Picornavirus Salivirus/Klassevirus in Children with Diarrhea, China

To learn more about salivirus/klassevirus, we tested feces of children with diarrhea in China during 2008–2009. We isolated the virus from 9/216 diarrhea samples and 0/96 control samples. The nearly full polyprotein of 1 isolate, SH1, showed 95% identity with a salivirus from Nigeria, indicating widespread distribution and association with diarrhea.

Studies have documented an association between Aichi viruses and gastroenteritis (5,6). Recent studies have documented human infections with the salivirus/klassevirusrelated Aichi virus (7-9) that were associated with diarrhea (9). The previously unknown picornavirus klassevirus has recently been recently detected in fecal samples from persons with diarrhea in the United States and Australia and in sewage in Spain (7,8). Closely related saliviruses have been identifi ed in fecal samples from persons in Nigeria, Tunisia, and Nepal and have been statistically associated with diarrhea in Nepal (9).
Klassevirus/salivirus is genomically organized similar to other picornaviruses and most closely related to Aichi virus in the genus Kobuvirus (5-7). The family Picornaviridae is highly diverse and contains small, nonenveloped viruses with a single-stranded positive-sense RNA genome that encodes a single polyprotein; it consists of 12 genera and 2 possibly new genera (7), a subset of which can infect and cause disease in humans.
To our knowledge, there have been no reports of infection with this virus in the People's Republic of China. Therefore, to extend these initial fi ndings, we tested for this newly characterized virus in fecal samples from children with diarrhea in China and sequenced the nearly full genome of 1 isolate, SH1.

The Study
During April 2008-March 2009, a total of 216 fecal samples were collected from children, 2-6 years of age, who were hospitalized with diarrhea in Shanghai Children's Hospital, China. A total of 96 children, 3-5 years of age, from 2 childcare centers in Shanghai City were included as healthy controls.
Samples were suspended to 10% (wt/vol) in phosphate-buffered saline (0.01 M, pH 7.4), and total RNA was extracted from 200 μL of the suspension by using TRIZOL reagent (Invitrogen, Carlsbad, CA, USA). Viral RNA was dissolved in 30 μL RNase-free water and stored at -80°C.
The complete genomic sequence of strain SH1 was then determined by using 10 sets of specifi c oligo-  (Figure). The nearly full genome of SH1 has been submitted to GenBank under accession no. GU245894. The 9 partial 414-bp sequences of salivirus/klassevirus are deposited in GenBank under accession nos. GU376738-GU376746.

Conclusions
Our fi nding of salivirus/klassevirus in fecal samples of children with diarrhea in China is consistent with Li et al.'s report of this virus' association with diarrhea (9). This fi nding, plus the identity with the Nigeria reference strain, support widespread distribution of this newly characterized virus species and its association with diarrhea.