title: Geographical distribution of human Schistosoma japonicum infection in The Philippines: tools to support disease control and further elimination.
abstract: Schistosoma japonicum infection is believed to be endemic in 28 of the 80 provinces of The Philippines and the most recent data on schistosomiasis prevalence have shown considerable variability between provinces. In order to increase the efficient allocation of parasitic disease control resources in the country, we aimed to describe the small-scale spatial variation in S. japonicum prevalence across The Philippines, quantify the role of the physical environment in driving the spatial variation of S. japonicum, and develop a predictive risk map of S. japonicum infection. Data on S. japonicum infection from 35,754 individuals across the country were geo-located at the barangay level and included in the analysis. The analysis was then stratified geographically for the regions of Luzon, the Visayas and Mindanao. Zero-inflated binomial Bayesian geostatistical models of S. japonicum prevalence were developed and diagnostic uncertainty was incorporated. Results of the analysis show that in the three regions, males and individuals aged ⩾20years had significantly higher prevalence of S. japonicum compared with females and children <5years. The role of the environmental variables differed between regions of The Philippines. Schistosoma japonicum infection was widespread in the Visayas whereas it was much more focal in Luzon and Mindanao. This analysis revealed significant spatial variation in the prevalence of S. japonicum infection in The Philippines. This suggests that a spatially targeted approach to schistosomiasis interventions, including mass drug administration, is warranted. When financially possible, additional schistosomiasis surveys should be prioritised for areas identified to be at high risk but which were under-represented in our dataset.
authors.affiliation: University of Queensland, Infectious Disease Epidemiology Unit, School of Population Health, Public Health Building, Herston Road, 4006 Herston, Australia; University of Queensland, School of Veterinary Science, Gatton, 4343 Gatton, Australia. Electronic address: r.magalhaes@uq.edu.au.
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Soares Magalhães
authors.affiliation: University of The Philippines-Manila, College of Public Health, Department of Parasitology, Ermita, Manila, Philippines.
authors.forename: Maria Sonia
authors.initials: MS
authors.lastname: Salamat
authors.affiliation: University of The Philippines-Manila, College of Public Health, Department of Parasitology, Ermita, Manila, Philippines.
authors.forename: Lydia
authors.initials: L
authors.lastname: Leonardo
authors.affiliation: University of Queensland, Infectious Disease Epidemiology Unit, School of Population Health, Public Health Building, Herston Road, 4006 Herston, Australia; Infectious Disease Division, Queensland Institute of Medical Research, Herston, Queensland, Australia; Research School of Population Health, The Australian National University, Canberra, Australia.
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Gray
authors.affiliation: Department of Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, OK, USA.
authors.forename: Hélène
authors.initials: H
authors.lastname: Carabin
authors.affiliation: Institute for Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia.
authors.forename: Kate
authors.initials: K
authors.lastname: Halton
authors.affiliation: Infectious Disease Division, Queensland Institute of Medical Research, Herston, Queensland, Australia.
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
authors.affiliation: University of Queensland, Infectious Disease Epidemiology Unit, School of Population Health, Public Health Building, Herston Road, 4006 Herston, Australia.
authors.forename: Gail M
authors.initials: GM
authors.lastname: Williams
authors.affiliation: University of The Philippines-Manila, College of Public Health, Department of Parasitology, Ermita, Manila, Philippines.
authors.forename: Pilarita
authors.initials: P
authors.lastname: Rivera
authors.affiliation: University of The Philippines-Manila, College of Public Health, Department of Parasitology, Ermita, Manila, Philippines.
authors.forename: Ofelia
authors.initials: O
authors.lastname: Saniel
authors.affiliation: Philippine Department of Health National Center for Disease Prevention and Control, Manila, Philippines.
authors.forename: Leda
authors.initials: L
authors.lastname: Hernandez
authors.affiliation: University of Queensland, Infectious Disease Epidemiology Unit, School of Population Health, Public Health Building, Herston Road, 4006 Herston, Australia.
authors.forename: Laith
authors.initials: L
authors.lastname: Yakob
authors.affiliation: International Health Institute, Brown University, Providence, RI, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: McGarvey
authors.affiliation: University of Queensland, Infectious Disease Epidemiology Unit, School of Population Health, Public Health Building, Herston Road, 4006 Herston, Australia; Research School of Population Health, The Australian National University, Canberra, Australia.
authors.forename: Archie
authors.initials: A
authors.lastname: Clements
mesh_terms: D000293:Adolescent; D000818:Animals; D001499:Bayes Theorem; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D005243:Feces / Q000469:parasitology; D005260:Female; D062306:Geography, Medical; D006801:Humans; D008297:Male; D015233:Models, Statistical; D010270:Parasite Egg Count; D010679:Philippines / Q000453:epidemiology; D015995:Prevalence; D012550:Schistosoma mansoni / Q000302:isolation & purification; D012554:Schistosomiasis japonica / Q000453:epidemiology* / Q000517:prevention & control; D055815:Young Adult
keywords: Disease control; Disease elimination; Philippines; Risk mapping; Schistosoma japonicum