Molecular characteristics of acute gastroenteritis outbreaks caused by norovirus, in Jiangsu province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study both the epidemiologic and molecular characteristics of outbreaks caused by norovirus (NoV) with its variants, in Jiangsu.</p><p><b>METHODS</b>67 specimens from seven gastroenteritis outbreaks were collected from October 2012 to March 2013 in Jiangsu. NoV gene group was detected by Real-Time RT-PCR. NoV portions of RdRp gene and VP1 gene were amplified under RT-PCR.</p><p><b>RESULTS</b>Seven gastroenteritis outbreaks were caused by NoV. Among all the fecal specimens,45 (67.2%) showed positive to NoV G II. Study on the genotype was conducted through analyzing the nucleotide sequence of RdRp gene. Based on the RdRp region, 7 strains appeared to be G II, with 3 and 38 strains belonged to G II.4--Sydney variants. Results from phylogenetic analysis confirmed that 38 variants shared 99% identity with G II.4--Sydney. We also amplified the VP1 genes from 6 variants and comparing with 9 epidemic strains on the sequence amino acid sequence. All the strains showed mutation in amino acid sequence at some key sites which were closely related to the forming of neutralizing epitopes.</p><p><b>CONCLUSION</b>The short interval periods between all 7 NoV outbreaks with identical viral strain indicated the emergence of a new NoV variant in Jiangsu province,that had caused a number of epidemics abroad. Results from our study suggested that the development of monitoring programs on this novel G II.4--Sydney variant should be a part of the NoV surveillance in Jiangsu province or even in the country.</p>

Molecular features of human bocavirus from infantile diarrhea in Suzhou area, Jiangsu province in 2010-2011 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the status of human bocavirus and to identify its epidemiological characteristics as well as genotype distribution in patients with infantile viral diarrhea in Suzhou, Jiangsu province.</p><p><b>METHODS</b>832 fecal specimens from patients with infantile virus diarrhea cases were collected from Suzhou Children's Hospital in 2010-2011. Human bocavirus were detected by Real-Time RT-PCR, and genotype were determined by sequence analysis.</p><p><b>RESULTS</b>Among all the fecal specimens, 51 (6.1%) cases were positive for human bocavirus. The peak season of rotavirus infection was between July and September. Of all the episodes on rotavirus diarrhea, 96% occurred before 2 years of age, with peaks in children with 7-12 months of age. Data from Nucleotide Sequence analysis showed that among 28 samples that carrying HBoV-1, 5 strains belonged to HBoV-2, HBoV type 3 but type 4 were absent.</p><p><b>CONCLUSION</b>Human bocavirus were detected from fecal specimens of infantile virus diarrhea in Suzhou, with genotype HBoV-1 as the major strain. HBoV-2 genotype was also found.</p>

Serologic survey on pandemic influenza A (H1N1) virus among aged ≥3 years population from Jiangsu province in 2009, China / 中华流行病学杂志

Objective To understand the antibody levels against pandemic influenza A (H1N1) virus (2009 H1N1 ) among aged ≥3 years population in 2009, from Jiangsu province, and to describe the distribution of 2009 H1N1. Methods Serum specimens were collected from natural populations at four different periods in Jiangsu, and tested with hernagglutination-inhibition (HI)assays. Rates of protective antibody against 2009 H1N1 and Geometric mean titers (GMTs)were estimated. Results The rates of protective antibody against 2009 H1N1 rose with the and November, 2009. There were no significant differences on the rates of protective antibody between males and females at four different cross-sectional periods (P＞0.05), and no significant differences on GMTs were observed at different periods except for November 2009. Significant differences on rates of protective antibody and GMTs among various age groups were observed at four different periods (P＜0.05), and similar results were observed among different periods in various age groups (P＜0.05). There were significant differences on rates of protective antibody and GMTs among different areas (P＜0.05). Conclusion The 2009 H1N1 strain had been widely spread out in Jiangsu province since July 2009. People aged 12-17 years became the major victims after August. As of November 2009, the rate of protective antibody against 2009 H1N1 was still low, predicting that the epidemic might continue to exist for a certain period of time.