Avaliação clínico-laboratorial de equídeos naturalmente infectados pelo equine infectious anemia vírus

Abstract

EIA is a severe infectious disease of great importance for equine breeding. It is caused by the Equine infectious anemia virus (EIAV), which belongs to the Retroviridae family and Lentivirus genus. Infected animals can become lifelong asymptomatic carriers and potential transmitters of EIAV. The disease is on the list of the World Organization for Animal Health among the 11 notifiable diseases of horses, as it is a disease with high morbidity, no treatment, and no vaccine which causes health and economic obstacles to equine breeding, as well as in almost in all countries some regulations require the euthanasia of the infected animal as a form of EIA control. The pathogenesis of the disease is highly variable, ranging from an unapparent infection to a deadly one. However, most animals infected by the virus are asymptomatic carriers, and clinical diagnosis is impossible, so laboratory diagnosis plays a decisive role in controlling and preventing the disease. The objective of this study was to evaluate and monitor the clinical course of EIAV infection in naturally infected horses, in addition to performing the detection and molecular characterization of EIAV circulating in Northeastern Brazil. We emphasize that the Brazilian Northeast concentrates the most significant number of donkeys in the country, so we also sought to conduct epidemiological surveys and clinical evaluations in this species. The study was carried out in two different populations, one in a farm that shelters abandoned and seized animals on roads throughout the state of Ceará, where 127 animals were evaluated (124 donkeys and 3 horses), and in Vila de Jericoacoara, located in the Jericoacoara National Park (PARNA Jericoacoara), where 112 animals (104 horses and 8 mules) used in ecological equestrian tourism were evaluated. Of the 124 donkeys, only 0,81% (1/124) were positive in the AGID, 22% (27/124) in the gp90 ELISA and 10,6% (13/124) in the p26 ELISA. Of the three horses on the farm, all were positive in AGID and p26 ELISA, but only two (2/3) were positive in gp90 ELISA. From these animals, six EIAV nucleotide sequences were obtained. Furthermore, it was possible to carry out evaluations to monitor and describe the clinical and laboratory evolution of a donkey naturally infected with EIAV, proving that the species present symptoms similar to those described in horses. Of the 112 horses, 1,6% (13/112) were positive on AGID, 25,9% (29/112) on the p26 ELISA and 36,6% (41/112) on the gp90 ELISA. With the hematological evaluations of this population, statistical analyses confirmed an association between changes in GGT levels and the presence of EIAV infection. from Japan backed by a significant bootstrap value. All results were sent to the institutions responsible for animal health in Ceará (MAPA and ADAGRI), where contingency plans were implemented for the main equine diseases, so that the data generated in this study can help guide EIA control policies.