At the peak of an outbreak, a disease appears to be everywhere you look, so it makes sense to test large swaths of the population. Near the end of an outbreak, you have to go looking for the remaining pockets of disease to keep it from re-establishing itself.
“You get to a point where testing is no longer cost-effective and no longer yielding great results,” explained Susie Welty, MPH, a senior program manager at IGHS. “You’ve flushed out the biggest problem and now you have to go after the remaining cases.”
Incredibly, we are entering that phase of the HIV epidemic, and UCSF is continuing to lead the way.
In the last several years, it has become possible to learn, using blood tests, whether an HIV-positive person contracted the virus in the last 6–12 months. (UCSF faculty contributed to the research that made such testing possible.) In half of all countries that have begun to use the technology, IGHS’s Global Strategic Information group is training government health officials to provide the test as appropriate in public health clinics, to track the results on a live interactive dashboard and to tailor public health efforts to high-risk groups and regions.
IGHS is doing this work in Namibia, Zambia, Kenya, Uganda, Malawi, Vietnam, Cambodia and Thailand. Principal investigator George Rutherford, MD, and program manager Welty launched these partnerships at the end of 2018 with support from the Centers for Disease Control and Prevention (CDC).
Identifying recent cases guides prevention efforts and monitors their effectiveness; it can also prevent individuals at high risk from contracting the disease. If a partner of a newly infected person is still HIV-negative, they can be started on pre-exposure prophylaxis and remain negative. The process can also work in the other direction: A newly infected person can point back to the person who likely gave them the virus so that person can be started on treatment, reducing their chance of passing it on to anyone else. “Contact tracing is really Epidemiology 101– it’s what the San Francisco Department of Public Health is doing right now with COVID-19,” Welty explained.
Data-use agreements allow UCSF to use the data flowing through the recency dashboards to feed research publications on how HIV is spreading in Africa and Asia. It’s too early to ferret out any new patterns in how the disease is being transmitted, but Welty says she has been struck by how many teenage girls figure among the recent infections. They are seeking care, and being tested, when they become pregnant. Their infected partners are often older men with whom they have had transactional sex.
IGHS won the CDC’s competitive grant to leverage HIV infection recency testing in heavily affected countries thanks to its track record with large HIV surveillance efforts – including Namibia’s country-wide survey, similar work through the MeSH Consortium (funded by the Gates Foundation) and a pilot of the recency program in Malawi.