Objective Studying acute viral diarrhoea in paediatric patients in Chongqing may provide basic data and a theoretical foundation for formulating a strategy to prevent and control viral diarrhoea.
Methods Diarrhoea specimens in 384 infants with suspected viral diarrhoea between January 2012 and December 2012 in Chongqing region were collected. Colloidal Gold was used for the detection of group A rotavirus (RV). RT-PCR was used for nucleic acid detection of norovirus (NV), sapovirus (SV), and astrovirus (ASV). PCR was adopted for nucleic acid detection of human adenovirus (HAdV). In addition, potential NV recombinant strains need to be identified.
Results Diarrhoea virus-positive rates were 44.27% (170/384, RV), 21.88% (84/384, NV), 10.16% (39/384, HAdV), 7.81% (30/384, ASV), and 6.77% (26/384, SV), respectively. Mixed infection accounted for 16.15% (62/384) of cases. Sequencing analyses showed that GII.4, GI, ASV-1, and Ad41 genotypes were the predominant epidemic strains of NV, SV, ASV, and HAdV. A total of 5 NV GII recombinant types were identified in this study, GII.e/GII.4 Sydney 2012, GII.7/GII.6, GII.22/GII.5, GII.12/GII.3 and GII.16/GII.13.
Conclusions RV, NV, SV, HAdV and ASV have been found to be the 5 major pathogens causing infantile viral diarrhoea in Chongqing, responsible 73.70% of the total viral diarrhoea cases. Among them, RV is the major pathogen, followed by NV.
After August 2012, the NV predominant strains of GII.4 2006 gradually changed to the recombination strains of GII.e/GII.4 Sydney 2012,and this is the first report of the detection of GII.22/GII.5 and GII.16/GII.13 novel recombinant norovirus.