Cust said the losses went beyond money. Providers lost the systems that kept prevention, testing and treatment running for people at the highest risk of HIV.

"For the first time, we can put real numbers on what the U.S. funding withdrawal actually did for those most vulnerable to HIV and at the forefront of the epidemic," he said.

"In the organizations involved, services used successfully to tackle the HIV epidemic in sub-Saharan Africa fell by between a half and two-thirds, largely remaining there through March 2026. The safety net that was supposed to preserve lifesaving treatment did not hold. The services and community trust that took decades to build were dismantled overnight."

Who lost care?

The four organizations serve what health agencies call key populations: men who have sex with men, female sex workers, people who inject drugs, prisoners and transgender people.

In Uganda and Zimbabwe, many of these groups face criminalization. Stigma and legal barriers limit their access to ordinary public health services, so community-based care from NGOs is often their only option.

One of the study organizations, the Center for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, has already seen the human cost. Its key populations program technical director, Byrone Chingombe, said: "The vulnerable populations we take care of do not trust our services anymore. They say, 'You went away without any notice, and you were not available, you left us with nothing.'"

Cust cautioned that the findings should not be stretched beyond what the data support — the study covers four providers, not the entire region. But he said the pattern likely extends to other organizations that relied heavily on USAID contracts for lifesaving services.

Why didn't the humanitarian waiver protect treatment?

After the stop-work orders, the U.S. issued a humanitarian waiver meant to allow lifesaving services to continue. Treatment still declined after the waiver took effect.

The study suggests a reason: dismantling the funding and drug-distribution channels limited the waiver's ability to restore the staff, supplies and delivery systems that care depends on.

"The U.S. released a waiver that said lifesaving services could continue working, and, by implication, would continue to receive funds. That should have protected HIV treatment," Cust said. "However, because they dismantled the apparatus to deliver the funding and distribute the drugs, the waiver had limited impact on USAID-funded organizations. It's a case of actions speaking louder than words."

What happens next?

Cust identified three urgent needs: protecting HIV services for the most vulnerable populations, which local health systems are unlikely to replace on their own; strengthening emergency transition funding; and building stronger, more inclusive domestic services.

"The most vulnerable populations have lost a lifeline, and the urgent focus needs to be on protecting services for key populations that are crucial to fighting HIV," he said. "Not all organizations serving these populations have survived, and those still hanging on desperately need renewed funding."

The study appears as Henry Cust et al., "HIV service delivery after the PEPFAR and USAID HIV funding withdrawal in Uganda and Zimbabwe: an interrupted time-series study," in The Lancet Global Health (2026), DOI: 10.1016/j.langlo.2026.104061.