Gay men change their sexual behaviour following diagnosis with HIV - at least in the short term

Diagnosis with HIV leads to changes in the sexual and drug-use behaviours of gay men, US investigators report in the online edition of the Journal of Acquired Immune Deficiency Syndromes.

There was a reduction in the number of reported sex partners, and in the first few months after diagnosis there was a reduction in unprotected sex with HIV-negative partners or men of unknown HIV status.

Rates of reported methamphetamine use fell, but still remained high. There was no evidence that individuals were using viral load to guide their decisions about unprotected sex.

“Our findings demonstrate how sexual behaviours, partnership status, substance abuse and partner choices of MSM [men who have sex with men] with recent HIV infection changed during the first year following diagnosis,” write the investigators.

Gay and other men who have sex with men continue to be a main focus of the HIV epidemic in industrialised countries such as the US. Recent research suggests that between 25 and 50% of all new infections originate in individuals who have been recently infected with the virus.

These individuals are an increasing focus of HIV prevention efforts, and to gain a better understanding of the risk behaviours of these patients, investigators in southern California designed a study involving 193 gay men who had recently been infected with HIV.

At the time of their diagnosis and at regular intervals over the following twelve months, they were interviewed about the type of sex they were having and their drug use.

The men had an average age of 35, and 71% were white. They were highly educated and 88% had attended college.

At baseline, the men reported a mean of nine sex partners in the previous three months. This fell to a mean of seven partners in the three months after their diagnosis, and there was a further slight fall at twelve months (mean, six partners).

The proportion of men who reported a main partner increased from 20% at baseline to 48% at the end of the study. This increase was significant (p < 0.001).

Almost half (46%) of men reported unprotected sex with a recent partner at the beginning of the study. This fell to 39% after nine months, but then increased sharply to 57% at the end of the study.

There was some evidence that men were serosorting, At baseline, 14% reported having a partner who was HIV-positive, and this increased to 33% at month three and 39% at the end of the study. The proportion of men reporting recent unprotected sex with an HIV-negative partner, or man of unknown status, fell from 42% at baseline to 23% at month nine. However, the proportion increased to 50% at month twelve.

Methamphetamine use was widespread. At baseline, 30% reported using the drug during their last sexual encounter. This fell to 11% at month three and remained steady for the rest of the study. However, over the twelve months of the study, the proportion of methamphetamine users reporting risky sex increased significantly (p = 0.05).

“The methamphetamine use reported in this sample is of great concern,” comment the investigators. In their statistical analysis unprotected anal sex was associated with the use of methamphetamine at baseline (adjusted odds ratio [AOR], 7.65; 95% CI, 1.87-31.30), as well as use of methamphetamine during the study (AOR, 14.4; 95% CI, 2.02-103.0).

There was no evidence that sexual behaviour was guided by viral load. Unprotected sex was reported by 44% of men with an undetectable viral load and 48% of those with detectable HIV.

“In this cohort, men with recent HIV infection reduced their total number of partners over the first year of infection; with the greatest decrease in the first six months,” comment the investigators.

Rates of unprotected sex with men who were negative or of unknown status initially fell, but then increased, leading the investigators to believe “there is the potential for HIV transmission occurring to many different men”.

Behaviour change was most likely to occur in the six months after diagnosis, and the researchers believe a priority should be “programs to support the maintenance of such changes…particularly after nine months.”