|
|
||||||||
We aggregated published data from field studies documenting prevalence of Schistosoma haematobium infection and bladder pathology determined by ultrasonography or hematuria detected by reagent strip, questionnaire, or visual examination. A mathematical expression was used to describe the associations between prevalence of pathology/morbidity and infection. This allows for indirect comparison of these methods, which are rarely used simultaneously. All four methods showed a similar, marked association with infection. Surprisingly, ultrasound revealed higher prevalences of pathology in schools than in communities with the same prevalence of infection, implying a need for age-related cut-off values. Reagent strip testing yielded a higher prevalence than questionnaire, which in turn was higher than by visual examination. After correction for morbidity due to other causes, a consistent ratio in prevalence of hematuria of 3:2:1 resulted for the three respective methods. The simple questionnaire approach is not markedly inferior to the other techniques, making it the best option for field use.
Received November 30, 2003. Accepted for publication January 31, 2004.
Acknowledgments: We thank Christopher Hatz, Dirk Engels, Bruno Gryseels, Katja Polman, Nico J. D. Nagelkerke, and Gerard J. J. M. Borsboom for critical comments and methodologic support.
Financial support: This study was performed as part of the multidis-ciplinary program "Model-Based Decision Support for Schistosomiasis Control in Ghana, Mali and Senegal" supported by The Netherlands Foundation for the Advancement of Tropical Research (WOTRO), and was also supported by the Department of Communicable Diseases Control, Prevention and Eradication, World Health Organization (Geneva, Switzerland).
Authors address: Marieke J. van der Werf and Sake J. de Vlas, Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, PO Box 1738, 3000 DR Rotterdam, The Netherlands, Telephone: 31-10-408-7714 and 31-10-408-7985, Fax: 31-10-408-9449, E-mails: vanderwerfm{at}kncvtbc.nl and s.devlas{at}erasmusmc.nl.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |