Analysis of HIV-1 genetic subtype and pretreatment drug resistance among men who have sex with men infected with HIV-1 from 19 cities of 6 provinces in China / 中华流行病学杂志

Objective: To investigate the distribution of HIV-1 genetic subtypes and pretreatment drug resistance (PDR) among men who have sex with men (MSM) from 19 cities of 6 provinces in China. Methods: From April to November 2019, 574 plasma samples of ART-naive HIV-1 infected MSM were collected from 19 cities in Hebei, Shandong, Jiangsu, Zhejiang, Fujian, and Guangdong provinces, total ribonucleic acid (RNA) was extracted and amplified the HIV-1 pol gene region by nested polymerase chain reaction (PCR) after reverse transcription. Then sequences were used to construct a phylogenetic tree to determine genetic subtypes and submitted to the Stanford drug resistance database for drug resistance analysis. Results: A total of 479 samples were successfully amplified by PCR. The HIV-1 genetic subtypes included CRF01_AE, CRF07_BC, B, CRF55_01B, CRF59_01B, CRF65_cpx, CRF103_01B, CRF67_01B, CRF68_01B and unrecognized subtype, which accounted for 43.4%, 36.3%, 6.3%, 5.9%, 0.8%, 0.8%, 0.4%, 0.4%, 0.2% and 5.5%, respectively. The distribution of genetic subtypes among provinces is statistically different (χ2=44.141, P<0.001). The overall PDR rate was 4.6% (22/479), the drug resistance rate of non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors were 3.5% (17/479), 0.8% (4/479) and 0.2% (1/479), respectively. The PDR rate of recent infections was significantly higher than that of long-term infections (χ2=4.634, P=0.031). Conclusions: The HIV-1 genetic subtypes among MSM infected with HIV-1 from 19 cities of 6 provinces in China are diverse, and the distribution of subtypes is different among provinces. The overall PDR rate is low, while the PDR rate of recent infections was significantly higher than that of long-term infections, suggesting the surveillance of PDR in recent infections should be strengthened.

Application of limiting antigen avidity enzyme immunoassay for estimating HIV-1 incidence in men who have sex with men / 中华流行病学杂志

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.

Molecular investigation of a possible case of HIV transmission after a blood transfusion / 中华预防医学杂志

<p><b>OBJECTIVE</b>A molecular technique based on quasispecies analysis for tracing postexposure HIV transmission was applied in an investigation of a possible case of HIV transmission after blood transfusion.</p><p><b>METHODS</b>Sixteen plasma specimens were collected from 3 HIV infections (T1-T3) involved in a possible HIV transmission chain and 13 HIV/AIDS (C1-C13) controls. The RNAs were extracted and then amplified by RT-PCR, the PCR products were cloned and sequenced.BioEdit 6.0.7 and MEGA 4.0 software were used to analyze gene sequences, calculate gene dispersion ratio and construct phylogenetic tree.</p><p><b>RESULTS</b>The sequences of 13 specimens were successfully obtained.The HIV strains from T1, T2 and T3 were CRF07_BC recombinants, those from 5 out of the 6 controls lived in the same city with T2 and T3 were CRF07_BC recombinants as well, while those from 4 controls living in the same city with T1 were CRF01_AE recombinants. Compared with the clone sequences from T1, the mean gene dispersion ratio of T2 was the least (2.0%), followed by C12 (2.8%) , T3 (2.9%) and others. The phylogenetic tree showed that all clones from T1, T2, T3 and C12 might cluster together,and implied that the direction of HIV transmission was from T3 to T2, and then to T1.</p><p><b>CONCLUSION</b>The results support the possible epidemiological clue that HIV was transmitted from T3 to T2, and then to T1, indicating that molecular epidemiological investigation could provide more direct evidence for tracing postexposure HIV transmission.</p>

Comparison of three HIV antibody confirmatory assay kits in confirming early HIV infection / 中华预防医学杂志

