No link found between undetectable HIV viral load and unsafe sex in Swiss cohort

This article is more than 21 years old.

Individuals with an undetectable HIV viral load are not more likely to have unprotected sex, according to data from the Swiss Cohort Study published in the August 1 st edition of the Journal of Acquired Immune Deficiency Syndromes. However, investigators did find people who have a regular partner who is also HIV-positive, and injecting drug users were significantly more likely to have unprotected sex.

The Swiss study was conducted between April 2000 and March 2001, and involved over 4,700 patients, 95% of all individuals enrolled in the cohort. The study was prompted by suggestions that optimism about HAART has led to an increase in risky sexual behaviour and had it two aims: to evaluate the sexual behaviour of the members of the cohort; and in particular, to see if there was any association between unprotected penetrative sex and an undetectable viral load (below 50 copies/mL).

Using a self-completed questionnaire, individuals were asked describe their sexual behaviour over the previous six months. This included specifying if they had a regular or casual partners (or both), the HIV-status of their partners, and if they used condoms always, sometimes, or never. Clinical and demographic data was collected from patients’ notes, including age, gender, ethnicity, HIV disease stage, use of HAART, and HIV viral load.

Glossary

multivariate analysis

An extension of multivariable analysis that is used to model two or more outcomes at the same time.

intravenous

Injected into a vein.

ribonucleic acid (RNA)

The chemical structure that carries genetic instructions for protein synthesis. Although DNA is the primary genetic material of cells, RNA is the genetic material for some viruses like HIV.

 

virological suppression

Halting of the function or replication of a virus. In HIV, optimal viral suppression is measured as the reduction of viral load (HIV RNA) to undetectable levels and is the goal of antiretroviral therapy.

On the basis of their responses, the investigators divided the cohort members into three mutually exclusive groups. Patients who had no partner, or reported no sex with their partner, or said that they always used condoms were classified as “denied unsafe sex”; those who said that they had had sex without a condom were classified as “reported unsafe sex”; and, individuals who neither reported nor denied unprotected sex as “possible unsafe sex.”

The overwhelming majority of patients, 81%, denied having unsafe sex, with 12% of patients reporting sex without condoms, and 7% neither reporting nor denying unprotected sex.

In multivariate analysis, reported unsafe sex was not associated with a viral load below 50 copies/mL (p>0.05), having an AIDS diagnosis or level of education.

However, people who had a partner who was also HIV-positive (OR 15.02, 95% CI, 12.1 – 19.1), had casual partners (OR 4.04, 95% CI, 3.07 – 5.31), injected drugs (OR 1.73, 95% CI, 1.33 – 2.26), or were from a non-white ethnic group (OR 1.50, 95% CI, 1.07 – 2.08), were significantly more likely to report sex without condoms.

Gay men were no more likely than other transmission groups to report unsafe sex, but were more likely not to deny having unprotected sex (OR 1.66, 95% CI, 1.32 – 2.10).

”In this study of a large, well-described HIV-infected population, there was no evidence of an association between unsafe sexual behavior and optimal viral suppression”, say the investigators, noting that “this is in contrast to other studies reporting increased rates of unprotected sex amongst individuals taking potent antiretroviral therapy and among those with suppressed HIV RNA.”

The investigators add, that from their data it appears that “individuals who take care of themselves by adhering to potent antiretroviral therapy are also more likely to take care of others and protect them from infection.”

However, subgroups including people with partners who were also HIV-positive, intravenous drug users, and people from non-white ethnic groups were more likely to report unprotected sex and the investigators conclude that they should be targeted with sexual health campaigns.

Further information on this website

Gay men realistic, not optimistic about HAART, says study - new story

Dark-side of HAART optimism – more unsafe sex and poor adherence - news story

Sexual health factsheets

References

Wolf K et al. Prevalence of unsafe sexual behavior among HIV-infected individuals: the Swiss cohort study. JAIDS 33: 494 – 499, 2003.