[Ascariasis in Western Africa. Epidemiological review]

This paper draws, on the basis of available published reports, an outline of the epidemiological distribution of ascariasis in West Africa. This parasitic disease is easily transmitted in all humid areas which receive more than 1,400 mm rainfall every year. The endemicity pattern is typical of a contamination of the household environment. On the contrary, it is absent, with few exceptions, from a larger part of the region where drier conditions, combined with a series of specific socio-cultural factors, prevent the transmission from being anything else but sporadic. However, the author, although he recognizes that the maintenance of a short living parasite in a population is problematical under sporadic transmission conditions, warns that urban development in the future may very well result in a rapid spread of infections with ascaris.