HIV Diagnosis and Care Critical To Preventing Spread Of Virus To Others

Jacek Skarbinski, Interview With
Jacek Skarbinski, MD

Medical officer
Centers for Disease Control and Prevention

MedicalResearch: What is the background for this study? What are the main findings?

Dr. Skarbinski: Previous research has indicated that HIV diagnosis and viral suppression are important prevention tools that can help reduce continued transmission. However, this analysis is the first to estimate precisely what proportion of transmission can be attributed to individuals engaged in 5 stages of HIV care – including those who are unaware of their infection, those who are retained in care, and those who have their virus under control through treatment.

Our analysis shows that more than 90 percent of new HIV infections in the United States could be averted by diagnosing people living with HIV and ensuring they receive prompt, ongoing care and treatment. It also shows that the further people progress in HIV care, the less likely they are to transmit their virus.

More specifically, the analysis shows that 30 percent of new HIV infections were transmitted from people who did know they were infected, highlighting the importance of getting tested. People who had been diagnosed were less likely to transmit their infection, in part because people who know they have HIV are more likely to take steps to protect their partners from infection.

Finally, the model suggests that simply being in care can help people living with HIV avoid transmission of their virus. According to the model, people who were engaged in ongoing HIV care, but not prescribed antiretroviral treatment, were half as likely (51.8 percent) as those who are diagnosed but not in care to transmit their virus. Being prescribed HIV treatment further lowers the risk that a person will pass the virus to others. People who were successfully keeping the virus under control through treatment were 94 percent less likely than those who did not know they were infected to transmit their virus. But, previous national estimates have indicated that just 30 percent of people with HIV have reached this critical step in care.

In short, this analysis validates the nation’s current prevention efforts, reminding us that HIV diagnosis and care improves the lives of people living with HIV and that it is also critical for reducing the chances of transmitting the virus to others.

MedicalResearch: What should clinicians and patients take away from your report?

Dr. Skarbinski: Both patients and clinicians should know that this is the latest in a growing body of evidence that prevention of new infections depends on reaching people who are HIV-positive with testing, care and treatment.

Once people know they have HIV, they take steps to prevent transmission to their partners. In fact, our study shows a 19 percent drop in the transmission rate after diagnosis – largely because people who found out they had HIV decreased the number of times they had sex without a condom with a negative partner.

After diagnosis, simply being in care can help prevent transmission by giving people living with HIV tools and information they can use to protect themselves and their partners. In addition to treatment, HIV care should include risk reduction counseling, STI screening and treatment, treatment for mental health and substance use disorders, and other prevention services.

The ultimate goal is to provide ongoing care and treatment so all people living with HIV can achieve viral suppression. U.S. guidelines now recommend that everyone diagnosed with HIV should get treatment, regardless of their viral load count. According to our model, people who are virally suppression are 94 percent less likely to transmit their virus than people who are unaware of their infections.

Bottom line: improving the health of people living with HIV is critical for both those with HIV and for those at risk for HIV.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Skarbinski: The study published today is the just the first in a series. Our next step is to expand the current model and assess the potential impact and costs of different interventions that target different steps of the HIV care continuum. The ability to compare the impact and associated cost of combinations of interventions, such as expanded HIV testing and improved retention in care, on prevention will be critical to guiding public health programs and improve HIV prevention. Moreover, we are also expanding the model to better understand patterns of transmission among particular sub-groups, such as men who have sex with men, to help guide prevention efforts.

You may also view the brief, 60-second video the CDC has put together highlighting the key data from the manuscript and putting them into the context of the nation’s prevention efforts here:

Jacek Skarbinski, Eli Rosenberg, Gabriela Paz-Bailey, H. Irene Hall, Charles E. Rose, Abigail H. Viall, Jennifer L. Fagan, Amy Lansky, Jonathan H. Mermin. Human Immunodeficiency Virus Transmission at Each Step of the Care Continuum in the United States. JAMA Internal Medicine, 2015; DOI: 10.1001/jamainternmed.2014.8180