysts compared to those in Thailand [44Kumar T, Onichandran S, Lim YA, et al. Comparative study on waterborne parasites between Malaysia and Thailand: A new insight. Am J Trop Med Hyg 2014; 90(4): 682-9.[http://dx.doi.org/10.4269/ajtmh.13-0266] [PMID: 24567315] ]. It has been reported that Malaysian waters and soil are generally contaminated enough to act as vehicles to transmit Giardiasis [45Lim YA, Ahmad RA, Smith HV. Current status and future trends in Cryptosporidium and Giardia epidemiology in Malaysia. J Water Health 2008; 6(2): 239-54.[http://dx.doi.org/10.2166/wh.2008.023] [PMID: 18209286] ]. Giardia spp. is considered an opportunistic pathogen among HIV/AIDS patients. Therefore, investigating its prevalence and epidemiology can help to curb its emergence practically in the midst of a rise in HIV cases in Malaysia [46Lim YA, Iqbal A, Surin J, et al. First genetic classification of Cryptosporidium and Giardia from HIV/AIDS patients in Malaysia. Infect Genet Evol 2011; 11(5): 968-74.[http://dx.doi.org/10.1016/j.meegid.2011.03.007] [PMID: 21439404] ]. In 2011, a study was conducted to examine stools specimens from 122 patients with HIV/AIDS. Results revealed that the zoonotically important Giardia duodenalis was the identified species [46Lim YA, Iqbal A, Surin J, et al. First genetic classification of Cryptosporidium and Giardia from HIV/AIDS patients in Malaysia. Infect Genet Evol 2011; 11(5): 968-74.[http://dx.doi.org/10.1016/j.meegid.2011.03.007] [PMID: 21439404] ]. More studies are needed to analyze this pathogen not only in humans but also in domestic and wild animals in Malaysia [46Lim YA, Iqbal A, Surin J, et al. First genetic classification of Cryptosporidium and Giardia from HIV/AIDS patients in Malaysia. Infect Genet Evol 2011; 11(5): 968-74.[http://dx.doi.org/10.1016/j.meegid.2011.03.007] [PMID: 21439404] ]. In 2012, a study on Giardiasis among Malaysian Orang Asli tribes have identified Giardia intestinalis as a risk factor [47Anuar TS, Al-Mekhlafi HM, Ghani MK, et al. Giardiasis among different tribes of Orang Asli in Malaysia: Highlighting the presence of other family members infected with Giardia intestinalis as a main risk factor. Int J Parasitol 2012; 42(9): 871-80.[http://dx.doi.org/10.1016/j.ijpara.2012.07.003] [PMID: 22846786] ]. Screening and treating of affected individuals can help health authorities to combat such infection particularly among Orang Asli communities [47Anuar TS, Al-Mekhlafi HM, Ghani MK, et al. Giardiasis among different tribes of Orang Asli in Malaysia: Highlighting the presence of other family members infected with Giardia intestinalis as a main risk factor. Int J Parasitol 2012; 42(9): 871-80.[http://dx.doi.org/10.1016/j.ijpara.2012.07.003] [PMID: 22846786] ]. In 2013, aboriginal children in some Malaysian rural areas were the subject to investigate the burden of Giardia duodenalis infection [40Al-Mekhlafi HM, Al-Maktari MT, Jani R, et al. Burden of Giardia duodenalis infection and its adverse effects on growth of school children in rural Malaysia. PLoS Negl Trop Dis 2013; 7(10): e2516.[http://dx.doi.org/10.1371/journal.pntd.0002516] [PMID: 24205426] ]. Results showed that there was a strong association between such infection and the weight of affected children indicating that more efforts from the local health authorities are required to identify and implement control measures among communities [40Al-Mekhlafi HM, Al-Maktari MT, Jani R, et al. Burden of Giardia duodenalis infection and its adverse effects on growth of school children in rural Malaysia. PLoS Negl Trop Dis 2013; 7(10): e2516.[http://dx.doi.org/10.1371/journal.pntd.0002516] [PMID: 24205426] ]. The first study in Malaysia to molecularly characterize Giardia duodenalis infection in 310 goat fecal specimens was conducted in 2013 [48Lim YA, Mahdy MA, Tan TK, et al. First molecular characterization of Giardia duodenalis from goats in Malaysia. Mol Cell Probes 2013; 27(1): 28-31.[http://dx.doi.org/10.1016/j.mcp.2012.08.006] [PMID: 22971518] ]. Their results revealed that detecting the ‘zoonotic’ assemblages A and B indicates that these infected goats can act as potential reservoirs for human Giardiasis [48Lim YA, Mahdy MA, Tan TK, et al. First molecular characterization of Giardia duodenalis from goats in Malaysia. Mol Cell Probes 2013; 27(1): 28-31.[http://dx.doi.org/10.1016/j.mcp.2012.08.006] [PMID: 22971518] ]. In order to prevent the emergence of Giardiasis in Malaysia, a multidisciplinary approach is required to determine the level of water contamination with Giardia, Cryptosporidium and other zoonotic parasites [45Lim YA, Ahmad RA, Smith HV. Current status and future trends in Cryptosporidium and Giardia epidemiology in Malaysia. J Water Health 2008; 6(2): 239-54.[http://dx.doi.org/10.2166/wh.2008.023] [PMID: 18209286] ].

