Don't turn away: President Mbeki addressed the Durban conference on its opening day. Credit: AP

South African President Thabo Mbeki has answered critics of his stance on the relationship between HIV and AIDS by ignoring them. Opening the 13th international AIDS conference in Durban last Sunday, he made no reference to an appeal from scientists to revise his position (see Nature 406, 15–16; 2000).

Mbeki has generated widespread concern by refusing to endorse the view that HIV causes AIDS. His decision to stick to this position — although he did refer to “HIV/AIDS” in his speech — disappointed many delegates. They were also frustrated by the lack of any mention of how Mbeki's government hopes to reduce the transmission of HIV from pregnant women to their babies.

“I'm disappointed that an opportunity was lost, both to set the record straight on the causation of AIDS, and to present a concrete plan to reduce mother-to-child transmission,” says Slim Karim, head of the HIV/AIDS unit at the South African Medical Research Council (MRC).

“Mbeki waffles on, while Rome burns,” says paediatrician Glenda Gray, director of the perinatal HIV/AIDS unit at Chris Hani Baragwanath Hospital in Johannesburg.

Mbeki focused on the well-documented impact of poverty on AIDS. “What he said is accurate; it's just what he didn't say that is the issue,” says Lynne Mofenson of the National Institute of Child Health and Development at the US National Institutes of Health. But she adds a hope that, “as he gains more insight, he will recognize that perinatal transmission is something that can be prevented, and hopefully act accordingly”.

Mbeki said his advisory panel on AIDS, which met for the second time last week (see Nature 406, 3; 2000), had agreed to report back by the end of the year on “the reliability of and the information communicated by our current HIV tests and the improvement of our disease surveillance system”.

The panel has been sharply split between those who accept the HIV hypothesis and the ‘dissidents’, led by Peter Duesberg of the University of California, who challenge it.

The meeting hammered out a broad proposal to test the accuracy of HIV testing in South Africa by comparing the results of ELISA (enzyme-linked immunosorbent assay) tests for HIV with those of other HIV tests, including the isolation of the virus.

MRC president Malegapuru Makgoba presented evidence to the panel that the percentages of false positives — the concern of the dissidents — and false negatives recorded in South African laboratories were similar to those in Western countries. Despite this, the panel agreed to test the accuracy of ELISA “in the interests of keeping the peace”, according to Karim, one of its members.

Khotso Mokhele, president of the National Research Foundation and head of the panel's secretariat, said after the meeting that he hoped the testing of screening procedures might persuade one side to “shut up once and for all”. But observers say dissidents and orthodox members are unlikely to agree on what isolation of the virus actually means.

South African HIV statistics are based on antenatal surveys analysed at laboratories across the country, using a standard protocol. Researchers would like to see testing centralized, eliminating the marginally differing levels of false negatives and positives recorded. Although panel members agree this is desirable, it would be unlikely to significantly alter estimates of HIV prevalence.

Mbeki referred in his conference speech to the need for accurate statistics rather than “estimates based on projections” — another of the dissidents' arguments — but ignored statistics on changes in mortality obtained from data compiled by his own Department of Home Affairs.

These show that deaths in South Africa among men in the 15–49 age group have increased during the past decade from 48% to 87%, while those for women in this age group have risen from 27% to 68%.

Although Mbeki did not mention the issue, mother-to-child transmission of HIV seemed set to dominate the conference. Several South African studies were presented which showed that the antiretroviral drugs AZT and nevirapine are roughly similarly effective in preventing mother-to-child transmission, even though nevirapine is only a fraction of the cost of AZT.

One outstanding issue being used by the South African government to justify not supplying either drug to pregnant women is the possibility of subsequent transmission via breastfeeding. But new evidence being presented at the conference suggests that this can be significantly reduced by early weaning, where formula feeding is possible.

http://www.aids2000.com