This could benefit millions of people across the world.
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“I’m not here to suggest (that) the risk isn’t very low”, he said.
‘As soon as a patient with HIV is on treatment with a suppressed viral load, the risk of transmission becomes minimal’. But the study said it’s unlikely this risk is above 0.3 percent per year for straight couples or 0.7 percent per year for gay male couples.
Previous studies have been nearly exclusively in heterosexual people who still reported high rates of condom use.
“Zero transmissions from over 58,000 individual times that people had sex without condoms”. This includes follow-up of people having anal sex without condoms. The study was conducted in Europe.
Alison Rodger from University College London and colleagues evaluated the rate of within-couple HIV transmission during periods of sex without condoms and when the HIV-positive partner had HIV-1 RNA load less than 200 copies/ml.
Follow-up included routine sexual health checks (including HIV testing for the negative partners) and each participant also completed sexual history questionnaires. “In all cases, the results showed that the virus came from someone other than the partner under treatment”, lead study author Anna Maria Geretti, a clinical infection, microbiology and immunology professor at the University of Liverpool Institute of Infection and Global Health, said in the release.
Therefore, there were no transmission cases found between any of the couples when the HIV-infected partner was on suppressive ART. Instead, they’d contracted HIV by having sex outside their relationships; 33 percent of HIV-negative gay men reported having condomless sex with other partners compared to 4 percent of heterosexuals.
“We think the risk from condomless anal sex is low, but we need to ensure we have a couple years of follow up to give more precise estimates”, she said.
There were, however, 11 cases in which a partner who was HIV negative at the start of the study became infected with the virus that causes AIDS.
Researchers say the results are simple to understand.
Prescribing HIV drugs to gay men and heterosexuals does stop them transmitting the virus to their partner, new evidence has confirmed.
The results raise the question of whether transmission with an undetectable viral load is even possible.
The results challenge criminalisation in many countries, including the United States, based on assumptions of risk that the study disproves.
The new study is very reassuring but has some limitations, said Dr. Eric Daar, an HIV expert who wrote an editorial accompanying the new study.
However, they cautioned, more follow-up is needed.
Activist Sean Strub, from the SERO project said HIV criminalisation has created a viral underclass in the law “further burdening a disenfranchised community, putting a disproportionate share of the shared responsibility for preventing sexually-transmitted infections on one party, and discouraging people at risk from getting tested for HIV”.
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“Although these results can not directly provide an answer to the question of whether it is safe for serodifferent couples to practice condomless sex, this study provides informative data (especially for heterosexuals) for couples to base their personal acceptability of risk on”, said the study, led by Alison Rodger of University College London.
