Screening Yield of HIV Antigen/Antibody Combination and Pooled HIV RNA Testing for Acute HIV Infection in a High-Prevalence Population

IMPORTANCE

Although acute HIV infection contributes disproportionately to onward HIV transmission, HIV testing has not routinely included screening for acute HIV infection.

OBJECTIVE

To evaluate the performance of an HIV antigen/antibody (Ag/Ab) combination assay to detect acute HIV infection compared with pooled HIV RNA testing.

DESIGN, SETTING, AND PARTICIPANTS

Multisite, prospective, within-individual comparison study conducted between September 2011 and October 2013 in 7 sexually transmitted infection clinics and 5 community-based programs in New York, California, and North Carolina. Participants were 12 years or older and seeking HIV testing, without known HIV infection.

EXPOSURES

All participants with a negative rapid HIV test result were screened for acute HIV infection with an HIV Ag/Ab combination assay (index test) and pooled human immunodeficiency virus 1 (HIV-1) RNA testing. HIV RNA testing was the reference standard, with positive reference standard result defined as detectable HIV-1 RNA on an individual RNA test.

MAIN OUTCOMES AND MEASURES

Number and proportion with acute HIV infections detected.

RESULTS

Among 86,836 participants with complete test results (median age, 29 years; 75.0% men; 51.8% men who have sex with men), established HIV infection was diagnosed in 1158 participants (1.33%) and acute HIV infection was diagnosed in 168 participants (0.19%). Acute HIV infection was detected in 134 participants with HIV Ag/Ab combination testing (0.15% [95% CI, 0.13%-0.18%]; sensitivity, 79.8% [95% CI, 72.9%-85.6%]; specificity, 99.9% [95% CI, 99.9%-99.9%]; positive predictive value, 59.0% [95% CI, 52.3%-65.5%]) and in 164 participants with pooled HIV RNA testing (0.19% [95% CI, 0.16%-0.22%]; sensitivity, 97.6% [95% CI, 94.0%-99.4%]; specificity, 100% [95% CI, 100%-100%]; positive predictive value, 96.5% [95% CI, 92.5%-98.7%]; sensitivity comparison, P < .001). Overall HIV Ag/Ab combination testing detected 82% of acute HIV infections detectable by pooled HIV RNA testing. Compared with rapid HIV testing alone, HIV Ag/Ab combination testing increased the relative HIV diagnostic yield (both established and acute HIV infections) by 10.4% (95% CI, 8.8%-12.2%) and pooled HIV RNA testing increased the relative HIV diagnostic yield by 12.4% (95% CI, 10.7%-14.3%).

CONCLUSIONS AND RELEVANCE

In a high-prevalence population, HIV screening using an HIV Ag/Ab combination assay following a negative rapid test detected 82% of acute HIV infections detectable by pooled HIV RNA testing, with a positive predictive value of 59%. Further research is needed to evaluate this strategy in lower-prevalence populations and in persons using preexposure prophylaxis for HIV prevention.

Unreported Male Sex Partners Among Men with Newly Diagnosed HIV Infection - North Carolina, 2011-2013

Human immunodeficiency virus (HIV) prevention interventions, such as preexposure prophylaxis (PrEP), are often targeted to men who have sex with men (MSM) who self-report high-risk behaviors. Data from a prospective study evaluating methods to detect acute HIV infection among a primarily young (aged <25 years) and black or African American (African American) population from North Carolina were analyzed. In the study, participants were asked about risk behaviors during pretest counseling (at the time of testing) and then during a partner services interview (at HIV diagnosis). Participants whose disclosure of sexual risk behaviors during pretest counseling was different from their disclosure of sexual risk behaviors during their partner services interview were identified, and factors associated with these discordant responses were examined. Among 113 HIV-infected men, 26 (23.0%) did not disclose male sex partners at pretest counseling, but subsequently did disclose this information during their partner services interview. When compared with men who disclosed having male partners at pretest counseling, these 26 MSM who did not disclose male partners during pretest counseling were found to have a similar number of male partners during contact tracing, but were more likely to have a female partner (30.8% versus 6.9%). In addition, the proportions of MSM found to have at least one HIV-infected partner were similar for both groups (MSM who disclosed having male partners during pretest counseling and those who did not). To better customize HIV prevention interventions for MSM, HIV prevention programs might consider using novel strategies to accurately assess risk in this population.

HIV infection among partners of HIV-infected black men who have sex with Men - North Carolina, 2011-2013

The incidence of human immunodeficiency virus (HIV) infection has significantly increased among black men who have sex with men (MSM) in the United States, and young black MSM have been disproportionately affected. HIVinfected black MSM are also less likely to engage in HIV care and achieve viral suppression than MSM of other races/ethnicities. Engaging in care and achieving viral suppression is a multistep process that starts with diagnosis. Diagnosing persons unaware of their HIV status traditionally has been a critical component of HIV partner services, but partner services also provide an important opportunity to reengage HIVinfected partners in medical care. One approach for partner services involves contacting partners of persons with newly diagnosed HIV infection and using sexual and social network and molecular phylogenetic data to improve the continuum of HIV care among black MSM. To evaluate the effectiveness of that approach, results from a prospective partner services study conducted in North Carolina were examined, and one of the partner networks identified through this study was evaluated in depth. Overall, partner services were provided to 30 black, HIV-infected MSM who named 95 sex partners and social contacts, of whom 39 (41%) previously had been diagnosed with HIV infection. The partner network evaluation demonstrated that HIV-infected and HIV-negative partners were frequently in the same network, and that the majority of HIV-infected partners were already aware of their diagnosis but had not achieved viral suppression. Using partner services to ensure that HIV-infected partners are linked to care and treatment might reduce HIV transmission and might improve outcomes along the continuum of care.