RESUMO
Objective To understand infection status of human immunodeficiency virus (HIV) and analyze the influencing factors among men who have sex with men (MSM) in Guangzhou. Methods Men who have sex with men (MSM) were recruited from 2014 to 2017. Face-to-face questionnaire survey was conducted to collect information of characterisitc and behaviors. Blood samples were used to detect HIV antibodie. Data were analyzed using SPSS 19.0. Results Among 2 419 MSM, 200(8.27%) participants were confirmed positive for HIV. Multivariate Logistic regression analysis showed that with Guangzhou and monthly economic income >0.5 million as reference, non-Guangzhou (OR=1.712, 95% CI: 1.176-2.492，P=0.005) and monthly economic income ≤0.5 million (OR=1.998, 95% CI: 1.409-2.833，P<0.001) were associated with HIV infection among MSM. Diagnosed syphilis (OR=2.461, 95% CI: 1.375-4.405,P=0.002) , undetected syphilis (OR=2.333, 95% CI: 1.635-3.331,P<0.001), anal sex role passive (OR=2.015, 95% CI: 1.244-3.267,P=0.004), both active and passive (OR=2.115, 95% CI: 1.374-3.251,P=0.001), non-using condoms every time during anal sex (OR=1.955, 95% CI: 1.374-2.781,P<0.001), non-fixed anal sex objects (OR=2.150, 95% CI: 1.463-3.160,P<0.001) were major risk factors for HIV infection among MSM. Conclusions The prevalance of HIV infection and high-risk sexual behavior were high among MSM in Guangzhou. It is urgent to expand the scope of HIV testing and advocate safe sexual behaviors among MSM.
RESUMO
The gene encoding the nucleocapsid (N) protein of vesicular stomatitis virus (VSV-NJ) was subcloned from pMD-VN5, and inserted into pBAD/Thio TOPO vector. The recombinant plasmid was identified by restriction analysis and PCR. It was sequenced to confirm the correct sequences and the correct junctional orientations of the inserted N gene. The results of SDS-PAGE and Western immunoblotting revealed that the N protein was expressed in Escherichia coli LGM194 in a high level and the recombinant fusion protein, which contained a N-terminal HP-Thioredoxin and a C-terminal polyhistidine tag. It had a molecular mass of approximately 63.5 kD and immunologically reactive activity. The recombinant protein was characterized and tested in an enzyme-linked immunosorbent assay (ELISA) format for potential application in the serodiagnosis of vesicular stomatitis using 186 serum samples from experimentally infected goats and guinea-pigs with VSV-NJ and VSV-IN, and from field origin and reference serum samples. The sensitivity and specificity of the ELISA were compared with those of the standard microtiter serum neutralization (MTSN) tests. The ELISA and MTSN test results were highly correlated for detection of VSV antibodies. The ELISA was as sensitive as the SN assay in detecting positive serum to VSV. The correlation between SN titers and ELISA titers was statistically significant. These data suggest that the recombinant fusion N protein of VSV could be used as a recombinant test antigen for the serodiagnosis of vesicular stomatitis. The ELISA based on the reconmbinant nucleocapsid protein may offer the best combination of rapidity, sensitivity, simplicity, economy, and laboratory biosafety of any of the methods yet developed for VSV serodiagnosis. This study lay on foundation for the development of the diagnosis methods in serology for VSV.
