Soil-transmitted helminthiasis in Selangor, Malaysia.

A survey of 25,246 Malay, Chinese and Indian children and adults ranging from birth to over 60 years of age, of both sexes, from 4 types of communities with different conditions of environmental sanitation and socio-economic status revealed an overall incidence of infection with soiltransmitted helminths of 39.6 percent. The incidence of soil-transmitted helminthiasis was highest among rural rub ber estates, followed closely by the urban slums or squatter areas and incidence of infection was low in the semi-rural new villages and the urban flats. The commonest helminth in all these areas was Trichuris trichiura and the commonest type of helminthic infection was mixed infections with Ascaris and Trichuris. Infection was most prevalent among Indians, followed closely by Malays. Chinese generally had lower incidences ofinfection. Soil-transmitted helminthiasis was also more prevalent among the younger age groups, starting from toddlers to 9 years and rising to a peak in the 10-19 years age group. Elderly people (60 years and above) from the squatter areas and some of the estates, new villages andflats also had a higher incidence of infection than the older adults (30-59 years). Malay and Indian children (under 15 years of age) having a higher overall incidence of injection also tended to have higher degrees of infection, as estimated by egg counts. There was no signijz'cant differences in the distribution of