Independent effects of intestinal parasite infection and domestic allergen exposure on risk of wheeze in Ethiopia: A nested case-control study

Sarah Scrivener, Haile Yemaneberhan, Mehila Zebenigus, Daniel Tilahun, Samuel Girma, Seid Ali, Paul McElroy, Adnan Custovic, Ashley Woodcock, David Pritchard, Andrea Venn, John Britton

    Research output: Contribution to journalArticlepeer-review


    Background: Why asthma is rare in rural subsistence societies is not clear. We tested the hypotheses that the risk of asthma is reduced by intestinal parasites or hepatitis A infection, and increased by exposure to dust-mite allergen or organophosphorus insecticides in urban and rural areas of Jimma, Ethiopia. Methods: From 12 876 individuals who took part in a study of asthma and atopy in urban and rural Jimma in 1996, we identified all who reported wheeze in the previous 12 months, and a random subsample of controls. In 1999, we assessed parasites in faecal samples, Der p 1 levels in bedding, hepatitis A antibodies, serum cholinesterase (a marker of organophosphorus exposure), total and specific serum IgE, and skin sensitisation to Dermatophagoides pteronyssinus in 205 cases and 399 controls aged over 16 years. The effects of parasitosis, Der p 1 level, hepatitis A seropositivity, and cholinesterase concentration on risk of wheeze, and the role of IgE and skin sensitisation in these associations, were analysed by multiple logistic regression. Findings: The risk of wheeze was independently reduced by hookworm infection by an odds ratio of 0.48 (95% CI 0.24-0.93, p=0.03), increased in relation to Der p 1 level (odds ratio per quartile 1.26 [1.00-1.59], p=0.05), and was unrelated to hepatitis A seropositivity or cholinesterase concentration. In the urban population, D pteronyssinus skin sensitisation was more strongly related to wheeze (9.45 [5.03-17.75]) than in the rural areas (1.95 [0.58-6.61], p for interaction=0.017), where D pteronyssinus sensitisation was common, but unrelated to wheeze in the presence of high-intensity parasite infection. Interpretation: High degrees of parasite infection might prevent asthma symptoms in atopic individuals.
    Original languageEnglish
    Pages (from-to)1493-1499
    Number of pages6
    JournalThe Lancet
    Issue number9292
    Publication statusPublished - 3 Nov 2001


    • Adolescent
    • Adult
    • Antigens, Dermatophagoides
    • epidemiology: Asthma
    • Case-Control Studies
    • Comparative Study
    • Cross-Sectional Studies
    • epidemiology: Ethiopia
    • parasitology: Feces
    • Female
    • immunology: Glycoproteins
    • Humans
    • parasitology: Intestinal Diseases
    • Logistic Models
    • Male
    • Middle Aged
    • Research Support, Non-U.S. Gov't
    • Respiratory Sounds
    • Risk Factors
    • Rural Population
    • Urban Population


    Dive into the research topics of 'Independent effects of intestinal parasite infection and domestic allergen exposure on risk of wheeze in Ethiopia: A nested case-control study'. Together they form a unique fingerprint.

    Cite this