TY - JOUR
T1 - Longitudinal monitoring of prevalence and intensity of soil-transmitted helminth infections as part of community-wide mass drug administration within the Geshiyaro project in the Bolosso Sore district, Wolaita, Ethiopia
AU - Landeryou, Toby
AU - Maddren, Rosie
AU - Rayment Gomez, Santiago
AU - Kalahasti, Suprabhath
AU - Liyew, Ewnetu Firdawek
AU - Chernet, Melkie
AU - Mohammed, Hussein
AU - Wuletaw, Yonas
AU - Truscott, James
AU - Phillips, Anna E
AU - Ower, Alison
AU - Forbes, Kathryn
AU - Anjulo, Ufaysa
AU - Mengistu, Birhan
AU - Tasew, Geremew
AU - Salasibew, Mihretab
AU - Anderson, Roy
PY - 2022/9/19
Y1 - 2022/9/19
N2 - Mass drug administration (MDA), targeted at school-aged children (SAC) is recommended by the World Health Organization for the control of morbidity induced by soil-transmitted helminth (STH) infection in endemic countries. However, MDA does not prevent reinfection between treatment rounds, and research suggests that only treating SAC will not be sufficient to interrupt transmission of STH. In countries with endemic infection, such as Ethiopia, the coverage, community-groups targeted, and rates of reinfection will determine how effective MDA is in suppressing transmission in the long-term. In this paper, individually-linked longitudinal data from three epidemiological STH surveys conducted between November 2018 and November 2020 in the Wolaita region of Ethiopia are analysed to determine how STH prevalence and intensity changes according to individual level treatment data collected over two rounds of MDA. This study demonstrates that while community-wide MDA successfully reduces overall infection intensity across the villages treated, the observed levels of non-compliance to treatment by individuals acts to maintain levels of parasite abundance whereby transmission interruption is not possible at to, despite reasonable levels of MDA coverage in the communities studied (ranging from 65% to 84% of the village populations). This quantifies with substantial data the often-postulated difference between coverage (accepting treatment) and compliance (swallowing of treatment), the latter impacting the former to a previously unquantified level. The paper highlights the need to focus treatment to partially treated, or never treated groups of individuals within existing community wide MDA control activities to interrupt the transmission of STH, and to reduce the basic reproductive number, R0, of the parasites to less than unity in value.
AB - Mass drug administration (MDA), targeted at school-aged children (SAC) is recommended by the World Health Organization for the control of morbidity induced by soil-transmitted helminth (STH) infection in endemic countries. However, MDA does not prevent reinfection between treatment rounds, and research suggests that only treating SAC will not be sufficient to interrupt transmission of STH. In countries with endemic infection, such as Ethiopia, the coverage, community-groups targeted, and rates of reinfection will determine how effective MDA is in suppressing transmission in the long-term. In this paper, individually-linked longitudinal data from three epidemiological STH surveys conducted between November 2018 and November 2020 in the Wolaita region of Ethiopia are analysed to determine how STH prevalence and intensity changes according to individual level treatment data collected over two rounds of MDA. This study demonstrates that while community-wide MDA successfully reduces overall infection intensity across the villages treated, the observed levels of non-compliance to treatment by individuals acts to maintain levels of parasite abundance whereby transmission interruption is not possible at to, despite reasonable levels of MDA coverage in the communities studied (ranging from 65% to 84% of the village populations). This quantifies with substantial data the often-postulated difference between coverage (accepting treatment) and compliance (swallowing of treatment), the latter impacting the former to a previously unquantified level. The paper highlights the need to focus treatment to partially treated, or never treated groups of individuals within existing community wide MDA control activities to interrupt the transmission of STH, and to reduce the basic reproductive number, R0, of the parasites to less than unity in value.
KW - Animals
KW - Anthelmintics/therapeutic use
KW - Child
KW - Ethiopia/epidemiology
KW - Helminthiasis/drug therapy
KW - Helminths
KW - Humans
KW - Mass Drug Administration
KW - Prevalence
KW - Reinfection
KW - Soil/parasitology
UR - http://www.scopus.com/inward/record.url?scp=85139377461&partnerID=8YFLogxK
U2 - 10.1371/journal.pntd.0010408
DO - 10.1371/journal.pntd.0010408
M3 - Article
C2 - 36121895
SN - 1935-2727
VL - 16
JO - PLoS Neglected Tropical Diseases
JF - PLoS Neglected Tropical Diseases
IS - 9
M1 - e0010408
ER -