Strategy for early detection of HIV infection in population at high risk in Tianjin

Objective To discuss the appropriate early HIV detection strategy in population at high risk in Tianjin by using existing HIV-1 antibody screening and testing system to compare the effect of combination of collection nucleic acid detection, p31 bands analysis and BED detection. Methods The serum samples were collected from men who have sex with men (MSM) in Tianjin in 2013 for nucleic acid detection. The generation Ⅲ HIV antibodies were used to test the samples first, and reconfirming test was conducted for positive samples. For negative samples, generation Ⅳ HIV antibodies were used to test the samples then, and reconfirming test was conducted for the positive samples. For the negative samples, nucleic acid sequencing was conducted. Among the newly diagnosed HIV infection (CD4 count200) by WB during 2012-2013, some were identified as recent and previous infections by BED detection and p31 bands analysis was conducted for them. Results Generation Ⅲ reagents were used to screen 2320 MSM cases and 140 positive cases were detected. For 2180 negative cases detected by generation Ⅲ reagents, generation Ⅳ reagent was used, and another 19 positive cases were detected. WB confirmed that 6 cases were positive, 11 cases were negative and 2 cases were uncertain. Nucleic acid detection was conducted for the 13 negative and uncertain cases were, and 4 were positive. Among the 2161 negative cases screened by generation Ⅳ reagents, collected nucleic acid detection confirmed 1 positive case. Nucleic acid detection found 5 positive cases. From p31 bands of WB results, p31 negative cases accounted for 23.9% (28/117) in the new infection cases, No long-term infection was found(0/177), and 1 AIDS case was found with a ratio of 1.1% (1/95), the difference was significant. Conclusion It is necessary to take targeted detection measures for different populations at high-risk and strengthen the consecutive surveillance in HIV positive MSM to find out their infection time and new infection proportionin Tianjin.