Establishment and application of multiplex PCR for non-O157 H7 STEC virulence genes detection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Traditional detection approaches for non-O157 STEC are both time and labour consuming in diseases surveillance. Virulence genes detection based on multiplex PCR could not only improve the detection efficiency but also increase the accuracy.</p><p><b>METHODS</b>Six virulence genes of non-O157:H7 (stx1, stx2, eae, hly, etpD, katP6) were detected by two groups of trebling PCRs. The multiplex PCRs were optimized by melting curve analysis in SYBR Green I real-time PCR. Testing result of multiplex PCR was consistent with serological testing.</p><p><b>RESULTS</b>The sensitivity limits of the multiplex PCR for stx1, stx2, eaeP, etpD, katP, and hly were 10 ng/ml, 120 ng/ml, 110 ng/ml,165 ng/ml, 85 ng/ml, and 15 ng/ml, respectively, which is similar with that of single PCR. When the multiplex PCR was applied in 120 adults and 90 children diarrhea samples detection, 13 cases were detected for non-O157 positive.</p><p><b>CONCLUSION</b>The method we established can be used for non-O157 STEC virulence genes detection and screening with high efficiency and accuracy.</p>

HIV prevalence and its associated factors among men who have sex with men in Chongqing / 中华预防医学杂志

<p><b>OBJECTIVE</b>To examine HIV prevalence and its associated factors among men who have sex with men (MSM) and provide the evidence for the intervention program among MSM.</p><p><b>METHODS</b>A face-to-face questionnaire interview was conducted among MSM recruited by snowball sampling method in Yuzhong, Jiulongpo and Shapingba district of Chongqing from July to September, 2007. Totally, 1044 MSM were recruited. Associated factors with HIV prevalence were analyzed using forward stepwise logistic regression that HIV status was the dependent variable and demographics, AIDS awareness, sexual behaviors and the status of the intervention were independent variables.</p><p><b>RESULTS</b>A total of 1044 MSM were surveyed. The rate of AIDS awareness was 89.5% among MSM. The rate of unprotected anal sex during the past 6 months was 63.8%. The prevalence of HIV and syphilis was 8.5% (89/1044) and 12.5% (131/1044) respectively. The multivariate analysis identified that the older MSM (OR = 1.69, 95% CI: 1.13 - 2.52), junior school education (OR = 1.89, 95% CI: 1.17 - 3.05), younger than 18 years old of the first sex (OR = 3.11, 95% CI: 1.20 - 8.02), more than 10 sexual partners (OR = 2.24, 95% CI: 1.24 - 4.02), the history of having sex with women (OR = 2.40, 95% CI: 1.64 - 3.51) and syphilis infection (OR = 4.52, 95% CI: 2.77 - 7.38) were independent risk factors associated with HIV infection.</p><p><b>CONCLUSION</b>The rate of unprotected anal sex was high, so were the prevalence of HIV and syphilis among MSM. It should be urgent to conduct the intervention to stop AIDS rapid transmission among MSM.</p>