title: Understanding the relationship between prevalence of microfilariae and antigenaemia using a model of lymphatic filariasis infection.
abstract: Lymphatic filariasis is a debilitating neglected tropical disease that affects impoverished communities. Rapid diagnostic tests of antigenaemia are a practical alternative to parasitological tests of microfilaraemia for mapping and surveillance. However the relationship between these two methods of measuring burden has previously been difficult to interpret.
  
  
  
  A statistical model of the distribution of worm burden and microfilariae (mf) and resulting antigenaemic and mf prevalence was developed and fitted to surveys of two contrasting sentinel sites undergoing interventions. The fitted model was then used to explore the relationship in various pre- and post-intervention scenarios.
  
  
  
  The model had good quantitative agreement with the data and provided estimates of the reduction in mf output due to treatment. When extrapolating the results to a range of prevalences there was good qualitative agreement with published data.
  
  
  
  The observed relationship between antigenamic and mf prevalence is a natural consequence of the relationship between prevalence and intensity of adult worms and mf production. The method described here allows the estimation of key epidemiological parameters and consequently gives insight into the efficacy of an intervention programme.
authors.affiliation: School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK m.irvine.1@warwick.ac.uk.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Irvine
authors.affiliation: Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Post Code 00200, Nairobi, Kenya.
authors.forename: Sammy M
authors.initials: SM
authors.lastname: Njenga
authors.affiliation: School of Health Sciences, Mount Kenya University, P.O. Box 342-01000, Thika, Kenya.
authors.forename: Shamini
authors.initials: S
authors.lastname: Gunawardena
authors.affiliation: School of Health Sciences, Mount Kenya University, P.O. Box 342-01000, Thika, Kenya.
authors.forename: Claire
authors.initials: C
authors.lastname: Njeri Wamae
authors.affiliation: London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
authors.forename: Jorge
authors.initials: J
authors.lastname: Cano
authors.affiliation: London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Brooker
authors.affiliation: School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK.
authors.forename: T Deirdre
authors.initials: TD
authors.lastname: Hollingsworth
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000097:blood / Q000302:isolation & purification*; D002353:Carrier State / Q000469:parasitology; D002846:Chromatography, Affinity; D004605:Elephantiasis, Filarial / Q000453:epidemiology* / Q000276:immunology*; D005369:Filaricides / Q000627:therapeutic use*; D006801:Humans; D008842:Microfilariae / Q000302:isolation & purification*; D008962:Models, Theoretical; D015995:Prevalence; D062486:Public Health Surveillance; D014958:Wuchereria bancrofti / Q000302:isolation & purification*
chemical_list: D000947:Antigens, Helminth; D005369:Filaricides
keywords: Antigenaemia; Elimination programme; Lymphatic filariasis; Microfilaraemia; Prevalence surveys
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