An observation of the dynamics of intestinal helminth infections in two isolated communities in south-western Nigeria.

School pupils aged 8-12 years with triple infections of Ascaris lumbricoides, Trichuris trichiura and hookworms at Iwaya, a large urban slum in Lagos State and Iworoko/Igbemo, a rural farming community in Ondo State, Nigeria, were given single dose treatment of levamisole (40 mg.). Subsequent worm accumulation was studied by egg counts per gram of faeces on the 2nd week, 3rd, 5th, 9th and 12th months after treatment. Worm infection rates and load were heavier at Iwaya. The rates of worm recruitment were also higher at Iwaya. The differences observed between Iwaya and Iworoko/Igbemo communities were due to the huge population concentration in the former, low level of hygiene, poor drainage and complete absence of municipal facilities.