Association between gestational diabetes mellitus and preterm birth subtypes / 中华流行病学杂志

Objective: To investigate the association between gestational diabetes mellitus (GDM) and preterm birth subtypes. Methods: Based on the cohort of pregnant women in Anqing Prefectural Hospital, the pregnant women who received prenatal screening in the first or second trimesters were recruited into baseline cohorts; and followed up for them was conducted until delivery, and the information about their pregnancy status and outcomes were obtained through electronic medical record system and questionnaire surveys. The log-binomial regression model was used to explore the association between GDM and preterm birth [iatrogenic preterm birth, spontaneous preterm birth (preterm premature rupture of membranes and preterm labor)]. For multiple confounding factors, the propensity score correction model was used to compute the adjusted association. Results: Among the 2 031 pregnant women with a singleton delivery, the incidence of GDM and preterm birth were 10.0% (204 cases) and 4.4% (90 cases) respectively. The proportions of iatrogenic preterm birth and spontaneous preterm birth in the GDM group (n=204) were 1.5% and 5.9% respectively, while the proportions in non-GDM group (n=1 827) were 0.9% and 3.2% respectively, and the difference in the proportion of spontaneous preterm birth between the two groups was significant (P=0.048). Subtypes of spontaneous preterm were further analyzed, and the results showed that the proportions of preterm premature rupture of membranes and preterm labor in the GDM group were 4.9% and 1.0% respectively, while the proportions in the non-GDM group were 2.1% and 1.1% respectively. It showed that the risk of preterm premature rupture of membranes in GDM pregnant women was 2.34 times (aRR=2.34, 95%CI: 1.16-4.69) higher than that in non-GDM pregnant women. Conclusions: Our results showed that GDM might increase the risk of preterm premature rupture of membranes. No significant increase in the proportion of preterm labor in pregnant women with GDM was found.

Study on the prevalence and genotype of hepatitis E virus among commercial swine population in Eastern and Southern China / 中华流行病学杂志

Objective To determine the prevalence and genotype of hepatitis E virus (HEV)among commercial swine population in Eastern and Southern China. Methods Six hundred specimens of swine bile collected from 5 slaughterhouses in Eastern and Southern China from 2007 to 2009 were tested for HEV RNA using nested RT-PCR. PCR products were sequenced for phylogenetic analysis. Results Forty-seven out of the 600 samples (7.83%) were positive for HEV RNA. Based on the 150 nt fragment within HEV ORF2, data from phylogenetic analysis revealed that all the 47 HEV isolates were identified to be genotype Ⅳ, sharing 75.0%-83.4%, 75.0%-84.6%, 71.9%-80.7% and 88.1%-91.5% nucleotide identities with prototype Ⅰ,Ⅱ,Ⅲ and Ⅳ HEV strains respectively while majority of the isolates clustered within their respective isolation sites. Conclusion HEV was widespread in commercial swine population in Eastern and Southern China that raised a serious concern about the safety regarding the consumption of pork products.

Phylogenetic analysis of hepatitis E virus strains isolated from both human and swine in Anqing City / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the genotype and phylogenetic characteristics of hepatitis E virus (HEV) strains isolated from the human and swine in Anqing City.</p><p><b>METHODS</b>Twenty seven sera from sporadic hepatitis E patients and 400 commercial swine bile samples were collected in Anqing City. According to the collection time, the bile samples were equally divided into 4 groups which were named group A, B, C and D respectively. Nested reverse transcription polymerase chain reaction (RT-PCR) and DNA sequencing technology were performed to obtain the DNA sequences of HEV RNA Open Reading Frame 2 (ORF2) (150 nt) for all the serum and bile samples. The sample sequences and prototype sequences from the GenBank were aligned and their nucleotide sequence identities were calculated. A phylogenetic tree constructed according to the Bayesian inference method was used to analyze the genotype and phylogenetic relationship between the human and swine HEV strains isolated in Anqing City.</p><p><b>RESULTS</b>The male-to-female sex ratio of the patients was 2.86:1 and the average age was 56.78 years old. Sixteen out of 27 serum (59.26%) samples were HEV RNA positive. Human HEV strains isolated in Anqing City shared 74.75% - 82.99%, 75.26% - 83.64%, 72.77% - 80.57% and 88.03%-91.63% nucleotide sequence identities with prototype I, II, III and IV HEV strains respectively. HEV RNA was detected in 22 out of 400 bile samples (5.5%). The swine HEV detection rates for group A, B, C and D were 7.00%, 3.00%, 9.00% and 3.00% respectively, showing no significant difference among these groups (χ(2) = 5.20, P = 0.16). Swine HEV strains isolated in Anqing City shared 75.24% - 83.42%, 75.93% - 84.19%, 72.86% - 80.64% and 88.15% - 91.79% nucleotide sequence identities with prototype I, II, III and IV HEV strains respectively. Phylogenetic analysis revealed that all the HEV strains isolated from both the human and swine belonged to genotype IV and scattered in evolutionary branches without significant species aggregation.</p><p><b>CONCLUSION</b>It's suggested that genotype IV HEV was the dominant genotype among the human and swine in Anqing City and probably transmitted between them in this area.</p>

