Performance of rapid tests for HIV-1 antibody detection in paired serum and urine specimens of men who have sex with men / 中华微生物学和免疫学杂志

Objective:To compare the performance of rapid tests for HIV-1 antibody detection in serum and urine specimens of men who have sex with men (MSM) for investigating suitable technology in the prevention and control of AIDS in Beijing.Methods:A total of 874 cases of MSM were recruited in the AIDS clinic of Beijing Center for Disease Prevention and Control. HIV-1/2 antibody rapid test kit (Kit A, Alere Determine), urine HIV-1 antibody rapid test kit (Kit B, Wantai Biological Pharmacy) and HIV-1/2 antibody Western blot kit (Kit C, IMT) were used for antibody detection. The sensitivity, specificity and consistency of the three rapid test kits for HIV-1 antibody detection in serum and urine specimens were analyzed.Results:Among the 874 cases of MSM, 447 were positive for HIV-1 antibody (51.14%) and 427 were negative. One false negative result occurred by using Kit A and 23 by using Kit B. Taking Kit C as reference, the sensitivity of Kit A and Kit B was 99.78% and 94.85%, respectively; the specificity of both was 100%; the overall consistency was 99.89% ( Kappa=0.998) and 97.37% ( Kappa=0.947), respectively. Conclusions:Although the sensitivity of urine rapid test kit was not as sensitive as serum rapid test kit, it was more suitable for self-test due to its convenience in sampling, high safety and high accessibility. It was suggested that urine rapid test kit should be popularized in MSM population for HIV-1 antibody screening.

Analysis on factors associated with taking subsequent confirmation test among men who have sex with men after being tested positive in oral fluid HIV antibody test in Beijing / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the proportion and associated factors of taking subsequent confirmation test among men who have sex with men (MSM) after being tested positive in oral fluid HIV antibody test.</p><p><b>METHODS</b>By using successive sampling, 1 003 MSM, who were tested positive in oral fluid HIV antibody test in China-Bill & Melinda Gates Foundation AIDS prevention Program (Extension program) in Beijing during May 1 to December 31, 2013, were recruited. The inclusion criteria included: the objects were men who reported having sex with men; the objects aged more than 18 years old; the objects were tested positive in oral fluid HIV antibody test; the objects had not been reported as HIV positives in China Information System for Disease Control and Prevention previously. According to the program strategy, MSM grassroots organizations transferred the respondents to seek subsequent confirmation tests in specific Center for Disease Control and Prevention (CDCs) or hospitals. The subsequent confirmation tests included: fingertip blood HIV antibody rapid test, venous blood Enzyme Linked Immunosorbent Assay (ELISA) HIV antibody test and venous blood Western Blot (WB) HIV antibody test. Chi-square test was adopted to compare the proportion of taking subsequent confirmation tests in different groups. Nonconditional multivaritae binarylogistic regression analysis was taken to identify the associated factors with whether taking subsequent confirmation tests and to calculate the OR (95% CI) values.</p><p><b>RESULTS</b>The 1 003 respondents were (30.9 ± 9.1) years old. Among all objects, 87.8% (881/1 003) of them took fingertip blood HIV antibody rapid tests and the positive rate was 85.4% (752/881). 98.0% (737/752) of those who were identified as positive in fingertip blood HIV rapid tests took ELISA and WB tests, and the positive rate was 94.4% (696/737). Comparing with those who were expected to seek subsequent confirmation tests in CDCs, the OR (95% CI) value of those who were expected to seek tests in hospitals was 5.10 (1.69-15.36). The OR (95% CI) values of those who used condom sometimes and those who never used condom in anal sex were 5.81 (2.14-15.77) and 3.45 (2.00-5.97) respectively, in comparison with those who reported not having anal sex or using condom consistently in anal sex during the past 6 months. Comparing with the respondents recruited from the internet, the OR (95% CI) values of those recruited in bathrooms, parks/toilets and bars were 0.17 (0.05-0.53), 0.10 (0.04-0.29) and 0.22 (0.06-0.79) respectively. The likelihood of taking subsequent confirmation test decreased with the increase of number of male sexual partners in the past 3 months, and the OR (95% CI) value was 0.92 (0.86-0.99).</p><p><b>CONCLUSION</b>The potential HIV positive MSM in the bathroom, park/toilet and bars are less likely to take subsequent confirmation test. Those who do not use condom consistently during anal sex are more likely to seek subsequent confirmation test. Medical organization conducting subsequent confirmation tests is more likely to increase the confirmation test rate of potential HIV positive MSM. The number of male sexual partners has negative correlation with whether to accept the subsequent confirmation test.</p>

Subtype and sequence analysis of gag genes in HIV-1 circulating in sexual infectors in Beijing / 中华微生物学和免疫学杂志

Objective To investigate the subtype distribution and sequence characteristics of HIV-1 strains prevalent among sexual infectors in Beijing. Methods We collected the blood samples from 100HIV sexual infectors in Beijing during 2008 and separated plasma specimens. RNA was extracted from the plasma and the gag gene was amplified by RT-PCR and nest-PCR. The PCR products were sequenced directly and phylogenetic analyses of gag gene was performed using the MEGA4 software. Results Among 100 HIV-1 plasma samples,84 gag gene fragments were amplified and analyzed. Eight HIV subtypes including B(22 strains), B'(8 strains),C( 1 strain) ,CRF01_AE (38 strains) ,CRF02_AG (2 strains) ,CRF07_BC(9 strains) ,CRF08_BC(3 strains) and C/CRF01_AE recombinant like strain( 1 strain) were identified circulating in Beijing. Conclusion CRF01 _AE and subtype B were predominant in Beijing account for 45.2% and 26.2% and the surveillance of HIV gene variation should be paid more attention.

Characterization of intertype specific epitopes on adenoviruses hexon / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To characterize the intertype epitopes on human adenovirus (HAdV) hexon.</p><p><b>METHODS</b>Based on computerized analysis on adenoviruses sequence of genomic alignment, antigenicity prediction and 3-D structure characteristics of hexon subunit, several peptides of hexon of adenoviruses were chosen to be synthesized or recombinant proteins of the hexon were expressed in E. coli by use of PGEX-5X. To identify the existence of intertype epitopes, the antisera raised with synthetic peptides or purified recombinant proteins were analyzed with Western blot and immunofluorescent assay.</p><p><b>RESULTS</b>The results of Western blot indicated that both peptide and recombinant antibodies showed specific reactivities with hexons of HADv-3, 4, 7 individually. Meanwhile, typical stain of immunofluorescence was found on HeLa cells infected with these HAdV by incubation with peptide as well as recombinant antibodies. Also, antibodies raised against peptide recognized the recombinant hexon protein in which a corresponding region of peptides was covered.</p><p><b>CONCLUSIONS</b>Most of the predicted intertype epitopes of HAdV hexon wer e exclusively found in synthetic peptides and recombinant proteins. These intertype epitopes showed to be continuous and sequential which could be employed for development of antibodies of diagnostic use.</p>