Risk of Herpes Type 2 Elevated Among Adults Who Are HIV-Positive

First published online:

| DOI: https://doi.org/10.1363/4414212

HIV-infected adults in the United States are three times as likely as adults in the general population to be seropositive for herpes simplex virus type 2 (HSV-2), according to a study comparing two contemporary cohorts.1 Within the HIV-infected cohort, a heightened risk of HSV-2 seropositivity was evident among a variety of groups, not all of whom engage in high-risk sexual behaviors. Specifically, the odds of testing positive for HSV-2 were roughly 3–4 times as high among individuals who were aged 30 or older, female or black as among those in their 20s, men or white, respectively. Additionally, those who were unemployed, had anal infection with a high-risk type of human papillomavirus or were more than about two years out from HIV diagnosis had nearly twice as high odds of testing positive as their peers who lacked these characteristics.

Investigators analyzed data from HIV-infected adults between the ages of 20 and 69 from four U.S. cities (Denver, Minneapolis, Providence and St. Louis) who enrolled in the Study to Understand the Natural History of HIV and AIDS in the Era of Effective Therapy (SUN) during 2004–2006. All were receiving medical care, and none had opportunistic infections. Participants completed computer-assisted self-interviews on risk factors and gave blood for HSV-2 serologic testing. The investigators also analyzed data from a nationally representative sample of adults from the general U.S. population who participated in the National Health and Nutrition Examination Survey (NHANES) during 2003–2006 and gave blood for HSV-2 serologic testing.

A first analysis compared the seroprevalence of HSV-2 between cohorts, including only adults who were 20–49 years old. The 548 SUN participants in this age-group had a median age of 39 years. Some 77% were male, and 59% were white. Most were on combination antiretroviral therapy, and three-fourths had low viral loads (less than 400 copies per microliter). NHANES participants in this age-group, who represented approximately 115 million individuals in the general population, had a median age of 34 years. Some 49% were male, and 67% were white. Fewer than 1% were infected with HIV.

The seroprevalence rate of HSV-2, standardized for age, sex and race, was 60% in the HIV-infected cohort, compared with 19% in the general population; the difference corresponds to roughly a tripling of the seroprevalence rate among those with HIV infection (rate ratio, 3.1). The findings were similar for men and women individually (3.5 and 3.3, respectively). HSV-2 seroprevalence also was elevated for white, Hispanic and black HIV-infected men and women (1.6–5.4 and 1.6–4.0, respectively).

In a second, multivariate analysis, restricted to the HIV-infected cohort but including all 660 participants regardless of age, those who were 30 or older had more than twice as high odds of having HSV-2 infection as 20–29-year-olds (odds ratios, 2.5–3.9). Risk was also elevated for women and the unemployed (3.0 and 2.0, respectively), and was higher among black participants than among their white peers (2.5). Two other groups with a heightened likelihood of testing positive for HSV-2 were individuals who had an anal infection with a type of human papillomavirus carrying a high risk of cancer (1.7) and individuals who had received their diagnosis of HIV more than 2.3 years earlier, putting them in the top 75% for this measure (1.5). Some of these risk factors mirrored those in the general population.

Additional multivariate analyses focused on specific subgroups in the HIV-infected cohort. Here, women had sharply elevated odds of being HSV-2 seropositive if they were older than 32, the cutoff for the top 75% of age (odds ratio, 3.6), were black (3.0) or were unemployed (4.4). And men who had sex with men had an increased risk if they were 30 or older (3.6–8.0), were black (2.9) or had a history of injection-drug use (3.6).

The study reveals "striking differences" in the seroprevalence of HSV-2 between HIV-infected adults and the general population, according to the investigators. Even so, they caution that the findings may not apply to all HIV-infected adults, as those studied were in care and generally had well-controlled infection. "Clinicians should be aware that the risk for HSV-2 infection is broadly distributed among HIV-infected adults…and does not necessarily concentrate among persons who report high-risk sexual behaviors," they maintain. Accumulating data suggest that suppressing HSV with antiviral therapy may slow progression of HIV in people having both infections; it therefore may not only benefit those individuals, but also reduce HIV transmission to others, according to the investigators. Thus, "routine screening of HIV-infected patients for HSV-2 infection in HIV clinics requires serious consideration," they conclude.—S. London