MRC PhD students

Human helminthiasis in the context of the HIV/AIDS epidemic in the Western Cape.

Supervisor: Dr JE Fincham

Impairment of nutrition by intestinal parasites has been clearly established. Intestinal parasites and HIV/AIDS are often co-endemic under conditions of poverty in the Western Cape province of South Africa, as well as elsewhere in the country. The extent and severity of helminthiasis has been established at more than 60 schools or creches, as well as in groups of HIV-positive and HIV-negative adults in the Western Cape by the Helminth Group of the Nutritional Intervention Research Unit (NIRU) of the MRC.

There is increasing evidence of interaction between helminthiasis and HIV/AIDS. Worm infections seem to imbalance the immune system by down‑regulating the immune response needed to combat infection by HIV and slow progression to AIDS. The efficacy of some proposed vaccines might also be impaired if people are infected with HIV and co-infected with worms.

The scope of the PhD study includes the following:

• Estimation of the possible extent of co‑infection by helminths (specifically Ascaris, Trichuris, Taenia solium and Enterobius) and HIV in school-age children and adolescents in the Western Cape.
• Description of operational research which shows that implementation of school-based deworming would be feasible in metropolitan Cape Town if it is based on participatory health care.
• Definition of obstacles to the use of regular mass deworming as a means to modulate the immune profile against infection by HIV, as well as for public and child health; and recommendations on how to eliminate them and cut costs.
• In the Western Cape, regular school-based deworming would be feasible and there is evidence that it could alter the immune profile in a beneficial way in terms of combating infection by HIV (and probably other bystander diseases). There is also evidence that regular deworming might improve the efficacy of anti‑HIV-vaccination given before sexual activity starts, and might improve the efficacy of HIV-vaccine trials.