HHS spokesman William Pierce said the decision to cut back on the number of attendees was part of a larger program at the department to reduce travel to scientific meetings. But a confidential memo sent by Office of AIDS Research Director Jack Whitescarver to 20 NIH institute heads said in part that the decision to limit U.S. participation at the conference “was a result of the treatment the Secretary [HHS Secretary Tommy Thompson] received in Barcelona” and “HHS opinion that this meeting is of questionable scientific value.” Details from the memo were first reported by Science magazine on April 23.

At the 2002 Barcelona meeting, Thompson’s short speech to the conference was drowned out by hecklers.

Several NIH and CDC researchers who submitted lecture and poster presentations to the conference were forced to withdraw their presentations after learning of the attendance limitations, according to reports in the Washington Post and USA Today. Workshops on Third World grant applications, sustainable HIV/AIDS treatment and other topics were cancelled because NIH and HHS researchers were not available to lead the sessions, the conference organizers said.

In a letter to Thompson expressing their regret over HHS’ decision to limit travel, conference co-chairs Joep Lange, M.D., Ph.D., of the International AIDS Society and Vallop Thaineau, M.D., of Thai Ministry of Public Health offered financial assistance to help more American researchers attend the meeting.

The International AIDS Conference is considered one of the most prominent global venues for HIV/AIDS research and is attended by more than 10,000 AIDS researchers worldwide.

To read Lange and Thaineau’s letter to Secretary Thompson, go here.