title: Household and personal factors are sources of heterogenity in intestinal parasite clearance among Mexican children 6-15 months of age supplemented with vitamin A and zinc.
abstract: A randomised, double-blind, placebo-controlled trial was carried out among Mexico children aged 6-15 months to determine how household characteristics modify vitamin A and zinc supplementation efficacy on Ascaris lumbricoides, Giardia intestinalis and Entamoeba histolytica/E. dispar infection durations. Children assigned to receive vitamin A every 2 months, a daily zinc supplement, a combined vitamin A-zinc supplement or a placebo were followed for 1 year. Parametric hazard models were fit to infection durations stratified by personal and household factors. Children supplemented with vitamin A and zinc combined from households lacking piped water and children in all three treatment arms from households with dirt floors had longer G. intestinalis and A. lumbricoides infection durations than their counterparts, respectively. Shorter E. histolytica/E.dispar durations were found among zinc-supplemented children of mothers who had <6 years of education and no indoor bathrooms. Heterogeneity in supplementation efficacy among children may reflect differences in exposure risk and baseline immune responses.
authors.affiliation: Government Primary Health Center, Madurai, India.
authors.forename: Punitha
authors.initials: P
authors.lastname: Srinivasan
authors.affiliation: UN World Food Programme, West Timor, Indonesia.
authors.forename: Ha'i Raga
authors.initials: HR
authors.lastname: Lawa
authors.affiliation: School of Natural Sciences, Universidad Autónoma de Querétaro, Querétaro, Mexico.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Rosado
authors.affiliation: University of Queensland School of Population Health, Herston, Qld, Australia.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Al Mamun
authors.affiliation: QIMR Berghofer Medical Research Institute, Herston, Australia.
authors.forename: Mohsina
authors.initials: M
authors.lastname: Khatun
authors.affiliation: School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.
authors.forename: José I
authors.initials: JI
authors.lastname: Santos
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Jürg
authors.initials: J
authors.lastname: Utzinger
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland. Electronic address: kurt.long@unibas.ch.
authors.forename: Kurt Z
authors.initials: KZ
authors.lastname: Long
mesh_terms: D000818:Animals; D001196:Ascariasis / Q000188:drug therapy; D017164:Ascaris lumbricoides / Q000472:pathogenicity; D019587:Dietary Supplements; D004311:Double-Blind Method; D005191:Family Characteristics; D005243:Feces / Q000469:parasitology; D005260:Female; D016829:Giardia lamblia / Q000472:pathogenicity; D005873:Giardiasis / Q000188:drug therapy; D006798:Housing / Q000592:standards; D006801:Humans; D007223:Infant; D007411:Intestinal Diseases, Parasitic / Q000188:drug therapy*; D008297:Male; D008800:Mexico; D010270:Parasite Egg Count; D010290:Parents / Q000193:education; D011446:Prospective Studies; D014801:Vitamin A / Q000008:administration & dosage*; D014815:Vitamins / Q000008:administration & dosage*; D015032:Zinc / Q000008:administration & dosage*
chemical_list: D014815:Vitamins; D014801:Vitamin A; D015032:Zinc
keywords: Ascaris lumbricoides; Entamoeba histolytica/E. dispar; Giardia intestinalis; Vitamin A; zinc