Hematuria and dysuria in the self-diagnosis of urinary schistosomiasis among school-children in Northern Cameroon.

The present study was designed to assess the value of self reported hematuria and dysuria in the diagnosis of urinary schistosomiasis at the individual level. A sample of 964 school children of grade 5 and 6 from 15 schools of the French speaking educational system in the Sudano-sahelian zone of northern Cameroon were submitted to a questionnaire related to hematuria and dysuria, and provided a urine sample each. The urine samples were processed using the dip stick and sedimentation methods, and the degree of microhematuria and oviuria determined. In all 964 questionnaires were collected, 843 urine samples examined for microhematuria and 871 for oviuria. The percentage of children reporting hematuria increased with the degree of microhematuria and the intensity of infection. Among the various indicators of urinary schistosome infection, microhematuria had the highest sensitivity (76%), followed by self reported hematuria or dysuria (65%), and dysuria (52%). The specificity was highest for self reported hematuria, and lowest for self reported hematuria or dysuria. The efficiency of self reported hematuria or dysuria increased with the intensity of infection and was highest (100%) for heavy infections (> 400 eggs/ml g urine). We advocate the use of self reported hematuria or dysuria for the assessment of S. haematobium at the individual level.