Individuals with acute HIV infection employ a number of strategies in the weeks after their diagnosis to reduce the risk of passing on HIV to their sexual partners, according to a study presented to the US National HIV Prevention Conference on December 5th. Investigators from the University of California, San Francisco found individuals with acute infection reduced their number of partners, abstained from sex, increased their use of condoms and deliberately selected new sexual partners who were perceived to be HIV-positive.
HIV-positive individuals are most infectious in the months soon after they are infected with HIV. This period is often called acute or primary HIV infection and research suggests that up to 50% of HIV transmissions are attributable to individuals with acute infection (although other investigators contest this finding).
Reducing behaviour that involves a risk of HIV transmission during primary infection could therefore help reduce the spread of the virus.
Investigators wished to know if individuals diagnosed with acute HIV infection were selecting new sexual partners of the same HIV status. The selection of partners of the same HIV status is often called serosorting.
The study involved patients aged 18 years or older with laboratory evidence of acute HIV infection. These individuals completed two questionnaires, the first soon after their HIV diagnosis and the second eight weeks later. These questionnaires were designed to obtain demographic details, health history, sexual risk behaviour, use of drugs and alcohol and mental health state.
In particular, individuals were asked to provide information on the number of instances of anal or vaginal sex (with or without condoms) in the eight weeks before diagnosis with primary HIV infection and in the weeks that followed diagnosis. They were asked to say if their partners were perceived to be HIV-positive, HIV-negative or of unknown HIV infection status.
A total of 27 individuals were included in the investigators' analysis, all but one was gay, 48% were white, 41% Latino and 7% African American and the mean age was 33 years.
The mean number of sexual partners declined significantly after diagnosis with primary HIV infection from a mean of approximately nine in the eight weeks before diagnosis to a mean of three in the first five weeks after diagnosis with a mean of a further three partners in the next five weeks (reduction in the number of sexual partners, p
What’s more, the investigators noted that the number of partners who were HIV-positive increased significantly after diagnosis with acute HIV infection (p
Condom use increased after diagnosis. In the eight weeks before diagnosis with acute HIV infection, individuals reported a mean of twelve acts of unprotected sex and three acts of protected sex. But in the ten weeks after diagnosis, the patients reported a mean of 18 acts of unprotected sex and eight instances of protected sex. This increase in condom use was statistically significant (p
Sexual activity that involved a risk of HIV transmission declined after diagnosis. In the week weeks before primary HIV infection was detected, individuals reported a mean of five risky sex acts with partners of unknown HIV status, four such acts with partners thought to be HIV-negative, and two instances of risky sex with partners perceived to be HIV-positive. But in the ten weeks following diagnosis, individuals reported a mean of 18 risky sex acts with partners thought to be HIV-positive, and a mean of zero acts with partners perceived to be HIV-negative or of unknown HIV status. This change in behaviour post diagnosis was statistically significant (p
Interviews were conducted to establish the patients’ motivations for behavioural change.
One individual explained his reasons for abstaining from sex thus: “Well, I haven’t had any sexual feelings…I don’t want to have – or risk any – or put anybody at risk, and I think that’s what really bothers me as far as having sex, you know, And like, what if? What if?”
A decision to refrain from higher risk sexual activity was explained by one individual in the following terms: “I feel like I’m a little bit more conservative and cautious now. And careful. Careful because I don’t want to be STD-infected or infect somebody else.”
One patient said he had two reasons for avoiding HIV-negative sexual partners: “One, because they don’t know what I’ve been through, and they’ll never understand...Also I don’t think that I could trust someone, or be 100% with someone, that I could be a threat to.”
The investigators conclude that “diagnosis, itself, may constitute an important component of risk-reduction interventions for acute HIV infection.” But they acknowledge that further work is need to determine how long such risk-reduction behaviour will last after diagnosis, and to understand how people determine the HIV status of their sexual partners in order to serosort.
Steward WT et al. A move toward serosorting following acute HIV diagnosis: fndings from the NIHM multi-site acute HIV infection study. US National Prevention Conference, December 5th, 2007.