title: Ascaris lumbricoids Infection as a Risk Factor for Asthma and Atopy in Rural Bangladeshi Children.
abstract: Controversy persists as to whether helminth infections cause or protect against asthma and atopy. The aim of this study was to investigate the effects of helminth infection on asthma and atopy among Bangladeshi children. A total of 912 children aged 4.5 years (mean = 54.4, range = 53.5-60.8 months) participated in a cross-sectional study nested into a randomized controlled trial in Bangladesh. Ever-asthma, ever-wheezing and current wheezing were identified using the International Study of Asthma and Allergies in Childhood questionnaire. Current helminth infection was defined by the presence of helminth eggs in stools, measured by routine microscopic examination. Repeated Ascaris infection was defined by the presence of anti-Ascaris IgE ≥ 0.70 UA/ml in serum measured by the CAP-FEIA method. Atopy was defined by specific IgE to house dust mite (anti-DP IgE) ≥ 0.70 UA/ml measured by the CAP-FEIA method and/or positive skin prick test (≥ 5 mm). Anti-Ascaris IgE was significantly associated with ever asthma (odds ratio (OR) = 1.86, 95% CI: 1.14-3.04, highest vs. lowest quartile; P for trend 0.016). Anti-Ascaris IgE was also significantly associated with positive anti-DP IgE (OR = 9.89, 95% CI: 6.52-15.00, highest vs. lowest; P for trend < 0.001) and positive skin prick test (OR = 1.69, 95% CI: 1.01-2.81, highest vs. lowest, P for trend 0.076). These findings suggest that repeated Ascaris infection is a risk factor for asthma and atopy in rural Bangladeshi children. Further analysis is required to examine the mechanism of developing asthma and atopy in relation to helminth infection.
authors.affiliation: Department of Clinical Trial and Clinical Epidemiology, Faculty of Medicine, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan ; International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b) , Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Mohammad D H
authors.initials: MD
authors.lastname: Hawlader
authors.affiliation: Department of Clinical Trial and Clinical Epidemiology, Faculty of Medicine, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Enbo
authors.initials: E
authors.lastname: Ma
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan ; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST) , 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Noguchi
authors.affiliation: Department of Infection and Immunology, Aichi Medical University School of Medicine , Nagakute, Aichi 480-1195, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Itoh
authors.affiliation: International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b) , Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Shams E
authors.initials: SE
authors.lastname: Arifeen
authors.affiliation: International Maternal and Child Health, Department of Women's and Children's Health, Uppsala University , SE-75185 Uppsala, Sweden.
authors.forename: Lars Å
authors.initials: LÅ
authors.lastname: Persson
authors.affiliation: MRC International Nutrition Group, Nutrition and Public Health Intervention Research Unit, Department of Epidemiology & Population Health, London School of Hygiene and Tropical Medicine , Keppel Street, London, WC1E 7HT, United Kingdom.
authors.forename: Sophie E
authors.initials: SE
authors.lastname: Moore
authors.affiliation: International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b) , Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Rubhana
authors.initials: R
authors.lastname: Raqib
authors.affiliation: Department of Clinical Trial and Clinical Epidemiology, Faculty of Medicine, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Wagatsuma
keywords: Bangladesh; IgE; atopy; helminth infection; pediatric asthma