In 2008, the AIDS epidemic in South Africa was out of control. Now the country has won high praise from world AIDS experts for its response at a time when the Ebola virus is spreading in West Africa, NYTimes reports.

But experts say much of that progress is in peril.

South Africa has 2.4 million people on antiretroviral drugs — far more than any other country, with 100,000 more being added each month. Just 250 nurses were trained to prescribe them five years ago. Now 23,000 are, based on figures from 2013, the most recent available, according to NYTimes. Five years ago, 490 clinics gave out those drugs; now 3,540 do.

Though few Americans or South Africans realize it, South Africa owes much of its success to a single U.S. program, the President’s Emergency Plan for AIDS Relief, or Pepfar, started in 2003 under President George W. Bush. More than $3 billion poured into South Africa under the program, with the money going mostly for buying drugs, training doctors, and building clinics and labs.

Life expectancy has increased by almost 10 years, mother-to-child transmissions dropped by 90 percent and new infections have dropped by a third.

“South Africa takes this very seriously and has made major, major progress,” said Michel Sidibé, the executive director of UNAIDS, the United Nations agency fighting the disease.

But the Pepfar aid pipeline is drying up as the program shifts its limited budget to poorer countries. The South African government must find hundreds of millions of dollars, even as its national caseload grows rapidly.

The country has six million people infected with AIDS and 370,000 new infections a year, NYTimes reports. That’s seven times as many new infections as the U.S., which has six times more people. According to a new survey, teenage South African girls are becoming infected at alarming rates and condom use is dropping.

Still, Dr. Aaron Motsoaledi, the national health minister, says he is confident South Africa will find the money and the political will to fight on.