The U.S. government’s emphasis on abstinence in a program to fight AIDS in Africa and the Caribbean is hampering prevention efforts in the countries it aims to help, congressional investigators said on Tuesday.

President George W. Bush’s $15 billion AIDS relief plan requires that two-thirds of funds for preventing sexual HIV transmission be used to promote “ABC” programs - abstain, be faithful or use a condom.

An audit by the nonpartisan Government Accountability Office, Congress’s audit and investigative arm, found the spending requirement limited the ability of U.S. workers to address prevention priorities of the countries they serve.

“Seventeen of 20 country teams reported that fulfilling that spending requirement ... presents challenges to their ability to respond to local prevention needs,” the GAO audit said.

Three countries interviewed by GAO investigators reported that they had to cut back programs to prevent mother-to-child HIV transmission. One country reported it had to cut investment in medical and blood safety activities. Another said the ABC spending requirement had complicated efforts to address a condom shortage.

“To reserve funding to procure condoms, the team was required to cut funding for other programs in the ‘other prevention’ program area and to shift funds from the care category,” the report said.

Two-thirds of the teams also reported that ambiguous and confusing guidance made it difficult to interpret and implement the ABC program, the GAO said.

A spokesman for the State Department’s Global Aids Coordinator, which administers the program, was not immediately available for comment.

In its report to Congress, the GAO said OGAC officials acknowledged that certain components of the guidance can be confusing and said they were working to clarify them.

Critics have complained that the U.S. program leans too heavily on the promotion of abstinence and fails to place enough emphasis on condoms.

Dr. Paul Zeitz, director of the Washington-based Global AIDS Alliance, said the large earmark requirement for abstinence-only forces people on the ground to underfund critical programs.

“The Bush policy on AIDS prevention is unworkable the way it’s currently being implemented. The policy is essentially doing more harm than good,” Zeitz said in a telephone interview.

The United Nations estimates the global HIV/AIDS pandemic infects more than 30 million people in Africa. The disease has killed at least 20 million worldwide.