2.7. Malaria

Malaria is the most important emerging parasitic disease worldwide. It is caused by the Plasmodium spp. and is transmitted to humans through the bite of infected Anopheles mosquitoes. Malaria has reached alarming levels in some parts of the world mainly due to the emergence of drug-resistant parasites as well as insecticide-resistant vectors [18Prasad K.J. Emerging and re-emerging parasitic diseases JIMSA 2010; 23(1): 46.]. Malaysia is facing tremendous challenges in regard to the increasing incidence and disease burden of urban malaria due to unplanned development around large cities. One of such challenges is that the parasites Plasmodium falciparum and Plasmodium vivax is naturally found in all of the Association of Southeast Asian Nations (ASEAN). Although Malaysia had successfully controlled the spread of both Plasmodium falciparum and Plasmodium vivax, it seems that the incidence of Plasmodium malariae and Plasmodium knowlesi has significantly increased over the past decade [49William T, Jelip J, Menon J, et al. Changing epidemiology of malaria in Sabah, Malaysia: Increasing incidence of Plasmodium knowlesi. Malar J 2014; 13: 390.[http://dx.doi.org/10.1186/1475-2875-13-390] [PMID: 25272973] ]. Plasmodium knowlesi, also known as the fifth human malaria parasite, is naturally found in long-tailed and pig-tailed macaques [50Moyes CL, Henry AJ, Golding N, et al. Defining the geographical range of the Plasmodium knowlesi reservoir. PLoS Negl Trop Dis 2014; 8(3): e2780.[http://dx.doi.org/10.1371/journal.pntd.0002780] [PMID: 24676231] ]. During an emerging zoonosis, significant mutations that occur in prokaryotic pathogens can be traced. However, when it comes to eukaryotic parasites, there are many challenges faced [51Liu W, Li Y, Learn GH, et al. Origin of the human malaria parasite Plasmodium falciparum in gorillas. Nature 2010; 467(7314): 420-5.[http://dx.doi.org/10.1038/nature09442] [PMID: 20864995] ]. It is now known that both P. falciparum and P. vivax have been endemic for many years [51Liu W, Li Y, Learn GH, et al. Origin of the human malaria parasite Plasmodium falciparum in gorillas. Nature 2010; 467(7314): 420-5.[http://dx.doi.org/10.1038/nature09442] [PMID: 20864995] ]. In contrast, P. knowlesi infections were rarely detected in humans only until recently when a large number of cases started to be reported in the states of Sabah and Sarawak [52Singh B, Kim Sung L, Matusop A, et al. A large focus of naturally acquired Plasmodium knowlesi infections in human beings. Lancet 2004; 363(9414): 1017-24.[http://dx.doi.org/10.1016/S0140-6736(04)15836-4] [PMID: 15051 281] ]. P. knowlesi is now a major cause of human malaria in Malaysia particularly in these two states threatening the progress of control programs. The first case of human knowlesi malaria was reported from Peninsular Malaysia back in 1965 [53Chin W, Contacos PG, Coatney GR, Kimball HR. A naturally acquired quotidian-type malaria in man transferable to monkeys. Science 1965; 149(3686): 865-5.[http://dx.doi.org/10.1126/science.149.3686.865] [PMID: 14332847] ] followed by a second case a few years later [54Fong YL, Cadigan FC, Coatney GR. A presumptive case of naturally occurring Plasmodium knowlesi malaria in man in Malaysia. Trans R Soc Trop Med Hyg 1971; 65(6): 839-40.[http://dx.doi.org/10.1016/0035-9203(71)90103-9] [PMID: 5003320] ]. However, large numbers of human infections began to be reported in the state of Sarawak in the early 2000s [55Singh B, Kim Sung L, Matusop A, et al. A large focus of naturally acquired Plasmodium knowlesi infections in human beings. Lancet 2004; 363(9414): 1017-24.[http://dx.doi.org/10.1016/S0140-6736(04)15836-4] [PMID: 15051 281] ]. Ever since, P. knowlesi has become the major cause of human malaria across the states of Sabah and Sarawak [56Barber BE, William T, Jikal M, et al. Plasmodium knowlesi malaria in children. Emerg Infect Dis 2011; 17(5): 814-20.[http://dx.doi.org/10.3201/eid1705.101489] [PMID: 21529389] , 57Cox-Singh J, Davis TM, Lee KS, et al. Plasmodium knowlesi malaria in humans is widely distributed and potentially life threatening. Clin Infect Dis 2008; 46(2): 165-71.[http://dx.doi.org/10.1086/524888] [PMID: 18171245] ]. Despite the success of malaria control programs in Malaysia, Plasmodium knowlesi has emerged as a zoonotic species and a large number of cases were first reported in 2004 in Sarawak [49William T, Jelip J, Menon J, et al. Changing epidemiology of malaria in Sabah, Malaysia: Increasing incidence of Plasmodium knowlesi. Malar J 2014; 13: 390.[http://dx.doi.org/10.1186/1475-2875-13-390] [PMID: 25272973] ] followed by Peninsular Malaysia later on [50Moyes CL, Henry AJ, Golding N, et al. Defining the geographical range of the Plasmodium knowlesi reservoir. PLoS Negl Trop Dis 2014; 8(3): e2780.[http://dx.doi.org/10.1371/journal.pntd.0002780] [PMID: 24676231] , 58Singh B, Daneshvar C. Human infections and detection of Plasmodium knowlesi. Clin Microbiol Rev 2013; 26(2): 165-84.[http://dx.doi.org/10.1128/CMR.00079-12] [PMID: 23554413] ]. In recent years, the epidemiology of malaria is becoming more complex in Malaysia. There is a shift towards infections among men and adults rather than women and children [59Cotter C, Sturrock HJ, Hsiang MS, et al. The changing epidemiology of malaria elimination: New strategies for new challenges. Lancet 2013; 382(9895): 900-11.[http://dx.doi.org/10.1016/S0140-6736(13)60310-4] [PMID: 23594 387] ]. This can be attributed to the fact that men are engaged in more outdoors activates such as plantation and forest works exposing them to the bites of infected vectors [60Trung HD, Bortel WV, Sochantha T, Keokenchanh K, Briët OJ, Coosemans M. Behavioural heterogeneity of Anopheles species in ecologically different localities in Southeast Asia: A challenge for vector control. Trop Med Int Health 2005; 10(3): 251-62.[http://dx.doi.org/10.1111/j.1365-3156.2004.01378.x] [PMID: 1573 0510] ].

There are many factors that contribute to the emergence of P. knowlesi malaria in Malaysia. In 2009, the highest percentage of P. knowlesi malaria was reported to be 87% at the Kudat district hospital in the state of Sabah [56Barber BE, William T, Jikal M, et al. Plasmodium knowlesi malaria in children. Emerg Infect Dis 2011; 17(5): 814-20.[http://dx.doi.org/10.3201/eid1705.101489] [PMID: 21529389] ]. In 2013, an increase in the prevalence of P. knowlesi in Sabah was reported [61William T, Rahman HA, Jelip J, et al. Increasing incidence of Plasmodium knowlesi malaria following control of P. falciparum and P. vivax Malaria in Sabah, Malaysia. PLoS Negl Trop Dis 2013; 7(1): e2026.[http://dx.doi.org/10.1371/journal.pntd.0002026] [PMID: 23359830] ] as a result of significant deforestation that led to the increased exposure to the arthropod vectors [61William T, Rahman HA, Jelip J, et al. Increasing incidence of Plasmodium knowlesi malaria following control of P. falciparum and P. vivax Malaria in Sabah, Malaysia. PLoS Negl Trop Dis 2013; 7(1): e2026.[http://dx.doi.org/10.1371/journal.pntd.0002026] [PMID: 23359830] ]. Such activities have also led to vector behavioral changes as seen in the Kinabatangan region where Anopheles Donaldi replaced the previously dominant Anopheles Balabacensis [62Vythilingam I, Chan ST, Shanmugratnam C, Tanrang H, Chooi KH. The impact of development and malaria control activities on its vectors in the Kinabatangan area of Sabah, East Malaysia. Acta Trop 2005; 96(1): 24-30.[http://dx.doi.org/10.1016/j.actatropica.2005.06.022] [PMID: 16076 459] ]. In 2015, Plasmodium knowlesi was reported in humans as an admixture of two highly divergent parasite populations, each associated with different macaque reservoir host species [63Divis PCS. S.B., Anderios F., Hisam S., Matusop A., Kocken C.H., Assefa S.A., Duffy C.W., Conway D.J., Admixture in humans of two divergent Plasmodium knowlesi populations associated with different macaque host species. PLoS Pathog 2015.[http://dx.doi.org/10.1371/journal.ppat.1004888] ]. Moreover, the resistance of the Plasmodium spp. to antimalarial drugs has led to great difficulties in managing the disease. Furthermore, what makes the diagnosis of P. knowlesi difficult is that microscopically it is indistinguishable from P. malariae [61William T, Rahman HA, Jelip J, et al. Increasing incidence of Plasmodium knowlesi malaria following control of P. falciparum and P. vivax Malaria in Sabah, Malaysia. PLoS Negl Trop Dis 2013; 7(1): e2026.[http://dx.doi.org/10.1371/journal.pntd.0002026] [PMID: 23359830] ]. Therefore, the ministry of health of Malaysia along with academic and research institutes should increase their effort to raise public awareness as well as implement the use of point-of-care molecular techniques to characterize mixed infections amongst which most of them go misinterpreted or underreported and thus preventing their emergence.

