Ten Yucatan miniature piglets were challenged with the human norovirus (NoV) GII.12/GII.3 CAU140599 strain and five piglets were used as negative controls. Stool, serum, and organs were collected and processed from two NoV-infected piglets and one negative piglet at 1, 2, 3, 5, and 7 days post-inoculation (dpi). NoV was detected in stool and serum samples by real-time RT-PCR. Mild diarrhea was observed at 1-3 dpi. Fecal shedding and viremia were detected intermittently at 1, 3, and 7 dpi. While interferon-α was significantly elevated at 2-3 dpi, interferon-γ was not changed. Immunohistochemistry demonstrated that the NoV capsid antigen was present in macrophages, lymphocytes, and dendritic cells of the stomach, intestines, lymph nodes, spleen, and tonsils. Intestinal epithelium did not exhibit a positive signal for NoV. In addition, negative-sense viral RNA was confirmed in immune cells by fluorescence in situ hybridization. Therefore, NoV might be associated with macrophages and lymphocytes in gastrointestinal tract and immune organs of experimentally infected miniature piglets.

infection by hepatitis e virus (HeV) via the oral route causes acute hepatitis. extra-hepatic manifestations of HeV infection may stem from various causes; however, its distribution in organs such as the liver, as well as the mechanisms underlying HeV-induced cell injury, remain unclear. the objective of this study was to determine the chronological distribution of HeV in various tissues of HeV-challenged miniature pigs and to investigate the mechanisms underlying HeV-induced cell death in the pancreas and liver. Virological and serological analyses were performed on blood and faecal samples. Histopathology of the liver and extra-hepatic tissues was analysed. cell death pathways and immune cell characterisation in inflammatory lesions were analysed using immunohistochemistry. The liver and pancreas displayed inflammation and cellular injury, and a large amount of HEV was observed in the lesions. The liver was infiltrated by T and natural killer cells. HEV was identified in all organs except the heart, and was associated with immune cells. Although the liver and the pancreas strongly expressed TNF-α and TRAIL, TUNEL assay results were negative. RIP3 and pMLKL were expressed in the pancreas. RIP3, but not pMLKL, was expressed in the liver. Pancreatitis induced in HeV-infected miniature pigs is associated with necroptosis. Worldwide, 14 million symptomatic infections, 5,200 stillbirths, and 300,000 deaths are attributed to hepatitis E virus (HEV) according to the World Health Organisation 1. While HEV infection is mostly associated with large epidemics in developing countries, autochthonous sporadic cases are on the rise in industrialised countries 2. In the UK, hepatitis E cases have been increasing since 2009, with an estimated annual infection rate of 200,000, which is largely attributed to the consumption of pork products 3,4. Clinical symptoms of HEV are mainly associated with acute hepatitis, fulminant hepatic failure, or chronic hepatitis in immunocompromised patients and the elderly. HEV genotype 1 and 2 infection is associated with high mortality rates (up to 25%) in pregnant women 5,6. Extra-hepatic lesions, including acute pancreatitis, renal failure, neurological diseases, haematological diseases, and the Guillain-Barre syndrome, are linked with HEV infection, cases of which are increasing. However, its pathogenesis is not well understood 7. Although several in vivo and in vitro models have been proposed for the purpose of cultivating HEV or mimicking HEV infection in laboratory animals, including rabbits, mice and rats, such in vivo models have not been successful in demonstrating the clinical symptoms of HEV infection 8-10. The use of non-human primates and conventional pig models is limited by high maintenance costs, difficulties in manipulation, and the need for many personnel 11,12. Miniature pigs have been experimentally infected with HEV genotypes 1, 3, and 4; they are susceptible to genotypes 3 and 4 13. Extra-hepatic manifestations have not yet been modelled because existing studies on miniature...

