High rate of missed HIV infections in individuals with indeterminate or negative HIV western blots based on current HIV testing algorithm in China

Using signal-to-cutoff ratios of HIV screening assay to predict HIV infection

BACKGROUND

The sensitivity of HIV screening assays often leads to a high rate of false-positive results, requiring retests and confirmatory tests. This study aimed to analyze the capability of signal-to-cutoff (S/CO) ratios of HIV screening assay to predict HIV infection.

METHODS

A retrospective study on the HIV screening-positive population was performed at Zhongshan Hospital, Xiamen University, the correlation between HIV screening assay S/CO ratios and HIV infection was assessed, and plotted Receiver Operating Characteristic (ROC) curves were generated to establish the optimal cutoff value for predicting HIV infection.

RESULTS

Out of 396,679 patients, 836 were confirmed to be HIV-infected, with an HIV prevalence of 0.21%. The median S/CO ratios in HIV infection were significantly higher than that in non-HIV infection (296.9 vs. 2.41, P < 0.001). The rate of confirmed HIV infection was increased with higher S/CO ratios in the screening assay. The ROC curve based on the HIV screening assay S/CO ratio achieved a sensitivity of 93.78% and a specificity of 93.12% with an optimal cutoff value of 14.09. The area under the ROC curve was 0.9612. Further analysis of the ROC curve indicated that the S/CO ratio thresholds yielding positive predictive values of 99%, 99.5%, and 100% for HIV infection were 26.25, 285.7, and 354.5, respectively.

CONCLUSION

Using HIV screening assay S/CO ratio to predict HIV infection can largely reduce necessitating retests and confirmatory tests. Incorporating the S/CO ratio into HIV testing algorithms can have significant implications for medical and public health practices.

Point-of-Care HIV Test for a Promising Simple and Rapid Clinical HIV Definite Diagnosis Process

BACKGROUND

This study compared and evaluated the performance of a commercially available HIV POC rapid test with assays commonly used in clinical laboratories, including enzymelinked immunosorbent assay (ELISA), western blot (WB), and reverse transcription-polymerase chain reaction (RT-PCR).

METHODS

500 patients' samples were detected by the POC rapid test and clinically common tests (WB, ELISA, and RT-PCR) to compare detection performance, test time, and test cost.

RESULTS

Taking the WB results as the gold standard, the results of RT-PCR were completely consistent with WB. The concordance of ELISA and POC with WB was 82.00% and 93.80%, respectively, with statistically significant differences (p<0.05).

CONCLUSION

This study provides evidence that rapid HIV POC assays are superior to ELISA and that WB and RT-PCR have equal detection performance in detecting HIV. As a result, a rapid and costeffective HIV definition process based on the POC assays can be proposed.

Assessing donor suitability for blood donation: Utility of Geenius HIV 1/2 confirmatory assay

BACKGROUND

Blood donor care and blood safety require a quick and accurate decision on the presence or absence of Human Immunodeficiency Virus (HIV) infection, based on the proper selection of blood donors, serological and molecular HIV testing as well as western blot test. The aim was investigating the possibility of inclusion of Geenius HIV 1/2 Confirmatory Assay in blood donor testing algorithm in order to shorten test time and decrease the number of indeterminate results.

METHODS

A total of 75 archived serum/plasma samples were tested. Their previous serological and molecular HIV results were: 3 negative samples, 7 positive samples, 65 serological indeterminate or positive but confirmatory testing and NAT negative samples.

RESULTS

Geenius assay confirmed the presence of antibodies in all blood donors with HIV positive serology and Nucleic Acid Testing (NAT). HIV-1 gp160 and gp41 antibodies were detected in these donors, while p31 and p24 antibodies were not detected in two and three donors, respectively. HIV-2 antibodies gp36 and gp140 were not found. Blood donor with HIV indeterminate or positive serology but negative confirmatory testing and NAT, were negative in Geenius assay. Conclusion The results obtained are consistent with western blot results. The assay proved simple and quick to perform. Studies have confirmed the possibility of introducing Bio-Rad Geenius into a routine blood donor testing protocol.

