Risk taking high in those with resistant strains

Targeted interventions needed, researchers say

A recent study shows that there is no difference in high level of sexual risk-taking behavior between HIV-infected populations who have drug-resistant virus and those that don’t, which suggests that a public health problem may worsen unless it’s addressed through targeted intervention efforts.1

Clinicians and public health officials are seeing increases in the number of new patients who have antiretroviral-resistant HIV infections, but there has been little published to help them understand some of the behaviors that might lead to HIV-resistant virus, says Peter V. Chin-Hong, MD, assistant professor in the division of infectious diseases, department of medicine at the University of California, San Francisco.

Researchers have had multiple theories on why there hasn’t been a faster and larger rise in drug-resistant virus among newly infected populations since drug-resistant virus now is common, he notes.

"One group thinks that if individuals with drug-resistant virus were having as much sex as everyone thinks they’re having, then we should see more individuals who are recently infected with drug-resistant virus," Chin-Hong says. "The other camp is saying that the rate is increasing and we think that individuals with drug-resistant virus are having as much unsafe sex as individuals without drug-resistant virus, but nobody knows what’s happening."

Chin-Hong and co-investigators took a snapshot look at what’s happening in the epidemic in San Francisco with regard to drug-resistant virus, sexual risk behaviors, and new infections.

They studied a population that came to health clinics for treatment, and this included 287 men and women who were given a drug-resistance genotypic test, he says.

The people who had drug resistance were sorted into one group, and those who did not have resistance were placed in another group. "We asked them about sexual behaviors in a self-administered baseline questionnaire, and we gave them the questionnaire every four months, but this report is based on the baseline information," Chin-Hong adds.

"In general, we found that individuals with drug-resistant virus had the same behaviors as those without drug-resistant virus — there was no statistical difference," he says. "Specifically, the highest risk behaviors were among men who have sex with men (MSM) who had unprotected anal sex with non-HIV-positive or unknown partners."

Again, there was no statistical difference in behaviors among the MSM group with drug resistance and the MSM group without drug resistance, Chin-Hong notes. "Some patients would say, I only have unsafe sex with people I know are positive.’ However, all of the groups were having unsafe sex with the most vulnerable groups, which are those who are HIV-negative or of unknown status."

When investigators divided subjects by age and gender, they found that the riskiest sexual behaviors were reported by people who were younger than 35 by a large ratio, he adds.

For the group of people younger than 35, unsafe behavior was reported by 60%, whereas for those older than 35, unsafe behavior was reported by 11%, he points out. "These [younger] folks grew up in an age of antiretroviral therapy and when HIV became a disease like hypertension and heart disease, and perhaps, they feel this sense of indifference to the gravity of what HIV disease means. They know they have antiretroviral treatment and if they infected someone with HIV, there wouldn’t be the same circumstances that they would have had 10 years ago."

Other factors that were associated with greater risk behavior included daily alcohol consumption, Viagra use, and depression, Chin-Hong explains. Adherence, education level, and race did not appear to make a significant difference. "Folks who reported Viagra use within the last four months were five times more likely to have engaged in unsafe sex than those who didn’t report Viagra use."

Less significant was the use of the so-called party drugs: "Folks were three times more likely to engage in unsafe sex if they took poppers, ecstasy, GHB, or methamphetamines in the last four months," he notes. "I think there’s something there, but it wasn’t conclusive significantly in our findings."

The effect of depression was an unexpected and interesting finding, Chin-Hong says. "Folks who reported recent depression in the last four months were two times more likely to engage in unsafe behaviors than those who didn’t report any depression, and that’s something we can diagnose. That’s an area where we could be doing a lot better job of asking patients about depression and developing an intervention."

Investigators have followed subjects for a year, and further study and analysis are necessary before researchers clearly may understand risk behavior and its impact on drug resistance, he states. "When they start treatment, does the virus change? Does their behavior change? When do they become resistant? It could be the wild type virus is much more fit and virulent than drug-resistant virus," Chin-Hong says. "But over time, the drug-resistant virus may have an advantage if the person [who is infected and transmits the virus] is taking drugs — it’s too early to tell."

The key point is that sexual risk behaviors remain high, particularly in younger groups, and this alone is cause for concern and renewed focus on interventions, he says.

Reference

1. Chin-Hong PV, Deeks S, Liegler T, et al. High-risk sexual behavior in HIV-infected adults with genotypically proven antiretroviral resistance. Presented at the 11th Conference on Retroviruses and Opportunistic Infections. San Francisco; February 2004. Abstract 845.