Major outbreaks of viral diseases remain a persistent and significant challenge in the pig industry. Among which gastrointestinal diseases are the most common in pigs, mainly the youngest. Notably, approximately half of the swine pathogens are viruses with zoonotic potential that can be transmitted to humans through direct or indirect contacts. Aim: This study investigates the prevalence of infections caused by astrovirus (AstV), group A rotavirus (RVA), calicivirus (norovirus NoV and sapovirus SaV), kobuvirus (PKoV) and coronavirus (CoV) in pigs. Sequence analysis was also conducted to gain deeper insights into the viral strains involved, aiming to identify which viruses are currently circulating in pig farms and to determine whether any changes have occurred over the past 10 years, since we carried out a similar study in the same geographical area. Methods: Utilizing a cross-sectional study,102 pooled fecal samples from fatteners were collected on 5 pig farms, 20 pooled fecal samples each except one farm, of fattener and breeding farm types across Italy. Total RNA was extracted from a 10% (w/v) fecal suspension, obtained from 102 pooled fecal samples randomly collected from the pen floor. The RNA was subjected to either reverse transcription PCR or nested RT-PCR using primers specifically annealing to conserved regions of the investigated viruses. DNA amplicons obtained with expected size were subjected to Sanger sequencing (Eurofins Genomics). Phylogenetic trees were drawn using the MEGA X software. Results: Overall, the analyzed viruses were very common, even in animals that appeared asymptomatic. None of the five farms tested negative for the investigated viruses. Specifically, rotavirus and astrovirus were the most frequently detected across all five farms, followed by kobuvirus, which was found in four farms, and calicivirus, which was detected in only two. Due to the use of pooled samples, it was not possible to establish the prevalence but based on the number of positive pools for each pathogen within farm we could observe a wider circulation of astrovirus and kobuvirus, showing a percentage of positive pooled fecal samples between 45% and 85%. Whereas it decreases for rotavirus detection to 10-35%. Sequencing is still ongoing. So far, the presence of Astrovirus types 2 and 4 has been confirmed, with the detection of GII.11, a typical swine Norovirus, as well as the Sapovirus GVIII. Rotavirus A, the G2 G5 and G11 genotypes were detected. Conclusion: Pigs serve as hosts for many enteric viruses, some of which exhibit a high genetic similarity to human strains and could belong to the same cluster of human strains, posing concerns about their potential to cause emerging zoonotic infections. These viruses deserves further investigation to assess their role on general health status of pigs, being frequently present in symptomatic and asymptomatic animals mostly in co-infection. The persistence of these viruses in pig populations highlights the need for continued surveillance to understand better their epidemiology and impact on both animal and public health.
Di Bartolo, I., Ostanello, F., Settanni, C., Ranucci, D., De Sabato, L., Ianiro, G., et al. (2025). Circulation of zoonotic viruses in 5 pig farms in Nothern italy.
Circulation of zoonotic viruses in 5 pig farms in Nothern italy
Ostanello F.;
2025
Abstract
Major outbreaks of viral diseases remain a persistent and significant challenge in the pig industry. Among which gastrointestinal diseases are the most common in pigs, mainly the youngest. Notably, approximately half of the swine pathogens are viruses with zoonotic potential that can be transmitted to humans through direct or indirect contacts. Aim: This study investigates the prevalence of infections caused by astrovirus (AstV), group A rotavirus (RVA), calicivirus (norovirus NoV and sapovirus SaV), kobuvirus (PKoV) and coronavirus (CoV) in pigs. Sequence analysis was also conducted to gain deeper insights into the viral strains involved, aiming to identify which viruses are currently circulating in pig farms and to determine whether any changes have occurred over the past 10 years, since we carried out a similar study in the same geographical area. Methods: Utilizing a cross-sectional study,102 pooled fecal samples from fatteners were collected on 5 pig farms, 20 pooled fecal samples each except one farm, of fattener and breeding farm types across Italy. Total RNA was extracted from a 10% (w/v) fecal suspension, obtained from 102 pooled fecal samples randomly collected from the pen floor. The RNA was subjected to either reverse transcription PCR or nested RT-PCR using primers specifically annealing to conserved regions of the investigated viruses. DNA amplicons obtained with expected size were subjected to Sanger sequencing (Eurofins Genomics). Phylogenetic trees were drawn using the MEGA X software. Results: Overall, the analyzed viruses were very common, even in animals that appeared asymptomatic. None of the five farms tested negative for the investigated viruses. Specifically, rotavirus and astrovirus were the most frequently detected across all five farms, followed by kobuvirus, which was found in four farms, and calicivirus, which was detected in only two. Due to the use of pooled samples, it was not possible to establish the prevalence but based on the number of positive pools for each pathogen within farm we could observe a wider circulation of astrovirus and kobuvirus, showing a percentage of positive pooled fecal samples between 45% and 85%. Whereas it decreases for rotavirus detection to 10-35%. Sequencing is still ongoing. So far, the presence of Astrovirus types 2 and 4 has been confirmed, with the detection of GII.11, a typical swine Norovirus, as well as the Sapovirus GVIII. Rotavirus A, the G2 G5 and G11 genotypes were detected. Conclusion: Pigs serve as hosts for many enteric viruses, some of which exhibit a high genetic similarity to human strains and could belong to the same cluster of human strains, posing concerns about their potential to cause emerging zoonotic infections. These viruses deserves further investigation to assess their role on general health status of pigs, being frequently present in symptomatic and asymptomatic animals mostly in co-infection. The persistence of these viruses in pig populations highlights the need for continued surveillance to understand better their epidemiology and impact on both animal and public health.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
