TY - JOUR
T1 - Transmission Assessment Surveys (TAS) to Define Endpoints for Lymphatic Filariasis Mass Drug Administration
T2 - A Multicenter Evaluation
AU - Chu, Brian K.
AU - Deming, Michael
AU - Biritwum, Nana Kwadwo
AU - Bougma, Windtaré R.
AU - Dorkenoo, Améyo M.
AU - El-Setouhy, Maged
AU - Fischer, Peter U.
AU - Gass, Katherine
AU - Gonzalez de Peña, Manuel
AU - Mercado-Hernandez, Leda
AU - Kyelem, Dominique
AU - Lammie, Patrick J.
AU - Flueckiger, Rebecca M.
AU - Mwingira, Upendo J.
AU - Noordin, Rahmah
AU - Offei Owusu, Irene
AU - Ottesen, Eric A.
AU - Pavluck, Alexandre
AU - Pilotte, Nils
AU - Rao, Ramakrishna U.
AU - Samarasekera, Dilhani
AU - Schmaedick, Mark A.
AU - Settinayake, Sunil
AU - Simonsen, Paul E.
AU - Supali, Taniawati
AU - Taleo, Fasihah
AU - Torres, Melissa
AU - Weil, Gary J.
AU - Won, Kimberly Y.
PY - 2013
Y1 - 2013
N2 - Background:Lymphatic filariasis (LF) is targeted for global elimination through treatment of entire at-risk populations with repeated annual mass drug administration (MDA). Essential for program success is defining and confirming the appropriate endpoint for MDA when transmission is presumed to have reached a level low enough that it cannot be sustained even in the absence of drug intervention. Guidelines advanced by WHO call for a transmission assessment survey (TAS) to determine if MDA can be stopped within an LF evaluation unit (EU) after at least five effective rounds of annual treatment. To test the value and practicality of these guidelines, a multicenter operational research trial was undertaken in 11 countries covering various geographic and epidemiological settings.Methodology:The TAS was conducted twice in each EU with TAS-1 and TAS-2 approximately 24 months apart. Lot quality assurance sampling (LQAS) formed the basis of the TAS survey design but specific EU characteristics defined the survey site (school or community), eligible population (6-7 year olds or 1st-2nd graders), survey type (systematic or cluster-sampling), target sample size, and critical cutoff (a statistically powered threshold below which transmission is expected to be no longer sustainable). The primary diagnostic tools were the immunochromatographic (ICT) test for W. bancrofti EUs and the BmR1 test (Brugia Rapid or PanLF) for Brugia spp. EUs.Principal Findings/Conclusions:In 10 of 11 EUs, the number of TAS-1 positive cases was below the critical cutoff, indicating that MDA could be stopped. The same results were found in the follow-up TAS-2, therefore, confirming the previous decision outcome. Sample sizes were highly sex and age-representative and closely matched the target value after factoring in estimates of non-participation. The TAS was determined to be a practical and effective evaluation tool for stopping MDA although its validity for longer-term post-MDA surveillance requires further investigation.
AB - Background:Lymphatic filariasis (LF) is targeted for global elimination through treatment of entire at-risk populations with repeated annual mass drug administration (MDA). Essential for program success is defining and confirming the appropriate endpoint for MDA when transmission is presumed to have reached a level low enough that it cannot be sustained even in the absence of drug intervention. Guidelines advanced by WHO call for a transmission assessment survey (TAS) to determine if MDA can be stopped within an LF evaluation unit (EU) after at least five effective rounds of annual treatment. To test the value and practicality of these guidelines, a multicenter operational research trial was undertaken in 11 countries covering various geographic and epidemiological settings.Methodology:The TAS was conducted twice in each EU with TAS-1 and TAS-2 approximately 24 months apart. Lot quality assurance sampling (LQAS) formed the basis of the TAS survey design but specific EU characteristics defined the survey site (school or community), eligible population (6-7 year olds or 1st-2nd graders), survey type (systematic or cluster-sampling), target sample size, and critical cutoff (a statistically powered threshold below which transmission is expected to be no longer sustainable). The primary diagnostic tools were the immunochromatographic (ICT) test for W. bancrofti EUs and the BmR1 test (Brugia Rapid or PanLF) for Brugia spp. EUs.Principal Findings/Conclusions:In 10 of 11 EUs, the number of TAS-1 positive cases was below the critical cutoff, indicating that MDA could be stopped. The same results were found in the follow-up TAS-2, therefore, confirming the previous decision outcome. Sample sizes were highly sex and age-representative and closely matched the target value after factoring in estimates of non-participation. The TAS was determined to be a practical and effective evaluation tool for stopping MDA although its validity for longer-term post-MDA surveillance requires further investigation.
UR - http://www.scopus.com/inward/record.url?scp=84892687383&partnerID=8YFLogxK
U2 - 10.1371/journal.pntd.0002584
DO - 10.1371/journal.pntd.0002584
M3 - Article
C2 - 24340120
AN - SCOPUS:84892687383
SN - 1935-2727
VL - 7
JO - PLoS Neglected Tropical Diseases
JF - PLoS Neglected Tropical Diseases
IS - 12
M1 - e2584
ER -