Research assistants and technicians from the University of Ghana perform basic skin prick tests on school children in Accra, Ghana to test for sensitivities to dog, cat, dust mites, grass pollen, peanuts, and cockroach allergens. The results have shown that children in wealthier homes have higher rates of allergies and asthma than poorer children. The leading theory is that higher rates of helminth (parasite) infections among poorer children are affecting the immune system in a way that offers protection from allergies and asthma. The study aims to find out what the worms are doing, isolate the beneficial effect and replicate it.