Genetic characteristics of the whole genome sequences of coxsackievirus A6 strains in Jiangsu Province from 2013 to 2022 / 中国人兽共患病学报

This study explored the genetic characteristics of the whole genome sequences of coxsackie virus A6 strains in Jiangsu province from 2013 to 2022,and analyzed the genetic evolution of each coding region of the full-length genome.To in-vestigate why coxsackievirus A6 has replaced enterovirus A71 and coxsackievirus A16 as the most predominant etiological agent for HFMD in Jiangsu province,we selected 35 CVA6 isolates circulating in Jiangsu province during 2013-2022 for whole ge-nome sequence amplification and analysis.Sequence alignment,homology analysis,phylogenetic analysis and genetic recombi-nation were performed with the DNASTAR,MEGA7.0 and similarity plots 3.5.1 software packages.We analyzed the impor-tant amino acid sites of CV-A6 in the Pl region and 3D region.The nucleotide and amino acid similarities of 35 CV-A6 full-length genomes were 87.5％-99.6％ and 97.0％-99.8％,respectively,and the nucleotide and amino acid sequence identity with the CV-A6 prototype strain was 80.3％-81.0％ and 94.7％-95.3％,respectively.On the basis of phylogenetic analysis of VP1 region sequences,the 34 CV-A6 strains in this study belonged to the D3a genotype,and only one strain belonged to the D2 genotype.According to the phylo-genetic analysis of 3D region sequences,four recombinant forms(RFs),RF-A,RF-L,RF-K and RF-C,appeared primarily in 2013-2022 in Jiangsu province.Recombination analysis demonstrated that CVA6s,which was prevalent in Jiang-su from 2013 to 2022,had high similarity to the CVA6 prototype strain Gdula in the structured protein sequences.However,in the non-structured protein sequences and noncoding regions,similarities were higher among CVA6s and prototype strains of other EV-A types.Amino acid mutation site analysis showed that multiple amino acid sites in the Pl and 3D regions varied fre-quently with respect to the prototype strain Gdula.These differences might have resulted in small changes in the capsid struc-ture and potential receptor-binding sites.In conclusion,by analyzing the whole genome sequence of CV-A6,this study advances understanding of the gene recombination and genetic evolution relationship of CV-A6 in Jiangsu Province;in addition,it may explain possible reasons why CV-A6 has become the main pathogen of HFMD in recent years,and it provides basic data for the prevention and control of CV-A6.

Analysis on the secondary attack rates of SARS-CoV-2 Omicron variant and the associated factors / 中华预防医学杂志

Objective: To evaluate the secondary attack rates of the SARS-CoV-2 Omicron variant and the associated factors. Methods: A total of 328 primary cases and 40 146 close contacts of the SARS-CoV-2 Omicron variant routinely detected in local areas of Jiangsu Province from February to April 2022 were selected in this study, and those with positive nucleic acid test results during 7 days of centralized isolation medical observation were defined as secondary cases. The demographic information and clinical characteristics were collected, and the secondary attack rate (SAR) and the associated factors were analyzed by using a multivariate logistic regression model. Results: A total of 1 285 secondary cases of close contacts were reported from 328 primary cases, with a SAR of 3.2% (95%CI: 3.0%-3.4%). Among the 328 primary cases, males accounted for 61.9% (203 cases), with the median age (Q1, Q3) of 38.5 (27, 51) years old. Among the 1 285 secondary cases, males accounted for 59.1% (759 cases), with the median age (Q1, Q3) of 34 (17, 52) years old. The multivariate logistic regression model showed that the higher SAR was observed in the primary male cases (OR=1.632, 95%CI: 1.418-1.877), younger than 20 years old (OR=1.766, 95%CI: 1.506-2.072),≥60 years old (OR=1.869, 95%CI: 1.476-2.365), infected with the BA.2 strain branch (OR=2.906, 95%CI: 2.388-3.537), the confirmed common cases (OR=2.572, 95%CI: 2.036-3.249), and confirmed mild cases (OR=1.717, 95%CI: 1.486-1.985). Meanwhile, the higher SAR was observed in the close contacts younger than 20 years old (OR=2.604, 95%CI: 2.250-3.015),≥60 years old (OR=1.287, 95%CI: 1.052-1.573) and exposure for co-residence (OR=27.854, 95%CI: 23.470-33.057). Conclusion: The sex and age of the primary case of the Omicron variant, the branch of the infected strain, case severity of the primary case, as well as the age and contact mode of close contacts are the associated factors of SAR.

Analysis on the secondary attack rates of SARS-CoV-2 Omicron variant and the associated factors / 中华预防医学杂志

Objective: To evaluate the secondary attack rates of the SARS-CoV-2 Omicron variant and the associated factors. Methods: A total of 328 primary cases and 40 146 close contacts of the SARS-CoV-2 Omicron variant routinely detected in local areas of Jiangsu Province from February to April 2022 were selected in this study, and those with positive nucleic acid test results during 7 days of centralized isolation medical observation were defined as secondary cases. The demographic information and clinical characteristics were collected, and the secondary attack rate (SAR) and the associated factors were analyzed by using a multivariate logistic regression model. Results: A total of 1 285 secondary cases of close contacts were reported from 328 primary cases, with a SAR of 3.2% (95%CI: 3.0%-3.4%). Among the 328 primary cases, males accounted for 61.9% (203 cases), with the median age (Q1, Q3) of 38.5 (27, 51) years old. Among the 1 285 secondary cases, males accounted for 59.1% (759 cases), with the median age (Q1, Q3) of 34 (17, 52) years old. The multivariate logistic regression model showed that the higher SAR was observed in the primary male cases (OR=1.632, 95%CI: 1.418-1.877), younger than 20 years old (OR=1.766, 95%CI: 1.506-2.072),≥60 years old (OR=1.869, 95%CI: 1.476-2.365), infected with the BA.2 strain branch (OR=2.906, 95%CI: 2.388-3.537), the confirmed common cases (OR=2.572, 95%CI: 2.036-3.249), and confirmed mild cases (OR=1.717, 95%CI: 1.486-1.985). Meanwhile, the higher SAR was observed in the close contacts younger than 20 years old (OR=2.604, 95%CI: 2.250-3.015),≥60 years old (OR=1.287, 95%CI: 1.052-1.573) and exposure for co-residence (OR=27.854, 95%CI: 23.470-33.057). Conclusion: The sex and age of the primary case of the Omicron variant, the branch of the infected strain, case severity of the primary case, as well as the age and contact mode of close contacts are the associated factors of SAR.

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.

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>

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>

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>