Free Content

The performance of school-based questionnaires of reported blood in urine in diagnosing Schistosoma haematobium infection: patterns by age and sex

Authors: Guyatt, Helen1; Brooker, Simon1; Lwambo, Nicholas J. S.; Siza, Julius E.2; Bundy, Donald A. P.

Source: Tropical Medicine & International Health, Volume 4, Number 11, November 1999 , pp. 751-757(7)

Publisher: Wiley-Blackwell

Buy & download fulltext article:

You have access to the full text article on a website external to ingentaconnect.

Please click here to view this article on Wiley Online Library.

You may be required to register and activate access on Wiley Online Library before you can obtain the full text. If you have any queries please visit Wiley Online Library



This study investigates the performance of school-based questionnaires of reported blood in urine as an indicator of the prevalence of Schistosoma haematobium infection in schools and the presence of infection in individuals. In most schools (87%), the prevalence of reported blood in urine underestimates the prevalence of S. haematobium infection. Predictive value analysis suggests that a threshold of 30% reported blood in urine would identify most of the high prevalence schools (i.e. those with 50% or more children infected with S. haematobium). Although the prevalence of S. haematobium infection was greater in males than females, girls reported a lower prevalence of blood in urine than boys even at comparable levels of infection. Reported blood in urine in females was more specific (identifying 10% more uninfected girls than the sign in boys), but was far less sensitive (identifying less than 20% of infected girls than boys). The sensitivity of reported blood in urine was also related to age, being significantly lower in girls over 14 years of age. The proportion of infected children who reported blood in urine was also lower in schools where the prevalence of reported blood in urine is less than 30%. The results suggest that the selective treatment of children based on reported blood in urine in low prevalence schools would miss a high proportion of infected children, particularly girls. It remains unclear whether other rapid assessment techniques, such as the use of reagent strips, would offer greater cost-effectiveness.

Keywords: Schistosoma haematobium; Tanzania; diagnosis; negative predictive value; positive predictive value; questionnaires; school-based; sensitivity; specificity

Document Type: Research Article


Affiliations: 1: Wellcome Trust Centre for the Epidemiology of Infectious Disease, University of Oxford, Oxford, UK 2: National Institute for Medical Research, Mwanza Research Centre, Mwanza, Tanzania

Publication date: November 1, 1999

Related content



Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content

Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. print icon Print this page