Abstract
A recent survey of pigs in Dong Thap province, Vietnam identified a high frequency of enterovirus species G (EV-G) infection (144/198; 72.7%). Amongst these was a plethora of EV-G types (EV-G1, EV-G6 and four new types EV-G8-EV-G11). To better characterize the genetic diversity of EV-G and investigate the possible existence of further circulating types, we performed a larger-scale study on 484 pig and 45 farm-bred boar faecal samples collected in 2012 and 2014, respectively. All samples from the previous and current studies were also screened for kobuviruses. The overall EV infection frequency remained extremely high (395/484; 81.6%), but with comparable detection rates and viral loads between healthy and diarrhoeic pigs; this contrasted with less frequent detection of EV-G in boars (4/45; 8.9%). EV was most frequently detected in pigs ≤ 14 weeks old (∼ 95%) and declined in older pigs. Infections with EV-G1 and EV-G6 were most frequent, whilst less commonly detected types included EV-G3, EV-G4 and EV-G8-EV-G11, and five new types (EV-G12-EV-G16). In contrast, kobuvirus infection frequency was significantly higher in diarrhoeic pigs (40.9 versus 27.6%; P = 0.01). Kobuviruses also showed contrasting epizootiologies and age associations; a higher prevalence was found in boars (42%) compared with domestic pigs (29%), with the highest infection frequency amongst pigs >52 weeks old. Although genetically diverse, all kobuviruses identified belonged to the species Aichivirus C. In summary, this study confirms infection with EV-G was endemic in Vietnamese domestic pigs and exhibits high genetic diversity and extensive inter-type recombination.
Highlights
Porcine enteroviruses (PEVs) are members of the family Picornaviridae and originally consisted of 13 typesThe GenBank/EMBL/DDBJ accession numbers for the sequences obtained in this study are KT265880–KT266194
PEV-9 and PEV10 were classified as EV-G1 and EV-G2 serotypes in enterovirus G, with the subsequently characterized enterovirus species G (EV-G) types EV-G3–EV-G6 reported in single publications from Hungary and South Korea
Our molecular characterization of EVs in a small number of PCR-positive faecal samples from domestic pigs identified a further four types (EV-G8–EV-11) within this species. The presence of such a large amount of genetic diversity within such a modest number of samples suggests that the full range of EV-G types in this virus species has yet to be fully characterized (Van Dung et al, 2014)
Summary
Porcine enteroviruses (PEVs) are members of the family Picornaviridae and originally consisted of 13 typesThe GenBank/EMBL/DDBJ accession numbers for the sequences obtained in this study are KT265880–KT266194. Our molecular characterization of EVs in a small number of PCR-positive faecal samples from domestic pigs identified a further four types (EV-G8–EV-11) within this species. Infections with EV-G have not been linked to any enteric or other disease presentations (Knowles, 2006) except for skin lesions (Knowles, 1988) and flaccid paralysis in an experimental infection of pigs in China (Yang et al, 2013) Viruses in this species have been reported from both healthy and diarrhoeic pigs with no statistically significant difference in infection rates between the two groups (Van Dung et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
