A combination of washing hands with soap and treating water before use, reduces roundworm infection by up to 24 per cent, as compared to an 18 per cent reduction when water treatment alone is the only method, a new study has shown. A two-year study in rural western Kenya, published in PloS Medicine, examined the effects of water quality, sanation, hand washing and nutritional interventions on the rates of the intestinal worm. The study, by Tufts University, comes after a plea by the head of neglect tropical disease Dr Sultani Matendechero to the Health ministry and country departments to include hand washing in the mass deworming Kenya carries out regularly. Dr Matendechero noticed a pattern. “Immediately after deworming, the children got worms again because they were exposed to the same unhygienic conditions introduced them to the worms initially,” he said. The Health ministry estimates that worms affect about 17 per cent of children. Ascaris lumbricoides worms infections are the most common.