Evaluation of Questionnaire, Reagent Strip and Egg Count as Diagnostic Techniques for Confirming Urinary Schistosomiasis in School Children, Edo State, Nigeria

Abstract

A longitudinal study covering 55 months evaluated the three diagnostic tools used for confirmation of prevalence of urinary schistosomiasis among 1151 consented primary school pupils in 13 communities of Edo State, Nigeria. Questionnaire, reagent strip method and parasitological  examination were employed. Urine samples collected were processed using centrifugation and concentration method and deposits examined microscopically for eggs of Schistosoma haematobium. The mean  prevalence from the three diagnostic methods was 32%, as prevalence by questionnaire method was 19%, reagent strip (56%) and microscopy (21%). Age related prevalence of infection for the three methods was observed to increase with increasing age of the pupils. Sex related prevalence of infection was observed to be slightly higher in males (25%) than in females (17%) but not statistically significant (p>0.01). There was a significant relationship between questionnaire study and S. haematobium infection. Self-diagnosis with the aid of gross haematuria was a reliable diagnostic tool for S. haematobium infection, because, the difference between it and the gold standard method was insignificant. In conclusion, therefore, the reagent strip haematuria was shown to be a good indicator of S. haematobium infection that could be used repeatedly but a  combination of the three indicators had been established as a better predictor of S. haematobium infection. The sensitivity and specificity of ‘passing out blood in urine’ reading alone may be sufficient for field conditions in extremely resource –poor settings where no urine reagent strips are available. This may be used as an indicator for infection to detect
the most severely infected individuals by the Primary Health Care workers.

Keywords: Diagnostic Techniques, Urinary Schistosomiasis, School Children, Edo State, Nigeria.