Prevalence of hepatitis E virus and porcine caliciviruses in pig farms of Guizhou province, China

Backgroud: hepatitis e virus (hev) and caliciviruses are enteric pathogens of humans and animals, and pigs have been considered an important reservoir of these viruses.objectives: the aim of this study is to determine the infection rates of hev and caliciviruses (sapovirus [sav] and norovirus [nov]) in different age groups of pigs in guizhou province, china, and characterize the strains that are prevalent in this mountainous area.materials and methods: a total of 209 stool samples from healthy pigs of different ages were collected from 6 pig farms in guizhou province from may to june 2009 and tested for hev, sav, and nov by reverse-transcription polymerase chain reaction (rt-pcr).results: the overall prevalence of porcine hev and porcine sav was 6.7% (15/209) and 1.0% (2/209), respectively. no nov was detected. the prevalence rates of porcine hev infection were 15.4% in piglets aged < 1 mon (4/26), 6.8% in piglets aged between 1 and 4 mon (3/44), 12.5% in piglets aged ? 4 mon (6/48), and 1.1% in sows aged between 6 and 14 mon (2/91). porcine sav was detected only in piglets (7.7%, 2/26). all 10 hev isolates belonged to genotype 4, clustering with a human hev strain (af103940) from an adjacent province.conclusions: this is the first report on the existence of porcine sav in swine in guizhou province, china. the clustering of the porcine hev isolates with a human strain suggests cross-species transmission between swine and humans in this area.