2.8. Toxoplasmosis

Toxoplasmosis is a re-emerging parasitic infectious disease caused by a protozoa Toxoplasma gondii [64Nissapatorn V. Toxoplasmosis: A silent threat in Southeast Asia. J Parasitol 2007; 2(1): 1-12.[http://dx.doi.org/10.3923/jp.2007.1.12] [PMID: 17436935] ] that continues to be an important cause of morbidity in the tropics. The prevalence of Toxoplasmosis in Malaysia has significantly increased in the last three decades. In 1983, a study was conducted at the Ophthalmology Clinic in Universiti Kebangsaan Malaysia (UKM)reported 31 cases of ocular Toxoplasmosis [65P.L., L.V.K.E.a.T.. Ocular Toxoplasmosis in Malaysia. Medicla Journal of Malaysia 1983; 38(3)]. Studies have shown that Malays have the highest incidence of toxoplasmosis followed by Indians and Chinese [65P.L., L.V.K.E.a.T.. Ocular Toxoplasmosis in Malaysia. Medicla Journal of Malaysia 1983; 38(3)]. One of the common risk factors to acquire a Toxoplasma infection is the direct contact with infected cats, consumption of uncooked meat and less commonly through blood product or organ transplantation [64Nissapatorn V. Toxoplasmosis: A silent threat in Southeast Asia. J Parasitol 2007; 2(1): 1-12.[http://dx.doi.org/10.3923/jp.2007.1.12] [PMID: 17436935] ]. Early studies on the seroprevalence of toxoplasmosis in Malaysian pregnant women estimated it to be 27.4% [66Cheah WC, Fah CS, Fook CW. Pattern of toxoplasma antibodies in Malaysian pregnant women. Med J Malaysia 1975; 29(4): 275-9.[PMID: 1196176] ] however there has been a significant increase in the percentage of this disease in this group of the population as of 1990 onwards [67Nissapatorn V, Abdullah KA. Review on human toxoplasmosis in Malaysia: The past, present and prospective future. Southeast Asian J Trop Med Public Health 2004; 35(1): 24-30.[PMID: 15272740] ]. Moreover, toxoplasmosis was found to be directly associated with abortions and stillbirths [64Nissapatorn V. Toxoplasmosis: A silent threat in Southeast Asia. J Parasitol 2007; 2(1): 1-12.[http://dx.doi.org/10.3923/jp.2007.1.12] [PMID: 17436935] ]. There has been a high prevalence of toxoplasmosis in Malaysia among HIV/AIDS individuals [64Nissapatorn V. Toxoplasmosis: A silent threat in Southeast Asia. J Parasitol 2007; 2(1): 1-12.[http://dx.doi.org/10.3923/jp.2007.1.12] [PMID: 17436935] ]. In 2003, a total of 301 serum specimens of HIV/AIDS patients were tested for anti-Toxoplasma IgG antibody by ELISA [68Nissapatorn V, Lee CK, Cho SM, et al. Toxoplasmosis in HIV/AIDS patients in Malaysia. Southeast Asian J Trop Med Public Health 2003; 34(Suppl. 2): 80-5.[PMID: 19238664] ]. Results showed that the seroprevalence was 41.2% with a higher percentage among the Malays in the Malay, Chinese than Indians [68Nissapatorn V, Lee CK, Cho SM, et al. Toxoplasmosis in HIV/AIDS patients in Malaysia. Southeast Asian J Trop Med Public Health 2003; 34(Suppl. 2): 80-5.[PMID: 19238664] ]. From 2007 to 2010, a study evaluated the seroprevalence of Toxoplasma gondii among 495 Orang Asli living in Peninsular Malaysia with an overall seroprevalence of 37.0% [69Ngui R, Lim YA, Amir NF, Nissapatorn V, Mahmud R. Sero- prevalence and sources of toxoplasmosis among Orang Asli (indigenous) communities in Peninsular Malaysia. Am J Trop Med Hyg 2011; 85(4): 660-6.[http://dx.doi.org/10.4269/ajtmh.2011.11-0058] [PMID: 21976569] ]. Given the high prevalence of toxoplasmosis among Orang Asli pregnant women, health surveillance programs in such communities should start early during the antenatal routine check-up [70Ngui R, Lim YA, Amir NF, Nissapatorn V, Mahmud R. Seropre- valence and sources of toxoplasmosis among Orang Asli (indigenous) communities in Peninsular Malaysia. Am J Trop Med Hyg 2011; 85(4): 660-6.[http://dx.doi.org/10.4269/ajtmh.2011.11-0058] [PMID: 21976569] ]. In 2017, the seroprevalence of Toxoplasma gondii among migrant workers in Peninsular Malaysia was evaluated [71Sahimin N, Lim YA, Ariffin F, et al. Socio-demographic determinants of Toxoplasma gondii seroprevalence in migrant workers of Peninsular Malaysia. Parasit Vectors 2017; 10(238)]. Their results showed that there was an increased prevalence of 57.4% compared to previous reports [72Chan BTE. A.R., Noor Hayati MI, Toxoplasmosis among Indonesian Migrant Workers in Malaysia. Malays J Med Sci 2009; 5: 31-7.]. Southeast Asia including Malaysia harbors a large variety of ecological niches that favor the spread and transmission of Toxoplasma spp. and with the rapid development that is happening in the region, the incidence of toxoplasmosis might be on the rise in Malaysia leading to its re-emergence. Therefore, surveillance programs should be initiated to facilitate early diagnosis and treatment [69Ngui R, Lim YA, Amir NF, Nissapatorn V, Mahmud R. Sero- prevalence and sources of toxoplasmosis among Orang Asli (indigenous) communities in Peninsular Malaysia. Am J Trop Med Hyg 2011; 85(4): 660-6.[http://dx.doi.org/10.4269/ajtmh.2011.11-0058] [PMID: 21976569] ]. Moreover, the role of domestic cats and environmental contamination with Toxoplasma oocyst must be addressed in order to implement preventative measures.

Fig. (1)
Map of Malaysia indicating the distribution of reported emerging and re-emerging parasitic infectious diseases.


2.9. Trypanosomiasis

Trypanosomiasis or Human African Trypanosomiasis (HAT) is an emerging vector-borne parasitic infectious disease caused by infection with protozoan the parasite Trypanosoma species. They are transmitted to humans by tsetse fly bites which have acquired their infection from human beings or from animals harboring human pathogenic parasites [73 (WHO), W.h.o. Trypanosomiasis, human African (sleeping sickness). 2018; Available from: http://www. who. int/ news- room/ fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness)]. Animal trypanosomiasis existed in Malaysia for many decades as it was reported in cattle and horse. Malaysia is considered endemic for animal trypanosomiasis caused by Trypanosoma evansi [74Cheah TS, Sani RA, Chandrawathani P, Bahri S, Dahlan I. Epidemiology of Trypanosoma evansi infection in crossbred dairy cattle in Malaysia. Trop Anim Health Prod 1999; 31(1): 25-31.[http://dx.doi.org/10.1023/A:1005177300345] [PMID: 10399814] ]. In 1996, it was reported that trypanosomiasis in the cattle caused significant losses in milk production and body weight [75Cheah TS, Sani RA, Chandrawathani P, Bahri S, Dahlan I. Prevalence of T evansi in a dairy cattle farm in 8th 1996.] and that stable flies, as well as horse flies, can transmit Trypanosoma evansi in Malaysian cattle [76Erwanas AI. Vectors of veterinary importance in Malaysia: A survey of biting flies in relation to trypanosomiasis in Perak Malaysian journal of veterinary research 2015; 6(1): 89-96.]. Deer farming has become popular in Malaysia recently and there is a potential for trypanosomiasis to occur in farmed deer. In 2007, a livestock deer breeding center located in the state of Perak was the place to investigate an outbreak as well as the seroprevalence of Trypanosoma evansi [77Adrian MS, Sani RA, Hassan L, Wong MT. Outbreaks of trypanosomiasis and the seroprevalence of T. evansi in a deer breeding centre in Perak, Malaysia. Trop Anim Health Prod 2010; 42(2): 145-50.[http://dx.doi.org/10.1007/s11250-009-9406-8] [PMID: 19642008] ]. Although human trypanosomiasis is not yet considered a health problem in Southeast Asia including Malaysia [78V., S.S.T.a.W., Emerging human trypanosomiasis in Southeast Asia: A coming new threat? J Nat Sci 2015; 1(1): 1-2.], but cross-species zoonosis from local infected animals [79Truc P, et al. Atypical human infections by animal trypanosomes. LoS Neglected Trop Dis 2013; 7(9): 1-7.]. The existence of human trypanosomiasis from neighboring Thailand, reporting cases of trypanosomiasis in cattle from neighboring Indonesia, can all lead to its emergence. Therefore, improving diagnostic tests, awareness, and field investigations can aid to detect both human and animal cases (Fig. 1).

