Owada, KeiLau, ColleenLeonardo, Lydia RClements, ArchieYakob, LaithNielsen, MarkCarabin, HeleneSoares Magalhaes, Ricardo2020-12-162020-12-161756-3305http://hdl.handle.net/1885/217318Background Soil-transmitted helminth (STH) infections are highly prevalent in the Philippines. Mapping the prevalence and high-intensity of STH co-infections can help guide targeted intervention programmes to reduce morbidity, especially among vulnerable school-aged children. In this study, we aimed to predict the spatial distribution of the prevalence of Ascaris lumbricoides and Trichuris trichiura co-infection and infection intensity classes in the Philippines to identify populations most in need of interventions. Methods Data on STH infections from 29,919 individuals during the nationwide parasitological survey in 2005 to 2007 were included in the analysis. To geographically predict the prevalence of A. lumbricoides and T. trichiura co-infections and infection intensity classes, Bayesian multinomial geostatistical models were built including age, sex, environmental variables and a geostatistical random effect. The number of individuals co-infected and belonging to each of the infection intensity classes in 2017 was forecast by combining our predictive prevalence maps with population density maps. Results Our models showed that school-aged children (5–19 years) are most at risk of A. lumbricoides and T. trichiura co-infections and of moderate/high infection intensity compared to other age groups. We identified target provinces where the likelihood of STH-associated morbidity was highest: Luzon (Bulacan, Benguet, Cavite, Sorsogon, Metropolitan Manila, Pampanga and Rizal), the Visayas (Cebu, Iloilo, Leyte and Negros Occidental), and in Mindanao (Agusan Del Norte, Davao Del Sur, Davao Oriental, Lanao Del Sur, Maguindanao, Misamis Oriental, Sulu and Zamboanga Del Sur). Luzon had the highest estimated number of school-aged children with A. lumbricoides and T. trichiura co-infections (estimated total 89,400), followed by the Visayas (38,300) and Mindanao (20,200). Conclusions Our study provided epidemiological evidence to highlight national priority areas for controlling co-infections and high intensity infections in the Philippines. Our maps could assist more geographically targeted interventions to reduce the risk of STH-associated morbidity in the Philippines.KO is a PhD candidate supported by an Australian Government Research Training Programme Scholarship from the University of Queensland;MN isfunded by an Australian Research Council Discovery Project Grant (DP140101410); CLL is funded by an Australian National Health and Medical Research Council (NHMRC) Early Career Fellowship (1109035); ACAC is supported by a NHMRC Senior Research Fellowship; LY is funded by the Medical Research Council UK, the Newton Fund, the Wellcome Trust and the European Union.application/pdfen-AU© The Author(s). 2018https://creativecommons.org/licenses/by/4.0/Soil-transmitted helminthsAscaris lumbricoidesTrichuris trichiuraCo-infectionInfection intensitySpatial epidemiologyBayesian geostatisticsThe PhilippinesSpatial distribution and populations at risk of A. lumbricoides and T. trichiura co-infections and infection intensity classes: an ecological study201810.1186/s13071-018-3107-y2020-07-26e Creative Commons Attribution 4.0 International License