Fig. 5.

Positive and negative clustering of human infection with Schistosoma haematobium in Msambweni, Kenya. Negative clustering occurs among children 6-9 years-old in the NW near the river where no cercaria-shedding snails are found (light grey with dashed border); positive clustering occurs to the east of Nimbodze pond and to the west of Maridzani pond in the non-bordered gray areas near these ponds (clustering decreasing with reduced intensity of color). Size of circles is proportional to infection density.