3. FACTORS INFLUENCING EMERGENCE OF INFECTIOUS DISEASE

There are many factors that influence the emergence and re-emergence of parasitic infectious diseases in Malaysia; those include the displacement of human populations due to natural disasters, deliberate changes in biodiversity due to deforestation, influx of immigrant foreign workers from endemic countries, poor hygienic practices, lack of proper healthcare infrastructure in some rural areas, as well as some local food habits [6Atehmengo NL, Nnagbo CS. Emerging animal parasitic diseases: A global overview and appropriate strategies for their monitoring and surveillance in Nigeria. Open Microbiol J 2014; 8: 87-94.[http://dx.doi.org/10.2174/1874285801408010087] [PMID: 25328553] ]. Some of these factors will be discussed as follows:

3.1. Displacement of Human Populations

The mass movement of human populations from their homes or relocating them in temporary refugee camps as seen during floods is a serious problem in Malaysia particularly during the monsoon season [6Atehmengo NL, Nnagbo CS. Emerging animal parasitic diseases: A global overview and appropriate strategies for their monitoring and surveillance in Nigeria. Open Microbiol J 2014; 8: 87-94.[http://dx.doi.org/10.2174/1874285801408010087] [PMID: 25328553] ]. This sudden displacement of population adversely affects the safe disposal of human excreta and often destroys drainage systems leading to direct exposure to many intestinal parasites as well as their potential vectors. One of the worst floods to hit Malaysia occurred in the city of Kota Bharu of the state Kelantan back in 2014 when approximately 104,000 people were displaced from their homes exposing them to many diseases. Luckily and with great efforts by many volunteers, the situation was handled with efficient distribution of aid .

More recently in 2018, two lives were claimed and nearly 12,000 people were evacuated from their homes in the state of Pahang [80Times TS. Times, T.S. Two dead, nearly 12,000 evacuated in Malaysia floods. 2018; Available from: https://www. straitstimes. com/ asia/ se-asia / two-dead-nearly-12000-evacuated-in-malaysia-floods]. It was reported by Malaysia's disaster management agency that the flood victims were sheltered at relief centers in the states of Johor, Terengganu, Pahang, and Sabah. It was learned later that the flood was mainly due to the continuous downpour and the inability of drains in those places to accommodate such water flow. Therefore, more efforts from states and federal governments are required to improve the drainage systems in such areas.

3.2. Deliberate Changes in Biodiversity

Biodiversity is defined as the variability among terrestrial, marine and aquatic living organisms [81Hosseini PR. MJN, Prieur-Richard AH, Ezenwa VO, Bailly X, Rizzoli A, Suza G, Vittecoq M, Garcıa-Pen GE, Daszak P, Guegan JF, Roche B, Does the impact of biodiversity differ between emerging and endemic pathogens? The need to separate the concepts of hazard and risk 2017; 1-7.]. For many zoonotic parasites, direct exposure with wildlife reservoirs and vectors is a major risk factor [82Sumilo D. A.L., Bormane A., Vasilenko V., Golovljova I., Randolph S.E., Sutherland C., Climate change cannot explain the upsurge of tick-borne encephalitis in the Baltics. PLoS One 2007; (6): 1-11.] leading to what is termed as ‘host-jumping’ where an animal parasite infects humans due to activities occurring in proximity to wildlife areas [81Hosseini PR. MJN, Prieur-Richard AH, Ezenwa VO, Bailly X, Rizzoli A, Suza G, Vittecoq M, Garcıa-Pen GE, Daszak P, Guegan JF, Roche B, Does the impact of biodiversity differ between emerging and endemic pathogens? The need to separate the concepts of hazard and risk 2017; 1-7.]. Malaysia has witnessed rapid development over the past three decades in terms of urbanization, deforestation and road construction. Such activities have subsequently led to deforestation as well as changing the ecosystem of some of the animals and insects that are potential vectors for many parasitic infectious diseases [83Patz JA, Graczyk TK, Geller N, Vittor AY. Effects of environmental change on emerging parasitic diseases. Int J Parasitol 2000; 30(12-13): 1395-405.[http://dx.doi.org/10.1016/S0020-7519(00)00141-7] [PMID: 11113 264] ]. Such urbanization has allowed some parasitic infections to significantly increase from isolated rural areas to larger communities. As a consequence, this emerging infection (disease) will spread even further among the population through the use of modern transportation [1Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis 1995; 1(1): 7-15.[http://dx.doi.org/10.3201/eid0101.950102] [PMID: 8903148] ]. Displacement of wildlife can also result in global warming which subsequently can lead to the spread of infections to human populations [84Hoberg EP, Polley L, Jenkins EJ, Kutz SJ, Veitch AM, Elkin BT. Integrated approaches and empirical models for investigation of parasitic diseases in northern wildlife. Emerg Infect Dis 2008; 14(1): 10-7.[http://dx.doi.org/10.3201/eid1401.071119] [PMID: 18258071] ]. For example, land changes due to the construction of residential and retail buildings in Malaysia can cause habitat destruction, fragmentation as well as local species extinction which in turn contribute to the loss of biodiversity [81Hosseini PR. MJN, Prieur-Richard AH, Ezenwa VO, Bailly X, Rizzoli A, Suza G, Vittecoq M, Garcıa-Pen GE, Daszak P, Guegan JF, Roche B, Does the impact of biodiversity differ between emerging and endemic pathogens? The need to separate the concepts of hazard and risk 2017; 1-7.]. Therefore local authorities along with the developers must properly plan the use of land to prevent exposure or drastic changes to wildlife hence preventing the emergence and re-emergence of parasitic diseases.

3.3. Influx of Immigrant Foreign Workers

The stable growing economic conditions in Malaysia seem to encourage the movement of large numbers of immigrant workers, those coming from endemic areas with various parasitic infectious diseases [1Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis 1995; 1(1): 7-15.[http://dx.doi.org/10.3201/eid0101.950102] [PMID: 8903148] ]. Malaysia is always lacking unskilled labor hence it attracts migrants to sustain its economic development. Accordingly to the Malaysian home ministry, there are more than 1.7 million foreign workers in Malaysia as of June 2017 and majority from Indonesia [85 More than 1.7 million foreign workers in Malaysia; majority from Indonesia, in The New Straits Times New Straits Times 2017: Malaysia ]. The presence of such large numbers of foreigners is a major healthcare concern for Malaysia. Such concern is reflected upon formulating health policies. The problem in monitoring emerging and re-emerging parasitic diseases is that advanced surveillance and monitoring systems are readily available in developed nations rather than developing countries that are directly affected by such diseases [86Jones KE, Patel NG, Levy MA, et al. Global trends in emerging infectious diseases. Nature 2008; 451(7181): 990-3.[http://dx.doi.org/10.1038/nature06536] [PMID: 18288193] ]. Priority should be given to set up 'smart surveillance' measures in hotspots across Malaysia.