Increasing Condomless Anal Intercourse and HIV Prevalence Among Men Who Have Sex with Men Who Have Never Been Tested for HIV Before: A Serial Cross-Sectional Study in Shenyang, China from 2012 to 2016

Despite the high HIV incidence among men who have sex with men (MSM) in China, over half of MSM have never been tested for HIV before (MSMNT). Through a serial cross-sectional study from 2012 to 2016 in Shenyang, China, we studied 1036 MSMNT, and diagnosed 16.2% (168/1036) with HIV. The percentage of MSMNT who had condomless anal intercourse (CAI) in the past year increased from 42.1% (130/309) in 2012 to 63.4% (102/161) in 2016 (P < 0.001). 61.9% (104/168) of HIV-positive MSMNT had CAI and this percentage remained constant for the study period (P = 0.593). 53.3% (463/868) of HIV-negative MSMNT had CAI and this percentage significantly increased over the study period (P < 0.001). Encouraging HIV testing in this key subset through online HIV risk self-evaluation tools and HIV self-testing kits may help mitigate the overall MSM HIV incidence.

Anti-HIV-1 antibodies based confirmatory results in Wuhan, China, 2012-2018

The number, intensity and order of emergence of HIV-1 specific antibodies in serum or plasma were associated with the stage of HIV-1 infection. In this study, we retrospectively analyzed the HIV-1 confirmatory results tested by western blot (WB) or recombination immunoblot assay (RIBA) in Wuhan, 2012-2018, to access the profiles of HIV-1 specific antibodies. A total of 14432 HIV-suspected serum or plasma samples collected from local hospitals and other HIV screening laboratories were further screened by two 4th generation enzyme-linked immunosorbent assay (ELISA) kits in our laboratory, of which 11068 specimens (76.69%) had at least one positive ELISA result and thereby were finally confirmed with WB or RIBA. RIBA had identified 652 (81.09%) positive and 13 (1.62%) indeterminate cases from July 1, 2014 to January 7, 2015, while WB had identified 8358 (81.43%) positive and 643 (6.26%) indeterminate cases in the other times during 2012-2018. The indeterminate rate of WB was significant higher than that of RIBA (p<0.001). Although the number of HIV-1 infected subjects increased significantly from 2012 (n = 911) to 2018 (n = 1578), the positive rate of HIV-1 antibodies decreased markedly from 70.08% in 2012 to 58.79% in 2018 (p<0.001). The most commonly observed antibody profile was gp160+gp120+p66+(p55+)p51+gp41+p31+p24+p17+ (4131, 49.43%) for WB-MP and gp160+gp120+gp41+p31+p24+p17+ (382, 58.59%) for RIBA-WANTAI, and the absence of reactivity to three possible serologic markers for recent HIV-1 infection, p31, p66, and p51, increased significantly from 2012 to 2018, with the overall rate of 17.03%, 9.40%, and 15.15%, respectively. The suspected acute HIV-1 infection was also observed to be increased in recent years, with an overall rate of 1.00%. Our results indicated the detection rate had decreased for HIV-1 infection, but increased for suspected recent and acute HIV-1 infection during 2012-2018, reflecting the efforts of intervention among high risk population.

HIV and other STIs self-testing to reduce risk compensation among men who have sex with men who use oral pre-exposure prophylaxis in China: protocol for a randomised waitlist-controlled trial

INTRODUCTION

Pre-exposure prophylaxis (PrEP) reduces the risk of HIV infection among men who have sex with men by up to 99%. However, in real-world settings, PrEP users may exhibit risk compensation after uptake of PrEP, including more condomless anal intercourse (CAI) and increased sexually transmitted infection (STI) acquisition. HIV self-testing (HIVST) decreases CAI among men who have sex with men (MSM) by providing awareness of the HIV status of oneself and one's sexual partners. Here, we describe the rationale and design of a randomised waitlist-controlled trial to examine the impact of HIVST on risk compensation among PrEP users.

