Occurrence of antibodies against Maedi-Visna in Santa Inês sheep in the State of Sergipe, Brazil

Small Ruminant Lentiviruses (SRLV) are infectious diseases of viral etiology caused by retroviruses, characterized for being a slowly progressive degenerative disease. The aim of this study was to determine the occcurrence of antibodies against lentivirus in the flock of Santa Inês sheep in Sergipe, Brazil. A minimum number of samples was analyzed by the Astudillo calculation, with an expected prevalence (p) of 10%, error rate (α) of 20% and confidence level of 95% (g = 1.96) obtaining the minimum number of samples (n) of 861. Finally, 941 serum samples were collected, derived from 54 properties and 19 municipalities distributed in three regions of the State, and the number of collected samples was proportional to the sheep flock of each municipality. The serum was placed at -20°C until the Agar Gel Immunodiffusion test (AGID), and results considered as positive or suspicious in AGID were assessed by the Western blotting technique. Out of sampled animals, 194 (20.62%) were male and 747 (79.38%) were female. From the stratification by age, 300 were young sheep (31.88%), aged between six months and one year old, 308 (32.73%) were young adults, aged between 1 and 3 years old, and 333 (35.39%) were estimated to be older than three years old. Results showed that antibodies against the Maedi-Visna virus in the sheep flock occcurred in the State of Sergipe at low frequency (0.11%). Thus, the occcurrence of Maedi-Visna infection in sheep in the State of Sergipe is reported, and emphasizes the participation of the transit of animals in the epidemiology of the disease.

epidemiology; SRLV; Ovis aries; retroviruses

Instituto Biológico Av. Conselheiro Rodrigues Alves, 1252 - Vila Mariana - São Paulo - SP, 04014-002 - São Paulo - SP - Brazil
E-mail: arquivos@biologico.sp.gov.br