4. DISCUSSION

All of the factors discussed above along with the ongoing evolution of microbial variants and drug resistance contribute in one way or another in putting Malaysian people at risk of being infected or affected by one or more of these emerging and re-emerging parasitic diseases. It seems that such diseases will continue to appear leading to unpredictable outbreaks or epidemics that challenge healthcare personnel and emphasize the urgent need for effective surveillance and control measures. Despite the challenges faced, Malaysia is strongly committed to curb the spread of these diseases. One good example is the ‘food handlers’ training programme’ adopted by the Ministry of Health in Malaysia in 1996 to ensure hygienic practices during handling, preparation and sale of food and prevent the spread of food-borne diseases [87Soon J, Singh H, Baines R. Foodborne diseases in Malaysia: A review. Food Control 2011; 22(6): 823-30.[http://dx.doi.org/10.1016/j.foodcont.2010.12.011] ]. Moreover, Malaysia has established indicator-based and event-based surveillance systems as well as a web-based early outbreak reporting system called e-wabak which has the potential to include all hazards. Orang Asli in rural Malaysia is by far the most vulnerable population to polyparasitism [10Al-Delaimy AK, Al-Mekhlafi HM, Nasr NA, et al. Epidemiology of intestinal polyparasitism among Orang Asli school children in rural Malaysia. PLoS Negl Trop Dis 2014; 8(8): e3074.[http://dx.doi.org/10.1371/journal.pntd.0003074] [PMID: 25144662] ]. There is an urgent need to improve the quality of life of Orang Asli and implement awareness programmes to reduce the incidence of such disease particularly among children [10Al-Delaimy AK, Al-Mekhlafi HM, Nasr NA, et al. Epidemiology of intestinal polyparasitism among Orang Asli school children in rural Malaysia. PLoS Negl Trop Dis 2014; 8(8): e3074.[http://dx.doi.org/10.1371/journal.pntd.0003074] [PMID: 25144662] ]. Preserving wildlife should be taken into consideration in the risk analysis framework to prevent zoonoses [88Kruse H, Kirkemo A-M, Handeland K. Wildlife as source of zoonotic infections. Emerg Infect Dis 2004; 10(12): 2067-72.[http://dx.doi.org/10.3201/eid1012.040707] [PMID: 15663840] ]. More research is needed to investigate the epidemiology of zoonoses in Malaysia as well as improve and implement the use of point-of-care diagnostic tools particularly in the remote and rural areas [88Kruse H, Kirkemo A-M, Handeland K. Wildlife as source of zoonotic infections. Emerg Infect Dis 2004; 10(12): 2067-72.[http://dx.doi.org/10.3201/eid1012.040707] [PMID: 15663840] ]. The way forward for Malaysia to reduce the risk of emerging and re-emerging parasitic diseases is through the scope of World Health Organization (WHO) International Health Regulations (IHR) 2005 and OIE Terrestrial Animal Health Code 2011 with the ‘One Health’ approach to collaboration. Updating epidemiological databases will help characterize host-pathogen interactions and provide a better understanding of disease dynamics. Last but not least, health education and health awareness across the nation go a long way in enhancing prevention and awareness among the general public on intestinal parasitic infections.

CONCLUSION

The lack of awareness, poor hygienic practices among socioeconomically disadvantaged communities and the rapid influx of immigrant workers are major factors that contribute to the emergence and re-emergence of parasitic infectious diseases in Malaysia. Therefore, raising public awareness, developing robust public health infrastructure and implementing point-of-care diagnostics will help curb the spread of such diseases not only in Malaysia but in Southeast Asia as well.

CONSENT FOR PUBLICATION

Not applicable.

AVAILABILITY OF DATA AND MATERIALS

The authors confirm that the data supporting the findings of this study are available within the article [10] at [10.1371/ journal.pntd.0003074], article [87] at [10.1016/j.foodcont.2010 .12.011], and article [88] at [10.3201/ eid1012.040707].

FUNDING

The authors would like to thank the research management center at MAHSA University for providing us with the finical support through the research grant (RP68-09/14) to conduct this review.

CONFLICT OF INTEREST

The authors declare no conflict of interest, financial or otherwise.

ACKNOWLEDGEMENTS

The authors would like to thank the management of MAHSA University, the Dean of the Faculty of Medicine & Biomedical Sciences and the Head of Department of Microbiology/ Parasitology for their support in providing all the logistics, assistance, and guidance needed to write this review.

