Prevalence and seasonality of Salmonella isolations from commercial poultry in Zaria Nigeria: a five-year retrospective study

Background:Hepatitis E virus (HEV) infection inpigs is endemic n both developed and developing countries. Most of swine HEV solated so far belong to genotype 3 or 4. Several studies proposed hat genotype 3 and 4 are freely transmissible between human and wine. To assess the potential source of infection attributable to wine farming, we analyzed the prevalence of naturally infection igs in Thailand. Methods: During the period between May 2008 and June 2009, otal 532 pig feces were collected from pig farms in different age of igs, 1 to6month-old, sows, andboars,within6 regionsofThailand, entral, eastern,western, northern, upper north-eastern, and lower orth-eastern. The specimens were tested for HEV RNA by semiested RT-PCR using universal primers. All positive samples were irectly sequenced and 415 bp nucleotide sequences were comared with known HEV strains from GenBank. Results: Overall, 112 (21.1%) out of 532 fecal samples were etected HEV RNA. The prevalence of HEV infection of all areas nd groups ranged from 0.0-29.2% and 0.2-4.5%, respectively. The ighest prevalence was in the upper north-eastern area. However, f both parts of north-eastern were combined (21.6%), the highst prevalence was the western area with of the most pig farming one of Thailand (28.2%). Sequence analysis revealed that swine EV isolates from Thailand were clustered into genotype 3 of HEV. Conclusion: In this study, we showed the relatively high prevaence rate of HEV infection in swine in Thailand that seem to be ontrast with the rarity case of clinical hepatitis E in Thai populaion. HEV genotype 3 become a new risk and is considered as viral oonosis by reason of several reports of human cases worldwide, ncluding Thailand.