The association of endemic elephantiasis of the lower legs in East Africa with soil derived from volcanic rocks

Endemic elephantiasis of the lower legs in Ethiopia, which raches a maximun of 86.7 per 1000 adults in affected areas, is related to the distribution of red clay soil derived from volcanic rocks, particularly basalt. Prevalence falls rapidly on leaving these areas. This observation has been tested in regions of non-filarial elephantiasis reported in Kenya and north-western Tanzania and further investigated in volcanic areas of Rwanda where the disease had not previously been reported. The same relationship is found to occur in these areas. The limitation to the lower legs of the barefooted section of the farming community suggests that the actiological factor or factors enter by the feet (AU)