Phylogenetic analysis of sporadic hepatitis E virus in Eastern China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand phylogenetic characteristics of sporadic hepatitis E virus (HEV) in eastern China.</p><p><b>METHODS</b>Four hundred and thirteen sera were collected from sporadic hepatitis E cases in 14 second- or first-class hospitals in Eastern China from 2005 to 2008 and detected with a nested RT-PCR assay. Partial nucleotide sequences of the HEV isolates were determined for phylogenetic analysis with prototype sequences in the GenBank.</p><p><b>RESULTS</b>The male-to-female sex ratio of the patients was 1.75:1 with 61.5% of them aged 40 - 69 years old. HEV RNA was detected in 140 out of 413(34%)serum samples. Phylogenetic analysis revealed that all the 140 HEV isolates belonged to genotype IV, sharing 77.9% - 88.3%, 80.8% - 90.6%, 73.4% - 85.2% and 91.0% - 95.4% nucleotide sequence identities with prototype I, II, III and IV HEV isolates respectively.</p><p><b>CONCLUSION</b>It was evident that genotype IV HEV served as the main causative agent of sporadic HEV infection in Eastern China. However the viral origin and evolution needs further clarification.</p>

Seasonal pattern and phylogenetic analysis with human isolates of genotype-IV hepatitis E virus in swine herds, eastern China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the seasonal prevalence of genotype-IV hepatitis E virus (HEV) in swine herds in Eastern China and explore the phylogenetic relationship between swine HEV and human HEV in the situation that zoonotic features of HEV had been confirmed.</p><p><b>METHODS</b>From September 2007 to June 2008, a total of 1200 swine bile specimens were collected from three slaughter houses located in Zhejiang, Anhui and Jiangsu, the Eastern China, and detected for HEV RNA by using nested RT-PCR. The positive PCR products were sequenced. Then the swine HEV were phylogenetically determined with human HEV isolated in Eastern China.</p><p><b>RESULTS</b>The positive rate for HEV RNA in swine herds was 4.5% totally. Significant differences of HEV detection were not observed among seasonal pattern (Sep - Oct: 6%, Dec - Jan: 4.33%, Mar - Apr: 4.33%, May - Jun: 3.33%) but in geographic distribution (Jiangsu: 6%, Anhui: 5%, Zhejiang: 2.5%). Regardless of isolation from different areas,swine and human genotype-IV HEV shared a high similarity. Phylogenetically, there were 80% - 100% and 96% - 100% identities within swine genotype-lV HEV at the nucleotide and amino acid levels respectively. Between swine HEV and human HEV, there were also similarities of 76% -99% and 95% - 100%. It was noted that some human and swine isolates were clustered with bootstrap values of > 90%.</p><p><b>CONCLUSION</b>Genotype-IV HEV is widely prevalent in swine herds in Eastern China and original common ancestor of evolution and transmission was implied. The sustaining prevalence within swine herds should have a probable influence on the epidemic situation of hepatitis E in human beings.</p>