REFERENCES

[1] Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis 1995; 1(1): 7-15.[http://dx.doi.org/10.3201/eid0101.950102] [PMID: 8903148]
[2] Kuiken T, Leighton FA, Fouchier RA, et al. Public health. Pathogen surveillance in animals. Science 2005; 309(5741): 1680-1.[http://dx.doi.org/10.1126/science.1113310] [PMID: 16150997]
[3] Weiss RA, McMichael AJ. Social and environmental risk factors in the emergence of infectious diseases. Nat Med 2004; 10(12): S70-6.[http://dx.doi.org/10.1038/nm1150] [PMID: 15577934]
[4] Kit LS. Emerging and re-emerging diseases in Malaysia. Asia Pac J Public Health 2002; 14(1): 6-8.[http://dx.doi.org/10.1177/101053950201400103] [PMID: 12597511]
[5] Johnson PT, Thieltges DW. Diversity, decoys and the dilution effect: How ecological communities affect disease risk. J Exp Biol 2010; 213(6): 961-70.[http://dx.doi.org/10.1242/jeb.037721] [PMID: 20190121]
[6] Atehmengo NL, Nnagbo CS. Emerging animal parasitic diseases: A global overview and appropriate strategies for their monitoring and surveillance in Nigeria. Open Microbiol J 2014; 8: 87-94.[http://dx.doi.org/10.2174/1874285801408010087] [PMID: 25328553]
[7] Stanley SL Jr. Amoebiasis. Lancet 2003; 361(9362): 1025-34.[http://dx.doi.org/10.1016/S0140-6736(03)12830-9] [PMID: 12660 071]
[8] Goh KL, Wong NW, Paramsothy M, Nojeg M, Somasundaram K. Liver abscess in the tropics: Experience in the University Hospital, Kuala Lumpur. Postgrad Med J 1987; 63(741): 551-4.[http://dx.doi.org/10.1136/pgmj.63.741.551] [PMID: 3658864]
[9] Anuar TS, A MH, Abdul Ghani MK, et al. Molecular epidemiology of amoebiasis in Malaysia: highlighting the different risk factors of Entamoeba histolytica and Entamoeba dispar infections among Orang Asli communities. Int J Parasitol 2012; 42: 13-4.[http://dx.doi.org/10.1016/j.ijpara.2012.10.003]
[10] Al-Delaimy AK, Al-Mekhlafi HM, Nasr NA, et al. Epidemiology of intestinal polyparasitism among Orang Asli school children in rural Malaysia. PLoS Negl Trop Dis 2014; 8(8): e3074.[http://dx.doi.org/10.1371/journal.pntd.0003074] [PMID: 25144662]
[11] Shirley DT, Farr L, Watanabe K, Moonah S. A review of the global burden, new diagnostics, and current therapeutics for amebiasis. Open Forum Infect Dis 2018; 5(7): ofy161.[http://dx.doi.org/10.1093/ofid/ofy161] [PMID: 30046644]
[12] Gabrielli A-F, Montresor A, Chitsulo L, Engels D, Savioli L. Preventive chemotherapy in human helminthiasis: Theoretical and operational aspects. Trans R Soc Trop Med Hyg 2011; 105(12): 683-93.[http://dx.doi.org/10.1016/j.trstmh.2011.08.013] [PMID: 22040463]
[13] Pullan RL, Smith JL, Jasrasaria R, Brooker SJ. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010. Parasit Vectors 2014; 7(1): 37.[http://dx.doi.org/10.1186/1756-3305-7-37] [PMID: 24447578]
[14] Bundy DA, Kan SP, Rose R. Age-related prevalence, intensity and frequency distribution of gastrointestinal helminth infection in urban slum children from Kuala Lumpur, Malaysia. Trans R Soc Trop Med Hyg 1988; 82(2): 289-94.[http://dx.doi.org/10.1016/0035-9203(88)90450-6] [PMID: 3188158]
[15] Nor Aza SAaJA. Parasitic infections in human communities living on the fringes of the crocker range park Sabah, Malaysia ASEAN Review of Biodiversity and Environmental Conservation (ARBEC) 2003.
[16] Sahimin N, L.Y.A.L. , Ariffin F, Behnke JM, Lewis JW, Mohd Zain SN. Migrant workers in Malaysia: Current implications of sociodemographic and environmental characteristics in the transmission of intestinal parasitic infections. PLoS Negl Trop Dis 2016; 1-17.
[17] F.F., L., Stop the bugs at the gate in The Star Online 2017: Malaysia
[18] Prasad K.J. Emerging and re-emerging parasitic diseases JIMSA 2010; 23(1): 46.
[19] Zarlenga DS, Trout JM. Concentrating, purifying and detecting waterborne parasites. Vet Parasitol 2004; 126(1-2): 195-217.[http://dx.doi.org/10.1016/j.vetpar.2004.09.001] [PMID: 15567585]
[20] Anuar TS, Ghani MK, Azreen SN, Salleh FM, Moktar N. Blastocystis infection in Malaysia: Evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli. Parasit Vectors 2013; 6: 40.[http://dx.doi.org/10.1186/1756-3305-6-40] [PMID: 23433099]
[21] Ithoi I. Occurrence of blastocystis in water of two rivers from recreational areas in malaysia J Parasitol Res, 2011 2011.
[22] Abdulsalam AM, Ithoi I, Al-Mekhlafi HM, Ahmed A, Surin J, Mak JW. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren. Parasitology 2012; 139(8): 1014-20.[http://dx.doi.org/10.1017/S0031182012000340] [PMID: 22444778]
[23] Tan TC, Tan PC, Sharma R, Sugnaseelan S, Suresh KG. Genetic diversity of caprine blastocystis from peninsular malaysia. Parasitol Res 2013; 112(1): 85-9.[http://dx.doi.org/10.1007/s00436-012-3107-3] [PMID: 22961236]
[24] Nithyamathi K, Chandramathi S, Kumar S. Predominance of Blastocystis sp. infection among school children in Peninsular Malaysia. PLoS One 2016; 11(2): e0136709.[http://dx.doi.org/10.1371/journal.pone.0136709] [PMID: 26914483]
[25] Zaki M, Zaman V, Sheikh NA. Resistance of blastocystis hominis cysts to chlorine. J Pak Med Assoc 1996; 46(8): 178-9.[PMID: 8936976]
[26] Yoshikawa H, Yoshida K, Nakajima A, Yamanari K, Iwatani S, Kimata I. Fecal-oral transmission of the cyst form of Blastocystis hominis in rats. Parasitol Res 2004; 94(6): 391-6.[http://dx.doi.org/10.1007/s00436-004-1230-5] [PMID: 15480786]
[27] Hoerr FJ, Current WL, Haynes TB. Fatal cryptosporidiosis in quail. Avian Dis 1986; 30(2): 421-5.[http://dx.doi.org/10.2307/1590550] [PMID: 3729889]
[28] Lim Yal RM, Shukri MM. Cryptosporidiosis among birds and bird handlers at Zoo Negara, Malaysia. Southeast Asian J Trop Med Public Health 2007; 38: 19-26.
[29] Mahdy MAK. S.J., Al-Mekhlafi H.M., Current situation of Giardia and Cryptosporidium among Orang Asli (aboriginal) communities in Pahang, Malaysia. Southeast Asian J Trop Med Public Health 2007; 38: 27-31.
[30] Rossle NF. L.B., Malik A.S., Fadzli F.M., Abu N.A., Cryptosporidiosis among children with diarrhea admitted to Hospital Selayang and Hospital Sungai Buloh, Selangor, Malaysia. J Trop Med Parasitol 2012; 35(2): 55-62.
[31] Mohd Zain SN. Giardia duodenalis and Cryptosporidium parvum infection status among migrant workers in Peninsular Malaysia in British Society for Parasitology 2017.
[32] Shrivastava AK, Kumar S, Smith WA, Sahu PS. Revisiting the global problem of cryptosporidiosis and recommendations. Trop Parasitol 2017; 7(1): 8-17.[PMID: 28459010]
[33] Kwa B. Environmental change, development and vectorborne disease: Malaysia’s experience with filariasis, scrub typhus and dengue. Environ Dev Sustain 2008; 10(2): 209-17.[http://dx.doi.org/10.1007/s10668-006-9060-5]
[34] Tan LH, Fong MY, Mahmud R, Muslim A, Lau YL, Kamarulzaman A. Zoonotic Brugia pahangi filariasis in a suburbia of Kuala Lumpur City, Malaysia. Parasitol Int 2011; 60(1): 111-3.[http://dx.doi.org/10.1016/j.parint.2010.09.010] [PMID: 20951228]
[35] Rahmah N, Lim BH, Azian H, Ramelah TS, Rohana AR. Short communication: Use of a recombinant antigen-based ELISA to determine prevalence of brugian filariasis among Malaysian schoolchildren near Pasir Mas, Kelantan-Thailand border. Trop Med Int Health 2003; 8(2): 158-63.[http://dx.doi.org/10.1046/j.1365-3156.2003.01004.x] [PMID: 12581 442]
[36] Jureen J-MCaR. imported asymptomatic bancroftian filariasis discovered from a Plasmodium vivax Infected Patient: A case report from Singapore Case reports in infectious diseases 2017.
[37] Rahmah N, Anuar AK, Ariff RH, et al. Use of antifilarial IgG4-ELISA to detect Brugia malayi infection in an endemic area of Malaysia. Trop Med Int Health 1998; 3(3): 184-8.[http://dx.doi.org/10.1046/j.1365-3156.1998.00229.x] [PMID: 9593 356]
[38] Supali T, Rahmah N, Djuardi Y, Sartono E, Rückert P, Fischer P. Detection of filaria-specific IgG4 antibodies using Brugia Rapid test in individuals from an area highly endemic for Brugia timori. Acta Trop 2004; 90(3): 255-61.[http://dx.doi.org/10.1016/j.actatropica.2004.02.001] [PMID: 15099 812]
[39] Jamail M, Andrew K, Junaidi D, Krishnan AK, Faizal M, Rahmah N. Field validation of sensitivity and specificity of rapid test for detection of Brugia malayi infection. Trop Med Int Health 2005; 10(1): 99-104.[http://dx.doi.org/10.1111/j.1365-3156.2004.01334.x] [PMID: 15655 019]
[40] Al-Mekhlafi HM, Al-Maktari MT, Jani R, et al. Burden of Giardia duodenalis infection and its adverse effects on growth of school children in rural Malaysia. PLoS Negl Trop Dis 2013; 7(10): e2516.[http://dx.doi.org/10.1371/journal.pntd.0002516] [PMID: 24205426]
[41] Al-Mekhlafi HM, Surin J, Sallam AA, Abdullah AW, Mahdy MA. Giardiasis and poor vitamin A status among aboriginal school children in rural Malaysia. Am J Trop Med Hyg 2010; 83(3): 523-7.[http://dx.doi.org/10.4269/ajtmh.2010.09-0371] [PMID: 20810815]
[42] Norhayati M, Penggabean M, Oothuman P, Fatmah MS. Prevalence and some risk factors of Giardia duodenalis infection in a rural community in Malaysia. Southeast Asian J Trop Med Public Health 1998; 29(4): 735-8.[PMID: 10772555]
[43] Al-Mekhlafi MS, Azlin M, Nor Aini U, et al. Giardiasis as a predictor of childhood malnutrition in Orang Asli children in Malaysia. Trans R Soc Trop Med Hyg 2005; 99(9): 686-91.[http://dx.doi.org/10.1016/j.trstmh.2005.02.006] [PMID: 15992838]
