Sir

Although I entirely endorse the stand taken by the authors of the Durban Declaration1, I think that HIV is the principal, rather than the sole, initiating factor of the current world pandemic of AIDS. I believe this for the following reasons.

First, from my experience of secondary or acquired immune deficiency in treated lymphoma patients who are HIV negative and in patients who have chronic graft- versus-host disease after a transplant, HIV is not the only mechanism for adults developing the clinical syndrome. Second, external influences such as immune stimuli can modify progression, as demonstrated when haemophiliacs given recombinant factor VIII have a slower loss of CD4 lymphocytes than those who receive immunogenic serum protein containing factor VIII concentrates2. Third, poor nutritional status identified on the basis of low vitamin A levels is associated with increased viral shedding3. This augments HIV perinatal transmission rate in breastfeeding African women4 and non-breastfeeding US women5. Fourth, general genital hygiene6, underage sexual activity and circumcision7 all affect the risk of acquiring HIV infection.

It is appalling that, as Dorritie states in Correspondence8, there may be a right-wing political agenda behind the campaign claiming AIDS is not caused by HIV. Nevertheless, other social factors are involved in the African aspects of this epidemic, such as Johannesburg's high incidence of rape, the myth that raping a virgin can cure AIDS, and the high level of non-HIV sexually transmitted diseases in sub-Saharan Africa9.

As a consequence, there are benefits to be gained from President Mbeki's call for scientists to address the nature of AIDS and its links to HIV in an African setting. Such an investigation could well conclude that investments such as educating young men in the basics of sexual hygiene, providing nutritional supplements for pregnant women and treating mastitis10 might produce greater gains than spending money on antenatal treatment with antiretroviral drugs.