Scientists turn to wastewater to track hidden HIV outbreaks

For decades, HIV has remained one of the world’s deadliest infectious diseases, with millions of cases still undiagnosed and untreated – especially in sub-Saharan Africa. But a team of Stanford researchers believes the answer to finding these hidden infections could be in an unexpected place: wastewater.

Traditional disease surveillance relies on individual testing, which is expensive and often misses those most at risk. By analyzing wastewater, entire populations can be monitored without stigma, helping people who might otherwise go undiagnosed.

With funding from the King Center on Global Development, Alexandria Boehm, Stanford Professor of Civil and Environmental Engineering, Julie Parsonnet, an Infectious Diseases clinician and epidemiologist at Stanford School of Medicine, along with a team of postdoctoral fellows, is launching the HIV Wastewater Epidemiology Initiative, a collaboration with South African scientists to explore whether wastewater surveillance can detect unrecognized HIV transmission and drug resistance. If successful, this approach could serve as a cost-effective, anonymous way to track outbreaks and target interventions in high-risk communities. With wastewater systems becoming more widespread in low- and middle-income countries, this technique could provide a scalable, cost-effective tool for monitoring diseases and shaping future public health responses.  

Through refined HIV wastewater screening methods in collaboration with the South African Medical Research Council, the initiative will focus on mapping HIV concentrations across the KwaZulu-Natal region of South Africa to identify underserved populations and monitor intervention success. Additionally, the initiative seeks to build a regional consortium to expand wastewater-based epidemiology (WBE) expertise and collaboration in southern Africa, enhancing public health monitoring and response to HIV.

The concept isn’t new – Stanford pioneered wastewater-based epidemiology (WBE) during the COVID-19 pandemic, using WBE to detect outbreaks, track new variants, and pinpoint vulnerable communities. “Over the last four years, we have shown how wastewater can be used to track a number of infectious diseases in communities including enteric, respiratory, and vector-borne viral diseases,” explains Boehm. “We were perhaps most surprised that wastewater could also provide information on community occurrence of mpox and HIV, two diseases that have disproportionately affected people living in Africa in recent years. We are excited to work closely with our partners at South African Medical Research Council to disseminate our work and translate the work to a local context where it can have an impact.” 

Now, the team is applying the same method to HIV. Early studies in California found that untreated HIV-infected individuals shed viral RNA in their urine and feces, making it possible to detect active infections at the community level. Unlike traditional testing, WBE detects multiple targets – HIV, drug resistance, and treatment levels. In South Africa, where 7.6 million people live with HIV, nearly a third of infections remain unsuppressed, fueling transmission. By identifying hotspots through wastewater, researchers hope to direct testing and treatment to the areas that need it most, potentially saving lives.

"Leveraging wastewater as a surveillance tool creates an opportunity to improve the way health systems can track and respond to HIV outbreaks, especially in underserved communities,” said Katherine Casey, faculty director of the King Center on Global Development. “This initiative embodies our commitment to supporting innovative, low-cost solutions to critical development challenges.”