METHODS AND ANALYSIS

The study is a two-arm randomised waitlist-controlled trial with 1000 HIV-negative MSM in four major cities in China who will be taking oral PrEP (involving tenofovir disoproxil fumarate/emtricitabine) either daily (n=500) or in an event-driven regimen (n=500). The participants will be randomised (1:1) to either the immediate HIVST intervention arm (HIVST plus standard facility-based counselling and testing from 0 to 12 months) or the waitlist arm (standard facility-based counselling and testing from 0 to 6 months, then crossover to receive the HIVST intervention in months 7-12). Participants will provide blood samples to assess the incidence of syphilis and herpes simplex virus type 2 (HSV-2) during a follow-up. The primary outcomes will be the occurrence of CAI, number of sexual partners and incidence of syphilis and HSV-2 during a follow-up. The secondary outcomes will be the HIV and STI testing frequency and STI treatment adherence during a follow-up. The planned start and end dates for the study is 26 December 2018 and 31 December 2020.

ETHICS AND DISSEMINATION

The Medical Science Research Ethics Committee of The First Affiliated Hospital of China Medical University has approved the study (IRB(2018)273).

TRIAL REGISTRATION NUMBER

ChiCTR1800020374.

Estimation of the Seroconversion Duration of HIV-1 Antibodies in Individuals With Recent Infection in China

The identification of recent HIV-1 infection is clinically important for the effective treatment and prevention of transmission. However, the window period for seroconversion with respect to various HIV-1 antibodies is not well characterized. In addition, the routine HIV testing algorithms are not particularly appropriate for the identification of recent HIV-1 infection. In this study, we enrolled individuals who showed seroconversion from negative Western blot (WB) or indeterminate WB results and analyzed the window periods for appearance of HIV-1 antibodies. A total of 10,934 individuals with suspected HIV infection were tested by Wuhan CDC between 2012 and 2017; of these, 40 individuals with initial negative WB and 102 individuals with initial indeterminate WB who showed positive WB results within 100 days were included in the analysis. The mean time for seroconversion was 43.90 (95% confidence interval [CI]: 37.30-50.50) days and 42.15 (95% CI: 37.99-46.30) days, respectively. The time duration for p31 seroconversion among people with negative WB and indeterminate WB was 58.11 (95% CI, 44.30-71.92) days and 51.91 (95% CI, 44.55-59.28) days, respectively, both of which were significantly longer (p = 0.0169) than those in people without p31 seroconversion. A similar difference was observed with respect to p66 seroconversion, with a window time of 53.53 (95% CI, 43.54-63.52) days and 47.87 (95% CI, 43.16-52.57) days among people with negative WB and indeterminate WB, respectively. These data suggest that HIV-1 antibody p66, like p31, may serve as a potential serological marker for distinguishing Fiebig stage V and stage VI at day 70 post-infection.

Evaluation of the Bio-Rad Geenius HIV 1/2 Assay as Part of a Confirmatory HIV Testing Strategy for Quebec, Canada: Comparison with Western Blot and Inno-Lia Assays

The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1 Western blot (WB) confirmatory assay. A total of 370 retrospective samples collected from 356 patients were tested.

The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1 Western blot (WB) confirmatory assay. A total of 370 retrospective samples collected from 356 patients were tested. Sensitivity of the Geenius assay to detect HIV-1 and HIV-2 infections was 100% and 97%, respectively, and that of the WB assay was 86% and 39%, respectively. Geenius reduced the number of indeterminate results by 85% and exhibited a differentiation capacity for HIV-1 and HIV-2 of 100% and 89%, respectively. Three of 10 patients presenting with an early HIV infection (1 to 2 weeks before seroconversion by WB) were positive using Geenius. None of the HIV-negative samples were positive using Geenius or WB. However, 7% and 10% of them were indeterminate with Geenius and WB, respectively, leading to a specificity rate of 93% for Geenius and 90% for WB. Ninety cadaveric samples (54 negative, 23 HIV-1 positive, and 3 HIV-1 indeterminate) were tested with Geenius, leading to a sensitivity of 100%, a specificity of 96%, and an indeterminate rate of 4%. Our results indicate that the Bio-Rad Geenius HIV 1/2 rapid test exhibits better sensitivity to detect HIV-1 infections and better performance than WB to confirm and differentiate between HIV-1 and HIV-2 infections. The performance of this new confirmatory assay to detect early infections, to reduce the rate of indeterminate status, and to confirm HIV-1 infection in cadaveric blood samples makes Geenius a potent reliable alternative to the WB.