HIV Transmission Rates Decreased With Prompt Diagnosis and Treatment

Although viral suppression has become increasingly prevalent in people with HIV in recent years, and the rates of new infections and transmissions have been decreasing, there are ways to accelerate this progress, according to results of a study published in the Centers for Disease Control’s Morbidity and Mortality Weekly Report.

An estimated 1.1 million Americans had HIV in 2016, and 38,700 of these cases were new infections. Data for the model used to estimate transmission rates along the HIV continuum of care were obtained from National HIV Behavioral Surveillance and National HIV Surveillance System data.

Among the patients included in the model, methods used to prevent transmission of HIV included knowing infection status, rapid treatment initiation after diagnosis, treatment adherence, and use of antiretroviral therapy (ART). For those using ART, viral suppression is now commonly achieved within 6 months, enabling patients to live long, healthy lives with effectively no risk of transmitting HIV to sexual partners.

The overall rate of HIV transmission in 2016 was 3.5 per 100 person-years. Transmission rates along the HIV continuum of care were 16.1 per 100 person-years for those who were acutely infected with HIV but unaware, 8.4 for those non-acutely infected and unaware, 6.6 for those aware of infection but not receiving care, 6.1 for those receiving care but who were not virally suppressed, and 0 for virally-suppressed individuals taking ART. The percentage of all transmissions generated by each of these groups in the continuum were 4.0%, 33.6%, 42.6%, 19.8%, and 0%, respectively.

Limitations to this study included limited data on behaviors as a result of self-reporting, lack of data on viral suppression in reducing transmission during drug use, lack of data on the link between awareness of HIV infection and viral suppression by age, a smaller sample size, and a model that conservatively restricted reductions in transmission as a result of low viral load.

Researchers concluded that “[p]roviders should screen patients for HIV infection at least once and test some patients more frequently; rapidly link, engage, or re-engage patients into comprehensive HIV care; and encourage patients to sustain viral suppression for their own health and because of the tremendous prevention benefits. In addition, many persons with HIV infection find it important to know that maintaining viral suppression prevents sexual transmission to partners and sharing this knowledge more generally might decrease the stigma associated with HIV infection and help engage patients in consistent care.”

Reference

Li Z, Purcell DW, Sansom SL, Hayes D, Hall HI. Vital Signs: HIV transmission along the continuum of care — United States, 2016. MMWR Morb Mortal Wkly Rep. 2019; 68(11):267-272.