[44] Kumar T, Onichandran S, Lim YA, et al. Comparative study on waterborne parasites between Malaysia and Thailand: A new insight. Am J Trop Med Hyg 2014; 90(4): 682-9.[http://dx.doi.org/10.4269/ajtmh.13-0266] [PMID: 24567315]
[45] Lim YA, Ahmad RA, Smith HV. Current status and future trends in Cryptosporidium and Giardia epidemiology in Malaysia. J Water Health 2008; 6(2): 239-54.[http://dx.doi.org/10.2166/wh.2008.023] [PMID: 18209286]
[46] Lim YA, Iqbal A, Surin J, et al. First genetic classification of Cryptosporidium and Giardia from HIV/AIDS patients in Malaysia. Infect Genet Evol 2011; 11(5): 968-74.[http://dx.doi.org/10.1016/j.meegid.2011.03.007] [PMID: 21439404]
[47] Anuar TS, Al-Mekhlafi HM, Ghani MK, et al. Giardiasis among different tribes of Orang Asli in Malaysia: Highlighting the presence of other family members infected with Giardia intestinalis as a main risk factor. Int J Parasitol 2012; 42(9): 871-80.[http://dx.doi.org/10.1016/j.ijpara.2012.07.003] [PMID: 22846786]
[48] Lim YA, Mahdy MA, Tan TK, et al. First molecular characterization of Giardia duodenalis from goats in Malaysia. Mol Cell Probes 2013; 27(1): 28-31.[http://dx.doi.org/10.1016/j.mcp.2012.08.006] [PMID: 22971518]
[49] William T, Jelip J, Menon J, et al. Changing epidemiology of malaria in Sabah, Malaysia: Increasing incidence of Plasmodium knowlesi. Malar J 2014; 13: 390.[http://dx.doi.org/10.1186/1475-2875-13-390] [PMID: 25272973]
[50] Moyes CL, Henry AJ, Golding N, et al. Defining the geographical range of the Plasmodium knowlesi reservoir. PLoS Negl Trop Dis 2014; 8(3): e2780.[http://dx.doi.org/10.1371/journal.pntd.0002780] [PMID: 24676231]
[51] Liu W, Li Y, Learn GH, et al. Origin of the human malaria parasite Plasmodium falciparum in gorillas. Nature 2010; 467(7314): 420-5.[http://dx.doi.org/10.1038/nature09442] [PMID: 20864995]
[52] Singh B, Kim Sung L, Matusop A, et al. A large focus of naturally acquired Plasmodium knowlesi infections in human beings. Lancet 2004; 363(9414): 1017-24.[http://dx.doi.org/10.1016/S0140-6736(04)15836-4] [PMID: 15051 281]
[53] Chin W, Contacos PG, Coatney GR, Kimball HR. A naturally acquired quotidian-type malaria in man transferable to monkeys. Science 1965; 149(3686): 865-5.[http://dx.doi.org/10.1126/science.149.3686.865] [PMID: 14332847]
[54] Fong YL, Cadigan FC, Coatney GR. A presumptive case of naturally occurring Plasmodium knowlesi malaria in man in Malaysia. Trans R Soc Trop Med Hyg 1971; 65(6): 839-40.[http://dx.doi.org/10.1016/0035-9203(71)90103-9] [PMID: 5003320]
[55] Singh B, Kim Sung L, Matusop A, et al. A large focus of naturally acquired Plasmodium knowlesi infections in human beings. Lancet 2004; 363(9414): 1017-24.[http://dx.doi.org/10.1016/S0140-6736(04)15836-4] [PMID: 15051 281]
[56] Barber BE, William T, Jikal M, et al. Plasmodium knowlesi malaria in children. Emerg Infect Dis 2011; 17(5): 814-20.[http://dx.doi.org/10.3201/eid1705.101489] [PMID: 21529389]
[57] Cox-Singh J, Davis TM, Lee KS, et al. Plasmodium knowlesi malaria in humans is widely distributed and potentially life threatening. Clin Infect Dis 2008; 46(2): 165-71.[http://dx.doi.org/10.1086/524888] [PMID: 18171245]
[58] Singh B, Daneshvar C. Human infections and detection of Plasmodium knowlesi. Clin Microbiol Rev 2013; 26(2): 165-84.[http://dx.doi.org/10.1128/CMR.00079-12] [PMID: 23554413]
[59] Cotter C, Sturrock HJ, Hsiang MS, et al. The changing epidemiology of malaria elimination: New strategies for new challenges. Lancet 2013; 382(9895): 900-11.[http://dx.doi.org/10.1016/S0140-6736(13)60310-4] [PMID: 23594 387]
[60] Trung HD, Bortel WV, Sochantha T, Keokenchanh K, Briët OJ, Coosemans M. Behavioural heterogeneity of Anopheles species in ecologically different localities in Southeast Asia: A challenge for vector control. Trop Med Int Health 2005; 10(3): 251-62.[http://dx.doi.org/10.1111/j.1365-3156.2004.01378.x] [PMID: 1573 0510]
[61] William T, Rahman HA, Jelip J, et al. Increasing incidence of Plasmodium knowlesi malaria following control of P. falciparum and P. vivax Malaria in Sabah, Malaysia. PLoS Negl Trop Dis 2013; 7(1): e2026.[http://dx.doi.org/10.1371/journal.pntd.0002026] [PMID: 23359830]
[62] Vythilingam I, Chan ST, Shanmugratnam C, Tanrang H, Chooi KH. The impact of development and malaria control activities on its vectors in the Kinabatangan area of Sabah, East Malaysia. Acta Trop 2005; 96(1): 24-30.[http://dx.doi.org/10.1016/j.actatropica.2005.06.022] [PMID: 16076 459]
[63] Divis PCS. S.B., Anderios F., Hisam S., Matusop A., Kocken C.H., Assefa S.A., Duffy C.W., Conway D.J., Admixture in humans of two divergent Plasmodium knowlesi populations associated with different macaque host species. PLoS Pathog 2015.[http://dx.doi.org/10.1371/journal.ppat.1004888]
[64] Nissapatorn V. Toxoplasmosis: A silent threat in Southeast Asia. J Parasitol 2007; 2(1): 1-12.[http://dx.doi.org/10.3923/jp.2007.1.12] [PMID: 17436935]
[65] P.L., L.V.K.E.a.T.. Ocular Toxoplasmosis in Malaysia. Medicla Journal of Malaysia 1983; 38(3)
[66] Cheah WC, Fah CS, Fook CW. Pattern of toxoplasma antibodies in Malaysian pregnant women. Med J Malaysia 1975; 29(4): 275-9.[PMID: 1196176]
[67] Nissapatorn V, Abdullah KA. Review on human toxoplasmosis in Malaysia: The past, present and prospective future. Southeast Asian J Trop Med Public Health 2004; 35(1): 24-30.[PMID: 15272740]
[68] Nissapatorn V, Lee CK, Cho SM, et al. Toxoplasmosis in HIV/AIDS patients in Malaysia. Southeast Asian J Trop Med Public Health 2003; 34(Suppl. 2): 80-5.[PMID: 19238664]
[69] Ngui R, Lim YA, Amir NF, Nissapatorn V, Mahmud R. Sero- prevalence and sources of toxoplasmosis among Orang Asli (indigenous) communities in Peninsular Malaysia. Am J Trop Med Hyg 2011; 85(4): 660-6.[http://dx.doi.org/10.4269/ajtmh.2011.11-0058] [PMID: 21976569]
[70] Ngui R, Lim YA, Amir NF, Nissapatorn V, Mahmud R. Seropre- valence and sources of toxoplasmosis among Orang Asli (indigenous) communities in Peninsular Malaysia. Am J Trop Med Hyg 2011; 85(4): 660-6.[http://dx.doi.org/10.4269/ajtmh.2011.11-0058] [PMID: 21976569]
[71] Sahimin N, Lim YA, Ariffin F, et al. Socio-demographic determinants of Toxoplasma gondii seroprevalence in migrant workers of Peninsular Malaysia. Parasit Vectors 2017; 10(238)
[72] Chan BTE. A.R., Noor Hayati MI, Toxoplasmosis among Indonesian Migrant Workers in Malaysia. Malays J Med Sci 2009; 5: 31-7.
[73] (WHO), W.h.o. Trypanosomiasis, human African (sleeping sickness). 2018; Available from: http://www. who. int/ news- room/ fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness)
[74] Cheah TS, Sani RA, Chandrawathani P, Bahri S, Dahlan I. Epidemiology of Trypanosoma evansi infection in crossbred dairy cattle in Malaysia. Trop Anim Health Prod 1999; 31(1): 25-31.[http://dx.doi.org/10.1023/A:1005177300345] [PMID: 10399814]
[75] Cheah TS, Sani RA, Chandrawathani P, Bahri S, Dahlan I. Prevalence of T evansi in a dairy cattle farm in 8th 1996.
[76] Erwanas AI. Vectors of veterinary importance in Malaysia: A survey of biting flies in relation to trypanosomiasis in Perak Malaysian journal of veterinary research 2015; 6(1): 89-96.
[77] Adrian MS, Sani RA, Hassan L, Wong MT. Outbreaks of trypanosomiasis and the seroprevalence of T. evansi in a deer breeding centre in Perak, Malaysia. Trop Anim Health Prod 2010; 42(2): 145-50.[http://dx.doi.org/10.1007/s11250-009-9406-8] [PMID: 19642008]
[78] V., S.S.T.a.W., Emerging human trypanosomiasis in Southeast Asia: A coming new threat? J Nat Sci 2015; 1(1): 1-2.
[79] Truc P, et al. Atypical human infections by animal trypanosomes. LoS Neglected Trop Dis 2013; 7(9): 1-7.
[80] Times TS. Times, T.S. Two dead, nearly 12,000 evacuated in Malaysia floods. 2018; Available from: https://www. straitstimes. com/ asia/ se-asia / two-dead-nearly-12000-evacuated-in-malaysia-floods
[81] Hosseini PR. MJN, Prieur-Richard AH, Ezenwa VO, Bailly X, Rizzoli A, Suza G, Vittecoq M, Garcıa-Pen GE, Daszak P, Guegan JF, Roche B, Does the impact of biodiversity differ between emerging and endemic pathogens? The need to separate the concepts of hazard and risk 2017; 1-7.
[82] Sumilo D. A.L., Bormane A., Vasilenko V., Golovljova I., Randolph S.E., Sutherland C., Climate change cannot explain the upsurge of tick-borne encephalitis in the Baltics. PLoS One 2007; (6): 1-11.
[83] Patz JA, Graczyk TK, Geller N, Vittor AY. Effects of environmental change on emerging parasitic diseases. Int J Parasitol 2000; 30(12-13): 1395-405.[http://dx.doi.org/10.1016/S0020-7519(00)00141-7] [PMID: 11113 264]
[84] Hoberg EP, Polley L, Jenkins EJ, Kutz SJ, Veitch AM, Elkin BT. Integrated approaches and empirical models for investigation of parasitic diseases in northern wildlife. Emerg Infect Dis 2008; 14(1): 10-7.[http://dx.doi.org/10.3201/eid1401.071119] [PMID: 18258071]
[85] More than 1.7 million foreign workers in Malaysia; majority from Indonesia, in The New Straits Times New Straits Times 2017: Malaysia
[86] Jones KE, Patel NG, Levy MA, et al. Global trends in emerging infectious diseases. Nature 2008; 451(7181): 990-3.[http://dx.doi.org/10.1038/nature06536] [PMID: 18288193]
[87] Soon J, Singh H, Baines R. Foodborne diseases in Malaysia: A review. Food Control 2011; 22(6): 823-30.[http://dx.doi.org/10.1016/j.foodcont.2010.12.011]
[88] Kruse H, Kirkemo A-M, Handeland K. Wildlife as source of zoonotic infections. Emerg Infect Dis 2004; 10(12): 2067-72.[http://dx.doi.org/10.3201/eid1012.040707] [PMID: 15663840]

