Urinary schistosomiasis: testing with urine filtration and reagent sticks for haematuria provides a comparable prevalence estimate

Abstract

The relationship between school prevalence rates of urinary schistosomiasis, measured by urine filtration and by reagent sticks detecting haematuria, was investigated in nine primary schools in Tanzania. The aim of the study was to provide a methodological tool to compare results from studies that used these two different diagnostic techniques. A strong correlation was found between both measures (r = 0.96, P < 0.0001), and the equation of this linear relationship could be used to extrapolate the parasitological prevalence rate on the basis of the reagent stick testing, or the reverse. A review of the available literature indicated that the relationship holds true for certain settings, mainly in East Africa, but not for others, and it is therefore likely to be setting-specific. The same data demonstrated also a good relationship, at school level, between the mean school parasitological intensity and the sensitivity of the reagent sticks. A comparative testing of two different reagent stick brands (Hemastix and Combur 9) on 320 samples showed that the latter detected about 1.2-times more haematuria positives, and that this had also to be taken into account when aiming for a comparison of different techniques.