Imperial College London
Alternate

Professor Sir Roy Anderson FRS, FMedSci

Faculty of Medicine, School of Public Health

Professor in Infectious Disease Epidemiology
 
 
 
//

Contact

 

roy.anderson Website

 
 
//

Assistant

 

Mrs Clare Mylchreest +44 (0)7766 331 301

 
//

Location

 

LG35Norfolk PlaceSt Mary's Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Giardina:2019:10.1371/journal.pntd.0007514,
author = {Giardina, F and Coffeng, LE and Farrell, SH and Vegvari, C and Werkman, M and Truscott, JE and Anderson, RM and de, Vlas SJ},
doi = {10.1371/journal.pntd.0007514},
journal = {PLoS Neglected Tropical Diseases},
title = {Sampling strategies for monitoring and evaluation of morbidity targets for soil-transmitted helminths},
url = {http://dx.doi.org/10.1371/journal.pntd.0007514},
volume = {13},
year = {2019}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - BackgroundThe current World Health Organization (WHO) target for the three major soil-transmitted helminth (STH) infections is to reduce prevalence of moderate-to-heavy infections to below 1% by 2020. In terms of monitoring and evaluation (M&E), the current WHO guidelines for control of STHs recommend evaluation of infection levels in school-age children (SAC) after five to six years of preventive chemotherapy (PC), using the standard Kato-Katz faecal smear. Here, we assess the predictive performance of various sampling designs for the evaluation of the morbidity target.Methodology/Principal findingsUsing two mathematical models for STH transmission and control, we simulate how the number of villages and SAC sampled affect the ability of survey results in sentinel villages to predict the achievement of the morbidity target in PC implementation units (e.g. districts). As PC is stopped when the prevalence of infection in SAC in sentinel villages is less than 1%, we estimate the positive predictive value (PPV) of this indicator for meeting the morbidity target in the whole district. The PPV varies by species and PC strategy, and it is generally higher in areas with lower pre-control prevalence. Sampling a fixed number of SAC spread out over 10 instead of 5 sentinel villages may increase the PPV by up to 20 percentage points. If every SAC in a village is tested, a higher number of villages may increase the PPV by up to 80 percentage points. Increasing the proportion of SAC tested per village does not result in a relevant increase of PPV.Conclusions/SignificanceAlthough the WHO guidelines provide a combined strategy to control the three STH species, the efficacy of PC strategies clearly differs by species. There is added value in considering more villages within implementation units for M&E of morbidity targets, the extent varying by STH species. A better understanding of pre- and post-control local STH prevalence levels is essential for an adequate M&E strat
AU  - Giardina,F
AU  - Coffeng,LE
AU  - Farrell,SH
AU  - Vegvari,C
AU  - Werkman,M
AU  - Truscott,JE
AU  - Anderson,RM
AU  - de,Vlas SJ
DO  - 10.1371/journal.pntd.0007514
PY  - 2019///
SN  - 1935-2727
TI  - Sampling strategies for monitoring and evaluation of morbidity targets for soil-transmitted helminths
T2  - PLoS Neglected Tropical Diseases
UR  - http://dx.doi.org/10.1371/journal.pntd.0007514
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000473779100067&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/72092
VL  - 13
ER  -
Download