Equine Granulocytic Anaplasmosis, A Neglected Disease: Risk Factors Associated with Prevalence of Antibodies in Equines
Francisco Carlos Rodrigues de Oliveira1, Marcia Farias Rolim1, Samira Salim Mello Gallo1, Célia Rachel Quirino2, Nicole Brand Ederli3, *
1 Laboratório de Sanidade Animal, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil, 28013-602
2 Laboratório de Reprodução e Melhoramento Genético Animal, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil, 28013-602
3 Instituto do Noroeste Fluminense de Educação Superior (INFES), Universidade Federal Fluminense (UFF), Av. João Jasbick, s/n, Aeroporto, Santo Antônio de Pádua, RJ, Brazil, 28.470-000
Anaplasma phagocytophilum, a tick-borne bacterium that causes granulocytic anaplasmosis, is a neglected pathogen in Brazil, and is diagnosed in several species of domestic and wild animals as well as in humans.
This study aimed to investigate the prevalence of anti-A. phagocytophilum antibodies in Equidae from the state of Rio de Janeiro and to identify possible risk factors for infection.
Materials and Methods:
A total of 612 blood samples were collected from horses from 15 municipalities within the state. Moreover, an epidemiological questionnaire was administered to evaluate aspects related to seroreaction, taking into account the spatial distribution (properties, municipalities, and mesoregions), management practices, signs of disease, and the individual state of the animals. For the diagnosis, indirect immunofluorescence was performed.
In the present study, 124 (20.26%), out of a total of 612, animals with anti-A. phagocytophilum IgG antibodies at titers of 1:80 were detected. Multivariate logistic regression analysis showed that the presence of the infection at the property (P <0.0001) and the origin (P = 0.0095) of the horse were the true risk factors for infection in the state of Rio de Janeiro.
This allows to infer that the bacterium is distributed in all mesoregions of the state of Rio de Janeiro and that animals from other states can introduce the infection and make a property a focus of disease; it can also be inferred that these properties are important in the maintenance of the disease and the permanence of bacteria circulating in horses. It is also noteworthy that this was the first identification of mules as hosts of A. phagocytophilum infection.
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* Address correspondence to this author at the 3Instituto do Noroeste Fluminense de Educação Superior (INFES), Universidade Federal Fluminense (UFF), Av. João Jasbick, s/n, Aeroporto, Santo Antônio de Pádua, RJ, Brazil; Tel: +55 (22) 27397359; E- mail: firstname.lastname@example.org