The Trump administration has instructed organizations in other countries to stop disbursing H.I.V. medications purchased with U.S. aid, even if the drugs have already been obtained and are sitting in local clinics.
The directive is part of a broader freeze on foreign aid initiated last week. It includes the President’s Emergency Plan for AIDS Relief, the global health program started by George W. Bush that is credited with saving more than 25 million lives worldwide.
The administration had already moved to stop PEPFAR funding from moving to clinics, hospitals and other organizations in low-income countries.
Appointments are being canceled, and patients are being turned away from clinics, according to people with knowledge of the situation who feared retribution if they spoke publicly. Many people with H.I.V. are facing abrupt interruptions to their treatment.
But most federal officials are also under strict orders not to communicate with external partners, leading to confusion and anxiety, according to several people with knowledge of the situation.
U.S. officials have also been told to stop providing technical assistance to national ministries of health.
“The partners we collaborate with are in shock, and they do not know what to do because their lifesaving mission and commitment has been breached,” said Asia Russell, executive director of the advocacy group Health Gap.
Late on Sunday night, according to an email viewed by The New York Times, employees of the Centers for Disease Control and Prevention were instructed, effective immediately, to stop communicating with personnel at the World Health Organization.
They were later directed not even to be in the same meeting room — real or virtual — as W.H.O. employees or to participate in email conversations in which W.H.O. staff members are also engaged.
Some said they had been too afraid to contact colleagues they consider friends, even if just to say goodbye, and did not wish to be identified for fear of retribution.
On Monday afternoon, officials worldwide were alerted that PEPFAR’s data systems would shut down at 6 p.m. Eastern — roughly three hours after the email was received — immediately closing off access to all data sets, reports and analytical tools.
“Users should prioritize copying key documents and data,” said the email viewed by The Times.
The message prompted speculation that the program would not resume, as its future was already in question.
Some Republican senators have campaigned against PEPFAR’s reauthorization for five years, alleging that the program promoted abortions. In March, the program was renewed for one year.
Without treatment, virus levels in people with H.I.V. will quickly spike, hobbling the immune systems of the infected people and increasing the odds that they will spread the virus to others.
About one in three untreated pregnant women may pass the virus onto their babies.
Interrupted treatment may also lead to the emergence of resistant strains that can spread across the world.
One study estimated that if PEPFAR were to end, as many as 600,000 lives would be lost over the next decade in South Africa alone. And that nation relies on PEPFAR for only 20 percent of its H.I.V. budget. Some poorer countries are almost entirely dependent on the program.
“This is another domino in the devastating impact of the harmful freeze to programs, leaving lives hanging in the balance,” said Jirair Ratevosian, who served as chief of staff for PEPFAR during the Biden administration.
