Many People With Drug-Resistant HIV Having Unprotected Sex

A substantial number of HIV-positive individuals with proven resistance to antiretroviral drugs had unprotected sex with a partner to whom they could have transmitted drug-resistant HIV, according to a study from United States, published in the December 1st edition of the Journal of Acquired Immune Deficiency Syndromes.
“Our study demonstrates that among HIV-infected men and women harboring genotypically proven antiretroviral viremia, there is a substantial prevalence of high-risk sexual behaviour”, write the investigators who calculated that the 25 individuals with resistance and reporting risky sex could have infected as many as 72 people with drug-resistant HIV.
Evidence from the United States and United Kingdom suggests that the proportion of people being newly infected with drug resistant HIV is increasing. Although HIV prevention has increasingly focused on the behaviours of individuals who already know they have HIV, little is known about the risk behaviours of individuals who have drug-resistant HIV.
Investigators from the Study of the Consequences of the Protease Inhibitor Era (SCOPE) in San Francisco asked 287 individuals who were taking anti-HIV therapy to complete a questionnaire about their sexual behaviour in the previous four months. Patients were also asked to provide information on their mental health, adherence to antiretroviral therapy, recreational drug use (including use of the anti-impotence drug sildenafil (Viagra) and alcohol use.
Patients were divided into two groups: those with a viral load above 100 copies/ml and genotypically proven resistance to antiretroviral drugs and those with a viral load below 100 copies/ml.
Of the 287 individuals included in the investigators’ analysis, a total of 219 individuals identified as gay or bisexual, the median age was 45 years, 88% were men and 168 (58%) had a viral load above 100 copies/ml and genotypically proven resistance.
Unprotected anal sex was reported by 36 (27%) of the 133 gay or bisexual men with confirmed drug resistance, and 23 (17%) said that they had had unprotected sex with a partner who was HIV-negative or whose HIV status they did not know. Among the heterosexual men and women with resistance, four (11%) said that they had had unprotected sex and two (6%) said that this was with an individual who was either HIV-negative or of unknown HIV status.
The investigators then calculated how many new drug-resistant HIV infections this level of risk activity could have resulted in. They accepted a previous estimate that a plasma viral load of 1500 copies/ml is the threshold for transmission of HIV.
Among patients with proven drug-resistance, the median plasma viral load was 10,500 copies/ml, and the investigators remark “92% had a level greater than 1500 copies/ml.” These 25 individuals had a median of one partner who was HIV-negative or of unknown HIV status with which they had unprotected sex in the previous four months. However, 25% reported three or more partners. The investigators therefore calculated “summing the number of sexual partners per person reporting unsafe sex, as many as 72 previously HIV-uninfected or status unknown partners were exposed to and could have acquired drug-resistant HIV infection”.
Data were obtained on he spectrum of resistance mutations in individuals engaging in high-risk sex. Resistance to a single class of antiretrovirals was seen in 8% of patients, 44% had resistance to drugs from two classes of antiretroviral drugs, and 48% had resistance to drugs from all three main classes of anti-HIV drugs.
Attention was then turned to the risk factors associated with unprotected sex with an HIV-negative partner or partner of unknown status. Younger age (below 35 years, p < 0.001) was a strong predictor, and there was also evidence that depression (p < 0.018) and use of sildenafil (p < 0.039) were significantly associated with high-risk sex that involved potential exposure to drug-resistant HIV.
Factors associated with unprotected sex with other HIV-positive individuals were sildenafil use (p = 0.006), use of methamphetamine (p = 0.048) and frequent alcohol use (p = 0.027).
“We estimated that approximately one in four men or women with drug resistance in our clinic-based population engaged in unprotected intercourse in the past four months, including 15% with partners who were known to be HIV-uninfected or whose HIV status was unknown”, write the investigators.
They also comment, “we found no evidence that persons with drug resistance have been effectively targeted to reduce their practice of unprotected sex.”
from Aids Map