Concurrency and HIV transmission network characteristics among MSM with recent HIV infection

Abstract

Objective Sexual partner concurrency is common among men who have sex with men (MSM) and may increase the probability of HIV transmission during recent (acute or early) infection. We examined the relationship between concurrency and HIV transmission network characteristics (proxies for HIV transmission) among MSM with recent HIV infection. Design Observational study integrating behavioral, clinical, and molecular epidemiology. Methods We inferred a partial HIV transmission network using 986 HIV-1 pol sequences obtained from HIV-infected individuals in San Diego, California (1996-2015). We further analyzed data from 285 recently HIV-infected MSM in the network who provided information on up to three sexual partners in the past three months, including the timing of intercourse with each partner. Concurrency was defined as sexual partners overlapping in time. Logistic and negative binomial regression were used to investigate the link between concurrency and HIV transmission network characteristics (i.e., clustering and degree or number of connections to others in the network) among these MSM. Results Of recently HIV-infected MSM (N=285), 54% reported concurrent partnerships and 54% were connected by ≥1 putative transmission link to others (i.e., clustered) in the network (median degree=1.0; interquartile range: 0.0-3.0). Concurrency was positively associated with HIV transmission network clustering (adjusted odds ratio=1.83, 95% confidence interval [CI]: 1.08-3.10) and degree (adjusted incidence rate ratio=1.48, 95% CI: 1.02-2.15) Conclusions Our findings provide empirical evidence consistent with the hypothesis that concurrency facilitates HIV transmission during recent infection. Interventions to mitigate the impact of concurrency on HIV transmission may help curb the HIV epidemic among MSM.

Sexual Partner Concurrency Among Partners Reported by MSM with Recent HIV Infection

“…As previously described (8,16), through 2006, recent infection was documented among individuals reporting possible exposure to HIV or symptoms consistent with acute infection in the presence of one of the following: (1) negative HIV antibody (Ab) test (enzyme-linked immunoassay [EIA] or rapid test) followed by positive HIV Ab test in the past 12 months, (2) a negative HIV Ab test and positive HIV RNA, or (3) positive HIV Ab test and detuned EIA results consistent with early infection (Vironostika LS EIA, bioMerieux; Durham, NC). Starting in 2007, the Early Test protocol was implemented to screen for recent infection among all individuals seeking HIV testing: rapid HIV Ab testing followed by detuned EIA testing for those with positive rapid test results and HIV nucleic acid amplification testing (NAAT) for those with negative rapid test results (17).…”

“…As previously described (8), SD-PIRC participants completed computer-assisted self-interviews (CASIs) between January 2002 and November 2008 (Wave 1), May 2009 and May 2011 (Wave 2), or June 2011 and June 2015 (Wave 3). CASIs collected data on socio-demographics (age; race/ethnicity; education), sexual behaviors in the past three months (number of male sexual partners), and illicit drug use in the past three months (marijuana; methamphetamine; ecstasy; amyl nitrite; cocaine; gamma-hydroxybutyric acid; ketamine; heroin).…”

“…As previously described (8), we first converted participants’ responses to questions about the timing of sexual intercourse with partners to days to identify their period of sexual activity with each partner (i.e., dates of first and last sexual intercourse). Next, we identified concurrent partners by examining the overlap between periods of sexual activity for each pair of partners reported by a participant.…”

“…Sexual partner concurrency (i.e., “overlapping sexual partnerships”) (2) is hypothesized to facilitate HIV transmission in the context of recent (acute or early) infection by enhancing the probability that one’s partners are exposed during their period of increased infectiousness following HIV acquisition (3,4). High rates of concurrency have been documented among MSM in the United States (5–8), and it has been estimated that MSM are 2-3 times as likely as heterosexual men to report concurrent partners in the past year (9). As such, concurrency may contribute to the continued burden of HIV infection among MSM in the United States.…”

Characteristics of HIV-1 Molecular Transmission Networks and Drug Resistance Among Men Who Have Sex with Men in Tianjin, China (2014-2018)

“…Clustering performed based on partial pol was mostly sustained by the env sequences (Fig 2-B), except that two pol clusters were identi ed as 4 clusters because of two env clusters divided into two smaller clusters respectively. Thus, 36 robust clusters including 110 individuals (25.2%, 110/436) were identi ed according the clustering consistency analyzed and reference to relevant literature [14,15] . Of the 110 clustered individuals in the 36 clusters, 78.2% (86/110) were in 32 small clusters (including 2-5 nodes) and 21.8% (24/110) were in four large clusters (including >5 nodes) (Fig 1 and Fig 2).…”