Lifesaving health initiatives and medical research projects have shut down around the world in response to the Trump administration’s 90-day pause on foreign aid and stop-work orders.

       In Uganda, the National Malaria Control Program has suspended spraying insecticide into village homes and ceased shipments of bed nets for distribution to pregnant women and young children, said Dr. Jimmy Opigo, the program’s director.

       Medical supplies, including drugs to stop hemorrhages in pregnant women and rehydration salts that treat life-threatening diarrhea in toddlers, cannot reach villages in Zambia because the trucking companies transporting them were paid through a suspended supply project of the United States Agency for International Development, U.S.A.I.D.

       Dozens of clinical trials in South Asia, Africa and Latin America have been suspended. Thousands of people enrolled in the studies have drugs, vaccines and medical devices in their bodies but no longer have access to continuing treatment or to the researchers who were supervising their care.

       In interviews, more than 20 researchers and program managers described the upheaval in health systems in countries across the developing world. Most agreed to be interviewed on the condition that their names not be published, fearing that speaking to a reporter would jeopardize any possibility that their projects might be able to reopen.

       Many of those interviewed broke down in tears as they described the rapid destruction of decades of work.

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