Age and sex distribution of infections with Entamoeba histolytica and Giardia intestinalis in the Lagos population.

Stool samples were collected from 2,099 persons and examined for parasites: 9.5 percent were infected with Entamoeba histolytica, 7.9 percent were infected with Giardia intestinalis and 15.5 percent were infected with Iodamoeba butschlii. The infections with E. histolytica and I. butschlii occurred more frequently in females than in males and adults were also more frequently infected than children. Infection with G. intestinalis, on the other hand, was more prevalent in males than in females and children were more frequently infected than adults with the highest incidence of infection (13.8 percent) in the age-group 1-5 years.