Evaluation and Validation of the Questionnaire Approach for the Diagnosis of Urinary Schistosomiasis amongst Nigerian School Pupils

Abstract

Urinary schistosomiasis is endemic in some parts of Cross River State, in Nigeria. Due to the prohibitive cost of diagnosis and the focal nature of the disease, endemic areas cannot be easily delineated for control operations. In this study, we report the outcome of our assessment of the newly introduced questionnaire approach in the diagnosis of urinary schistosomiasis amongst 5,453 pupils and also validated its performance among a subset of 310 pupils in Biase Local Government Area. The questionnaire which enquired whether pupils had urinary schistosomiasis or blood in their urine in the preceding month, was administered by class teachers to the pupils. Urine samples collected for the validation of the questionnaire diagnosis was also examined using dipsticks (by teachers and the research team) and for the presence of ova of Schistosoma haematobium. There was a strong positive correlation between the pupil's knowledge of schistosomiasis as a disease and the reported presence of blood in urine (r=0.96) although the later was a better indicator of the disease. The questionnaire technique (blood in urine) gave a comparable sensitivity (85.8%), specificity (81.4%), positive and negative predictive values (96.6% and 47.9%) to the dipstick test with values of 93.6%, 88.4%, 98% and 69.1% respectively. Age had a statistically significant influence on the results of the different survey techniques (P < 0.05, P < 0.01) unlike sex (P > 0.05). Teachers were able to detect haematuria with a high level of accuracy. We found this approach to be simple, cost-effect and reliable and have recommended its usage in other endemic settings with large land mass and dense populations like Nigeria.

Key Words: Schistosomiasis, Diagnosis, Questionnaire, Cross River , Nigeria.

Mary Slessor Journal of Medicine Vol.4(1) 2004: 63-71