RESUMEN
Four thousand immigrant schoolchildren were screened by using a concentration method on a single faecal specimen for intestinal helminths; 1,468 (37%) were positive. Carriage rates were highest (51%) in children from the West Indies, in whom trichuris (75% of carriers) and ascaris (40% of carriers) predominated; carriage of two or more species was common (36% of carriers). Carriage of worms was low in children from Kenya (16%) and Uganda (7%). Children from South-east Asia, predominantly from India and Pakistan, had carriage rates between 30 and 40%; girls and boys from Pakistan differed significantly in their carriage patterns of hook-worm (commoner in boys) and hymenolepis and ascaris (commoner in girls).Five salmonellas were found, two of which were Salmonella typhi, and five Shigella sonnei were isolated. No isolates were made of Vibrio cholerae (classical or El Tor biotypes) from 590 South-east Asian children.