Prevalence and molecular characterization of porcine Picobirnavirus in piglets of North East Region of India

Picobirnaviruses (PBVs) have been recognized as one of the important causal viral agents of gastroenteritis in several animal species especially in young immunocompromised hosts. In this study, we report the prevalence and molecular epidemiology of porcine PBVs from North Eastern Hilly region of India. A total of 457 fecal samples from piglets were collected from local (n = 130) and cross (n = 327) breed piglets in different seasons for 2 years. All the samples were subjected to RNA-PAGE and RT-PCR analysis for detection of PBVs. A total of 4.59 and 11.15% samples were recorded as positive for PBVs by RNA-PAGE and RT-PCR, respectively. Rate of detection was higher from diarrhoeic animals (13.56%) compared to non-diarrhoeic (4.23%) animals. Higher prevalence rate was observed from unorganized farms (14.22%) compared to organized farms (8.0%) with slightly higher detection from cross breed (11.62%) compared to local breed (10.0%). Maximum cases of piglet diarrhea associated with PBVs were detected during summer (16.4%) and winter (14.39%) seasons compared to autumn (4.80%) and spring (6.45%). All the samples were positive for PBV genogroup I only. Based upon the sequence analysis, the isolates were unique and placed in separate clad and were not closely associated with any other Indian isolates of PBVs so far. Two isolates were closely related with one Chinese isolate recovered from sewage water. This is the first systematic study of prevalence of PBVs associated with piglet diarrhea.