HIV drugs help reduce risk of infection to near zero: study

By Cara Murez HealthDay Reporter

MONDAY, July 24, 2023 (HealthDay News) — People who take antiretroviral therapy to treat HIV and have low but detectable levels of virus have virtually no risk of transmitting the virus to others, according to a new research review.

The researchers looked at eight studies involving more than 7,700 couples in which one person was HIV-positive and the other was not. The studies were carried out in 25 countries and reviewed by teams from the Global Health Impact Group and the World Health Organization.

Their review, published July 22 in The Lancet, found that people with an HIV viral load below 1,000 copies/mL have virtually no risk of transmitting the virus to their sexual partners. Previous studies have not been able to confirm an absence of transmission risk above a much lower number – 200 copies/mL.

This review also reinforced previous studies showing that people with undetectable virus levels have no risk of transmitting HIV to sexual partners.

Only two of the 320 sexual transmissions of HIV documented in the study involved a partner with a viral load below 1,000 copies/mL. For both, viral load tests were performed at least 50 days before transmission.

At least 80% of the transmissions observed in the study involved an HIV-positive partner with a viral load greater than 10,000 copies/mL.

“These results are important because they indicate that it is extremely rare for people who maintain low levels of HIV to pass it on to their sexual partners,” said the lead author. Dr. Laura Broylesof the Global Health Impact Group in Atlanta.

“Essentially, this finding may promote the expansion of alternative viral load testing modalities that are more feasible in resource-limited settings,” she said in a press release. “Improving access to routine viral load testing could ultimately help people living with HIV live healthier lives and reduce transmission of the virus.”

Global efforts are underway to achieve undetectable viral loads through the use of antiretroviral therapy (ART) and to reinforce the importance of decriminalizing HIV and reducing stigma and discrimination for people living with the virus.

Without ART, people living with HIV can have a viral load of 30,000 to over 500,000 copies/mL, depending on the stage of infection.

A new WHO guidance note is released alongside the research review.

This guidance note provides up-to-date advice on prevention and testing for policy makers, public health professionals and people living with HIV. It aims to support global efforts to achieve undetectable viral loads through antiretroviral therapy for all people living with HIV and to prevent transmission to their sexual partners and children.

The authors investigated the risk of transmission by searching databases for studies published between January 2000 and November 2022 on the sexual transmission of HIV at different viral loads.

Laboratory testing of plasma samples is the most sensitive, but the results also support simpler testing approaches, such as using dried blood spot samples.

The results do not apply to mother-to-child transmission of HIV, where the exposure is of much greater duration and intensity. Differences also exist in how the virus is transmitted from mother to child compared to sexual transmission. The researchers said ensuring pregnant and breastfeeding women have undetectable viral loads throughout the exposure period is key to preventing new childhood infections.

This research was funded by the Bill & Melinda Gates Foundation.

SOURCE: The Lancetpress release, July 23, 2023

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