HIV patients on treatment do not transmit the virus through not using a condom

​Neither gay men nor heterosexual people with HIV transmit the virus to their partner, provided they are on suppressive antiretroviral treatment. This has been demonstrated in the results of the world’s largest study of people with HIV who have had condomless sex with their HIV negative partners.

The extensive PARTNER study has monitored 888 couples from 14 different European countries, in which one of the partners was on effective treatment for HIV. Of the 888 couples, 548 were heterosexual and 340 were gay men. All the couples had sex regularly without using a condom. They have now been monitored for several years and not one instance of transmission of the virus has been recorded. The results have just been published in the prestigious Journal of the American Medical Association.

“The results clearly show that early diagnosis of HIV and access to effective  treatment are crucial for reducing the number of new HIV cases. As soon as a patient with HIV ​is on treatment with a suppressed viral load, the risk of transmission becomes minimal,” said Prof. Jens Lundgren from Rigshospitalet, senior author of the study and head of CHIP (the Centre for Health and Infectious Diseases), who has coordinated the study with Prof. Andrew Phillips and Dr. Alison Rodger from University College London. 

No HIV transmission between couples

In the follow-up period, a total of 11 HIV-negative partners were infected with HIV. Led by Prof. Anna Maria Geretti, researchers from the University of Liverpool undertook phylogenetic analyses of the 11 new HIV cases and their partners’ virus. The HIV virus can be divided into several sub-groups, each with its own genetic characteristics, and this makes it possible to see whether the virus is genetically similar to a partner’s. In all cases the results showed that the virus came from someone other than the partner under treatment. 

More data on the way

Gay couples in the study will continue to be monitored for three more years to obtain even more data in this area for anal sex.. 

“It’s vital that we continue follow-up in order to establish more accurate assessments of the risks; especially men who have sex with men.. Although we didn’t find any instances of transmission in our study, we cannot entirely rule out the risk,” said Alison Rodger. 

The results of the second part of the PARTNER study, which will only monitor gay men, are expected in 2018.


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