Endorsements



"Open access will revolutionize 21st century knowledge work and accelerate the diffusion of ideas and evidence that support just in time learning and the evolution of thinking in a number of disciplines."


Daniel Pesut
(Indiana University School of Nursing, USA)

"It is important that students and researchers from all over the world can have easy access to relevant, high-standard and timely scientific information. This is exactly what Open Access Journals provide and this is the reason why I support this endeavor."


Jacques Descotes
(Centre Antipoison-Centre de Pharmacovigilance, France)

"Publishing research articles is the key for future scientific progress. Open Access publishing is therefore of utmost importance for wider dissemination of information, and will help serving the best interest of the scientific community."


Patrice Talaga
(UCB S.A., Belgium)

"Open access journals are a novel concept in the medical literature. They offer accessible information to a wide variety of individuals, including physicians, medical students, clinical investigators, and the general public. They are an outstanding source of medical and scientific information."


Jeffrey M. Weinberg
(St. Luke's-Roosevelt Hospital Center, USA)

"Open access journals are extremely useful for graduate students, investigators and all other interested persons to read important scientific articles and subscribe scientific journals. Indeed, the research articles span a wide range of area and of high quality. This is specially a must for researchers belonging to institutions with limited library facility and funding to subscribe scientific journals."


Debomoy K. Lahiri
(Indiana University School of Medicine, USA)

"Open access journals represent a major break-through in publishing. They provide easy access to the latest research on a wide variety of issues. Relevant and timely articles are made available in a fraction of the time taken by more conventional publishers. Articles are of uniformly high quality and written by the world's leading authorities."


Robert Looney
(Naval Postgraduate School, USA)

"Open access journals have transformed the way scientific data is published and disseminated: particularly, whilst ensuring a high quality standard and transparency in the editorial process, they have increased the access to the scientific literature by those researchers that have limited library support or that are working on small budgets."


Richard Reithinger
(Westat, USA)

"Not only do open access journals greatly improve the access to high quality information for scientists in the developing world, it also provides extra exposure for our papers."


J. Ferwerda
(University of Oxford, UK)

"Open Access 'Chemistry' Journals allow the dissemination of knowledge at your finger tips without paying for the scientific content."


Sean L. Kitson
(Almac Sciences, Northern Ireland)

"In principle, all scientific journals should have open access, as should be science itself. Open access journals are very helpful for students, researchers and the general public including people from institutions which do not have library or cannot afford to subscribe scientific journals. The articles are high standard and cover a wide area."


Hubert Wolterbeek
(Delft University of Technology, The Netherlands)

"The widest possible diffusion of information is critical for the advancement of science. In this perspective, open access journals are instrumental in fostering researches and achievements."


Alessandro Laviano
(Sapienza - University of Rome, Italy)

"Open access journals are very useful for all scientists as they can have quick information in the different fields of science."


Philippe Hernigou
(Paris University, France)

"There are many scientists who can not afford the rather expensive subscriptions to scientific journals. Open access journals offer a good alternative for free access to good quality scientific information."


Fidel Toldrá
(Instituto de Agroquimica y Tecnologia de Alimentos, Spain)

"Open access journals have become a fundamental tool for students, researchers, patients and the general public. Many people from institutions which do not have library or cannot afford to subscribe scientific journals benefit of them on a daily basis. The articles are among the best and cover most scientific areas."


M. Bendandi
(University Clinic of Navarre, Spain)

"These journals provide researchers with a platform for rapid, open access scientific communication. The articles are of high quality and broad scope."


Peter Chiba
(University of Vienna, Austria)

"Open access journals are probably one of the most important contributions to promote and diffuse science worldwide."


Jaime Sampaio
(University of Trás-os-Montes e Alto Douro, Portugal)

"Open access journals make up a new and rather revolutionary way to scientific publication. This option opens several quite interesting possibilities to disseminate openly and freely new knowledge and even to facilitate interpersonal communication among scientists."


Eduardo A. Castro
(INIFTA, Argentina)

"Open access journals are freely available online throughout the world, for you to read, download, copy, distribute, and use. The articles published in the open access journals are high quality and cover a wide range of fields."


Kenji Hashimoto
(Chiba University, Japan)

"Open Access journals offer an innovative and efficient way of publication for academics and professionals in a wide range of disciplines. The papers published are of high quality after rigorous peer review and they are Indexed in: major international databases. I read Open Access journals to keep abreast of the recent development in my field of study."


Daniel Shek
(Chinese University of Hong Kong, Hong Kong)

"It is a modern trend for publishers to establish open access journals. Researchers, faculty members, and students will be greatly benefited by the new journals of Bentham Science Publishers Ltd. in this category."


Jih Ru Hwu
(National Central University, Taiwan)


Browse Contents



Webmaster Contact: info@benthamopen.net
Copyright © 2019 Bentham Open