<p><b>OBJECTIVE</b>This study was to compare the performance of three HIV antibody confirmatory assay kits in confirming early HIV infection.</p><p><b>METHODS</b>Five HIV antibody-positive plasma specimens were ten-fold serially diluted and then detected by ELISA. The above diluted specimens were detected with the following three HIV antibody confirmatory assay kits to analyze their sensitivity, including Wantai-RIBA (Recombinant immunoblot assay, Beijing Wantai Biological Pharmacy, China), MP-WB (HIV Blot 2.2 WB, MP Biomedicals Asia Pacific Pte. Ltd., Singapore) and INNO-LIA (INNO-LIA(TM) HIV I/II Score, Innogenetics N.V., Belgium), respectively. These kits were further used to detect 48 ELISA-reactive specimens from 11 sets of HIV seroconversion specimens (a total of 48 samples) which were previously detected as HIV antibody-positive by ELISA.</p><p><b>RESULTS</b>When 5 samples were diluted to 100 fold, Wantai-RIBA still can detect them positive. Among the 48 HIV antibody-positive specimens detected with ELISA, the confirmation positive rate for Wantai-RIBA, MP-WB and INNO-LIA were 97.92% (47/48), 81.25% (39/48) and 91.67% (44/48), respectively. There was statistically significant difference between the confirmatory results of Wantai-RIBA and MP-WB (χ(2) = 6.13, P < 0.05), as well as between those of INNO-LIA and MP-WB (χ(2) = 5.48, P < 0.05); however, there was no statistically significant difference between those of Wantai-RIBA and INNO-LIA (χ(2) = 1.33, P > 0.05). For other six HIV seroconversion panels containing indeterminate specimens, the average seroconversion period of time for Wantai-RIBA, MP-WB and INNO-LIA were 0.7, 13.3 and 3.7 days, respectively.</p><p><b>CONCLUSION</b>Compared with MP-WB, Wantai-RIBA and INNO-LIA could reduce the window period to confirm early HIV infection.</p>

Determination of fumonisin biosynthesis gene and toxicity of Fusarium moniliforme strains isolated in China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the relationship between fumonisin biosynthesis gene and toxicity of Fusarium moniliforme isolated in China.</p><p><b>METHODS</b>The toxigenic gene of 29 Fusarium moniliforme isolated from different provinces and varied food samples were determined. Eighteen fum5-positive strains were selected for biosyhesizing fumonisin and determined by high performance liquid chromatography (HPLC).</p><p><b>RESULTS</b>Twenty-six isolates were identified as fum5 gene positive strains. And all of these strains produced FB(1), FB(2) and FB(3). The amount of FB(1), FB(2) and FB(3) was ranging from 0.41-140.20 mg/kg, 0.06-14.30 mg/kg to 0.30-58.00 mg/kg, except one strain produced a lower level of FB(1) only. It wight be the first report showing a high level fumonisin-producing strain isolated from the sesame sample and identified in the world. The amount of FB(1), FB(2) and FB(3) produced by the isolate was 128.84 mg/kg, 11.80 mg/kg and 14.88 mg/kg.</p><p><b>CONCLUSIONS</b>It should have a close relationship between fumonisins biosynthesis gene and toxicity of Fusarium moniliforme isolated in China. The study demonstrated that strain of Fusarium moniliforme might contaminate the sesame sample and produce a high level of fumonisins.</p>

Study on the fourth generation HIV antigen and antibody combination assays reducing the HIV diagnostic window period / 中华检验医学杂志

Objective To compare the ability of the fourth and the third generation HIV assay kits available in Chinese market to detect early HIV infection.Methods 8 BBI HIV seroconversion panels (PRB924,930,940,942,943,944,946 and 948) and 2 National AIDS Reference Lab's HIV seroconversion panels (2004XJ727 and 20505217) were respectively detected with one HIV antigen assay kit,2 fourth generation HIV assay kits and 4 third generation HIV assay kits.The ability of these kits to detect early HIV infection was analyzed and compared.Results For every panel,the fourth generation HIV assay kits could detect HIV-1 infection 4 to 8 days earlier than the third generation kits,and 2 to 4 days later than the antigen kit.The detection ability of different brands of kits was different.Conclusions The fourth generation HIV assay kits could reduce the window period to detect HIV infection.It's meaningful for diagnosing early HIV infection,blood safety and etc.