A medical group says the World Health Organization is grossly underestimating the re-use of syringe needles and unsafe medical practices as a major cause of HIV/AIDS transmission in Africa. But U.N. officials deny the claim.

The International Association of Safe Needle Technology says some 30 percent of new cases of AIDS in Africa are attributable to the re-use of needles and to other poor medical practices.

That is far more than the 2.5 percent estimated by the WHO.

The group's director, Lillian Salerno, told reporters at the international AIDS conference held in Kenya's capital this week that the WHO has "focused on the role of sexual transmission in Africa to the point of excluding virtually all other causes. This is not only misleading," she said, but "it is also dangerous."

The group has called for increased protection for African health care workers. The group wants more attention paid to the role of health care practices in the transmission of HIV/AIDS.

But a pharmacist working in South Africa for Doctors Without Borders, Marta Darder, says the 30 percent figure is exaggerated.

"My concern when I hear these kind of strong statements in a conference like this is that it might deviate attention of what to me are the key burning issues now to tackle the AIDS pandemic in Africa particularly, which is very much related to the extremely inequitable access to anti-retroviral therapy as part of a comprehensive package of care," she said.

Other issues according to Ms. Darder include the high prices of AIDS drugs, the lack of political commitment from governments to supply those drugs because of patent issues and a shortfall of funding needed to care for those living with HIV/AIDS.

The executive director of UNAIDS, Dr. Peter Piot, also disputes the needle association's findings.

"Well, 30 percent is definitely off the wall as a figure," he said. "What we have to do is that we have to make sure that with this new treatment program, offer the possibility also to make sure there is better hospital hygiene, injections are only used when necessary, etc."

He concedes unsafe medical practices are a factor in HIV transmission, but not to the extent that the group portrayed.