The Role of More Sensitive Helminth Diagnostics in Mass Drug Administration Campaigns
Autor: | T D Hollingsworth, Celia V. Holland, Hugo C. Turner, Rebecca F. Baggaley, Graham F. Medley |
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Rok vydání: | 2016 |
Předmět: |
0301 basic medicine
High prevalence Health economics biology business.industry 030231 tropical medicine Health impact biology.organism_classification World health 03 medical and health sciences 030104 developmental biology 0302 clinical medicine Environmental health Immunology Medicine Mass treatment Ascaris lumbricoides Mass drug administration business |
DOI: | 10.1016/bs.apar.2016.08.005 |
Popis: | Diagnostics play a crucial role in determining treatment protocols and evaluating success of mass drug administration (MDA) programmes used to control soil-transmitted helminths (STHs). The current diagnostic, Kato-Katz, relies on inexpensive, reusable materials and can be used in the field, but only trained microscopists can read slides. This diagnostic always underestimates the true prevalence of infection, and the accuracy worsens as the true prevalence falls. We investigate how more sensitive diagnostics would impact on the management and life cycle of MDA programmes, including number of mass treatment rounds, health impact, number of unnecessary treatments and probability of elimination. We use an individual-based model of STH transmission within the current World Health Organization (WHO) treatment guidelines which records individual disability-adjusted life years (DALY) lost. We focus on Ascaris lumbricoides due to the availability of high-quality data on existing diagnostics. We show that the effect of improving the sensitivity of diagnostics is principally determined by the precontrol prevalence in the community. Communities at low true prevalence ( 70%) do not benefit greatly from improved diagnostics. Communities with intermediate prevalence benefit greatly from increased chemotherapy application, both in terms of reduced DALY loss and increased probability of elimination. Our results suggest that programmes should be extended beyond school-age children, especially in high prevalence communities. Finally, we argue against using apparent or measured prevalence as an uncorrected proxy for true prevalence. |
Databáze: | OpenAIRE |
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