The 'small spleen' in malaria.

A cardinal feature of malaria, splenomegaly, is usually absent in adult patients who have already suffered from falciparum malaria or who are natives of an endemic falciparum zone. This is an attribute of the past episode of clinical or sub-clinical malaria which usually results in regression of the splenic size to below-normal. An ultrasonographic evaluation of spleens was done in 90 healthy adult males, who had suffered from vivax (n = 28) or falciparum (n = 25) malaria in the past, except the controls (n = 22) and natives from an endemic falciparum area (n = 15) who never suffered from malaria. Their ultrasonographic details of spleens, including the size, were compared. Besides other conspicuous differences in the ultrasonographic picture, spleen size was found significantly decreased (p < 0.01) in the group who had been affected by P. falciparum malaria; the smallest measured 7.8 cms. In P. vivax group the decrease was not significant (p < 0.1), but was highly significant in inhabitants of endemic falciparum region (p < 0.001). The present study establishes the 'Small Spleen' and looks at echotexture pattern variations thereof for the first time.