Poor sanitation and helminth infection protect against skin sensitization in Vietnamese children: A cross-sectional study

TY - JOUR

T1 - Poor sanitation and helminth infection protect against skin sensitization in Vietnamese children

T2 - A cross-sectional study

AU - Flohr, Carsten

AU - Tuyen, Luc Nguyen

AU - Lewis, Sarah

AU - Quinnell, Rupert

AU - Minh, Truong Tan

AU - Liem, Ho Thanh

AU - Campbell, Jim

AU - Pritchard, David

AU - Hien, Tran Tinh

AU - Farrar, Jeremy

AU - Williams, Hywel

AU - Britton, John

N1 - Funding Information: C. Flohr is supported by a Radcliffe Research Fellowship from University College, University of Oxford, United Kingdom, a research grant from Asthma UK, and the Bastow Award from the Special Trustees for Nottingham University Hospitals.

PY - 2006/12

Y1 - 2006/12

N2 - Background: Geohelminth infection and poor hygiene may be protective against allergic sensitization. Objective: To determine whether current helminth infection is associated with a reduced prevalence of allergen skin test sensitization in a Southeast Asian population of children with a high prevalence of hookworm infection. Methods: A total of 1742 Vietnamese schoolchildren were invited to take part in a cross-sectional survey. Allergen skin sensitization to house dust mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae) and American cockroach (Periplaneta americana) were measured and stool samples for qualitative and quantitative geohelminth estimation collected. Results: A total of 1601 children age 6 to 18 participated. Sensitization to dust mites was present in 14.4% and to cockroach in 27.6% of children. In a mutually adjusted model, the risk of sensitization to dust mites was reduced in those with higher hookworm burden (adjusted odds ratio [OR] for 350+ vs no eggs per gram, 0.61; 95% CI, 0.39-0.96) and with Ascaris infection (adjusted OR, 0.28; 0.10-0.78), and increased in those using flush toilets (adjusted OR for flush toilet vs none/bush/pit, 2.51; 1.00-6.28). In contrast, sensitization to cockroach was not independently related to geohelminth infection but was increased in those regularly drinking piped or well water rather than from a stream (adjusted OR, 1.33; 1.02-1.75). Conclusion: Geohelminth infection, sanitation, and water supply influence the risk of allergic sensitization in Vietnamese children. This is consistent with a protective effect against allergy by geohelminth or other gastrointestinal infection. Clinical implications: If the inverse relationship between geohelminth infection, poor sanitation, and allergic sensitization proves to be causal, drugs derived from parasite products may help to alleviate clinical allergic disease.

AB - Background: Geohelminth infection and poor hygiene may be protective against allergic sensitization. Objective: To determine whether current helminth infection is associated with a reduced prevalence of allergen skin test sensitization in a Southeast Asian population of children with a high prevalence of hookworm infection. Methods: A total of 1742 Vietnamese schoolchildren were invited to take part in a cross-sectional survey. Allergen skin sensitization to house dust mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae) and American cockroach (Periplaneta americana) were measured and stool samples for qualitative and quantitative geohelminth estimation collected. Results: A total of 1601 children age 6 to 18 participated. Sensitization to dust mites was present in 14.4% and to cockroach in 27.6% of children. In a mutually adjusted model, the risk of sensitization to dust mites was reduced in those with higher hookworm burden (adjusted odds ratio [OR] for 350+ vs no eggs per gram, 0.61; 95% CI, 0.39-0.96) and with Ascaris infection (adjusted OR, 0.28; 0.10-0.78), and increased in those using flush toilets (adjusted OR for flush toilet vs none/bush/pit, 2.51; 1.00-6.28). In contrast, sensitization to cockroach was not independently related to geohelminth infection but was increased in those regularly drinking piped or well water rather than from a stream (adjusted OR, 1.33; 1.02-1.75). Conclusion: Geohelminth infection, sanitation, and water supply influence the risk of allergic sensitization in Vietnamese children. This is consistent with a protective effect against allergy by geohelminth or other gastrointestinal infection. Clinical implications: If the inverse relationship between geohelminth infection, poor sanitation, and allergic sensitization proves to be causal, drugs derived from parasite products may help to alleviate clinical allergic disease.

KW - Atopy

KW - epidemiology

KW - helminths

KW - hygiene hypothesis

UR - http://www.scopus.com/inward/record.url?scp=33845364518&partnerID=8YFLogxK

U2 - 10.1016/j.jaci.2006.08.035

DO - 10.1016/j.jaci.2006.08.035

M3 - Article

C2 - 17157661

AN - SCOPUS:33845364518

SN - 0091-6749

VL - 118

SP - 1305

EP - 1311

JO - Journal of Allergy and Clinical Immunology

JF - Journal of Allergy and Clinical Immunology

IS - 6

ER -