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Norovirus is the most common cause of acute gastroenteritis. Its pathogenesis is poorly understood owing to the difficulty of establishing viral infection in animal models. Here, postweaning gnotobiotic pigs were infected with human norovirus genogroup II genotype 4 (HuNoV GII.4) to investigate the pathogenesis and replication of the virus. Three groups of four pigs were infected with 1 × 10 5 , 1 × 10 6 , or 1 × 10 7 genomic equivalent (GE) copies of HuNoV GII.4. Four pigs were used as negative controls. Blood and rectal swab samples were collected after viral infection, and gross legions were examined after necropsy. Diarrhea was induced in 25% and 75% of pigs infected with 1 × 10 6 and 1 × 10 7 GE copies, respectively. Viral shedding was detected in 50%, 75%, and 50% of pigs infected with 1 × 10 5 , 1 × 10 6 , and 1 × 10 7 GE copies, respectively. Viremia was detected in 25% of pigs infected with either 1 × 10 6 or 1 × 10 7 GE copies. When gross lesions of gastroenteritis were investigated, the ileum walls of the infected pigs were thinner than those of the controls. Villi atrophy and inflammatory cell infiltration were identified in the ileum of each infected pig. Viral capsid was identified in the jejunum, ileum, colon, spleen, and mesenteric lymph node. Virus replication was newly verified in the spleen and mesenteric lymph nodes by detection of negative-sense viral RNA. In conclusion, HuNoV GII.4 could induce acute gastroenteritis and replicate in the extraintestinal lymphoid tissues in post-weaning gnotobiotic pigs. Therefore, such pigs would be a suitable animal model for studying the pathogenesis and replication of HuNoV.

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Equine parvovirus-hepatitis (EqPV-H) is a newly identified etiologic agent of Theiler’s disease (TD). We present a case of EqPV-H-related fulminant hepatitis in a 14-year-old thoroughbred mare in Korea. The mare had acute hepatopathy and gastrointestinal symptoms, with abnormal liver-related blood parameters. The horse was born in the USA and imported to Korea in 2017, with no history of administration of equine biological products after entry into Korea. The horse was diagnosed with EqPV-H-associated hepatitis after abdominal ultrasonography, laparotomy, and nested polymerase chain reaction (PCR) and in situ hybridization (ISH) assays. The serum, nasal swab, oral swab, and liver biopsy were positive for EqPV-H according to the PCR assay. Genetic analysis of the partial NS1 gene of EqPV-H showed a unique nucleotide substitution, distinct from that in previously deposited strains. EqPV-H DNA was found not only in hepatocytes but also in bile duct epithelium and Kupffer cells, particularly via ISH. To the best of our knowledge, this is the first case of EqPV-H-associated TD in Asia, providing the first clinical evidence for viral shedding from the mouth and nose, and identification of EqPV-H in the liver. This study contributes to a better understanding of the pathological features of EqPV-H-associated TD.

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This study aimed to investigate the prevalence of foodborne viruses in reservoirs (an important resource of irrigation water) and its correlation with environmental and weather factors. From May 2017 to November 2018, we visited ten reservoirs and a river in the Anseong region of South Korea and collected a total of 192 samples in accordance with the environment protection agency guidelines. We recorded the weather factors (temperature, humidity, and accumulated precipitation) and investigated the surrounding environment factors (livestock, fishing site, the catchment area of reservoirs, etc.). Our research results show that from the river and reservoirs, the detection rates of human norovirus GII, adenovirus, rotavirus, human norovirus GI, and astrovirus were 27.1, 10.4, 10.4, 4.16, and 3.1%, respectively. Their viral load ranged from −1.48 to 1.55 log10 genome copies/l. However, hepatitis A virus was not detected in any irrigation water sample. Although no sampling was performed in winter, foodborne viruses and male-specific coliphages were frequently found during spring (40.78%) and autumn (39.47%). Interestingly, the significant correlation between the accumulative precipitation and the number of detected norovirus and adenovirus was confirmed by linear regression analysis. Furthermore, when the accumulative precipitation ranged from 20 to 60 mm, it significantly affected the viral load and prevalence. Among the environmental factors, recreational facilities such as fishing sites and bungalow fishing spots were identified as contamination sources by correlation analysis. Our research results confirmed the correlations between environmental contamination factors in the reservoir and weather factors with the prevalence of foodborne viruses in the reservoir. These facilitates the assessment of potential foodborne virus contamination during crop irrigation. In addition, predictive models including environmental and weather factors should be developed for monitoring and controlling the safety of irrigation waters in reservoirs.