Using longitudinal genetic-network study to understand HIV treatment-as-prevention

Area of Science:

• Public Health
• Epidemiology
• Virology

Background:

• The World Health Organization (WHO) recommends antiretroviral therapy (ART) for all individuals with HIV to curb transmission.
• Real-world population-level data on the effectiveness of this treatment-as-prevention strategy are limited.

Purpose of the Study:

• To evaluate the population-level effectiveness of ART in reducing secondary HIV transmission in a real-world setting.
• To assess the impact of treatment duration and viral load on HIV transmission prevention.

Main Methods:

• A longitudinal genetic-network study was conducted in Guangxi, China.
• Data from HIV patients in 2014 and newly diagnosed patients from 2015-2018 were analyzed.
• Prevention efficacy was calculated using genetic linkage to estimate secondary transmission reduction.

Main Results:

• Among 804 newly diagnosed HIV patients, 49.6% were genetically linked to baseline HIV patients.
• HIV transmission from treated patients was significantly lower (2.9%) compared to untreated patients (6.2%).
• Treatment-as-prevention showed 53.6% efficacy; over 4 years of treatment with viral load <50 copies/ml, transmission reduction was 80.3%.

Conclusions:

• The study supports the feasibility of 'treatment for all' to reduce population-level HIV transmission.
• Comprehensive HIV prevention programs are crucial for sustained public health impact.
• Adherence to long-term ART and achieving viral suppression are key to maximizing transmission prevention.