Drug resistance and molecular characteration of hemagglutinin and neuraminidase for influenza A H3N2 viruses / 医学研究生学报

Objective　To analyze the variations and drug resistance of influenza A (H3N2) viruses in Jiangsu Province in 2017, and provide evidence for prevention and control strategies on influenza.　Methods　Reverse transcription polymerase chain reaction (RT-PCR) was used for the sequencing of H3N2 subtype influenza strains. The influenza reference sequences were obtained from the global shared influenza site GISAID. The sequence alignment and phylogenetic analysis were performed using MAGE7.0 software. Viral resistance was analyzed by a neuraminidase inhibition assay.　Results　The H3N2 subtype influenza isolates and vaccine strains belonged to the 3C.2a branch of the H3 subtype. Some of the strains showed amino acid mutations on the immune-related sites named N121K, T135K and N171K. The isolates were sensitive to the flu drugs oseltamivir and zanamivir.　Conclusion　The H3N2 epidemic strains in Jiangsu have genetic recombination within subtypes and are still sensitive to neuraminidase inhibitors. As the H3N2 influenza virus mutations continue, a close monitoring of the viral genetic evolution and the drug resistant genes should be guaranteed.

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>

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>

A cross-sectional survey on the prevalence of Brucellosis among workers in Jiangsu province, 2012 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the status of infection and risk factors on Brucellosis among workers in Jiangsu province so as to provide related preventive and control measures.</p><p><b>METHODS</b>A cross-sectional survey was conducted on 238 workers at three butcheries, one trading market and one stockyard. Related risk factors on the different exposures to the disease were also analyzed.</p><p><b>RESULTS</b>50 workers were identified to have had the infection, with a infection rate as 21% (50/238). No significant differences in gender, age, working length and occupations were found. Jobs as slaughtering (RR = 1.80, 95%CI:1.1-3.1), particular on bleeding (RR = 1.90, 95%CI:1.1-3.3) were risk factors. Habit as hand-washing before eating was a protective factor (RR = 0.25, 95% CI: 0.14-0.44).</p><p><b>CONCLUSION</b>Workers from butcheries, trading markets and stockyards were seriously infected with Brucellosis in Jiangsu province and related. Control measures and education should be implemented to the workers in that trade.</p>

The application of time series analysis in predicting the influenza incidence and early warning / 中华预防医学杂志

<p><b>OBJECTIVE</b>This research aimed to explore the application of ARIMA model of time series analysis in predicting influenza incidence and early warning in Jiangsu province and to provide scientific evidence for the prevention and control of influenza epidemic.</p><p><b>METHODS</b>The database was created based on the data collected from monitoring sites in Jiangsu province from October 2005 to February 2010. The ARIMA model was constructed based on the number of weekly influenza-like illness (ILI) cases. Then the achieved ARIMA model was used to predict the number of influenza-like illness cases of March and April in 2010.</p><p><b>RESULTS</b>The ARIMA model of the influenza-like illness cases was (1 + 0.785B(2))(1-B) ln X(t) = (1 + 0.622B(2))ε(t). Here B stands for back shift operator, t stands for time, X(t) stands for the number of weekly ILI cases and ε(t) stands for random error. The residual error with 16 lags was white noise and the Ljung-Box test statistic for the model was 5.087, giving a P-value of 0.995. The model fitted the data well. True values of influenza-like illness cases from March 2010 to April 2010 were within 95%CI of predicted values obtained from present model.</p><p><b>CONCLUSION</b>The ARIMA model fits the trend of influenza-like illness in Jiangsu province.</p>