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Hay fever, asthma, and eczema and early infectious diseases among children in Kilimanjaro, Tanzania
Author(s) -
Wander Katherine,
ShellDuncan Bettina,
Brindle Eleanor,
O'Connor Kathleen
Publication year - 2017
Publication title -
american journal of human biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.559
H-Index - 81
eISSN - 1520-6300
pISSN - 1042-0533
DOI - 10.1002/ajhb.22957
Subject(s) - hay fever , medicine , tanzania , asthma , hygiene hypothesis , allergy , incidence (geometry) , pediatrics , hygiene , immunoglobulin e , disease , immunology , atopy , antibody , pathology , physics , environmental science , environmental planning , optics
Objectives To investigate the hygiene (or “old friends”) hypothesis in a high‐infectious disease (ID) environment, rural Kilimanjaro, Tanzania. Methods Among a cross‐sectional sample of 2‐ to 7‐year‐old children, we collected physician‐diagnosed hay fever, asthma, and eczema, history of hospitalization, family size, and household environment information via questionnaire; performed active and passive surveillance for ID; and, evaluated total immunoglobulin E (IgE) and biomarkers of inflammation in dried blood spot specimens. We used regression models to describe patterns in allergic diseases. Results Complete information was available for 280 children: 12.5% had been diagnosed with hay fever; 18.9% with eczema; 2.1% with asthma. There was a positive association between hay fever and eczema diagnoses (π 2 : 4.07; P = 0.044); total IgE was positively associated with eczema ( β : 0.24; P = 0.100) and allergic diseases together ( β : 0.26; P = 0.042). ID were common: the incidence of any ID diagnosis was 28 per 100 children per month. Hay fever was inversely associated with household animals (OR: 0.27; P = 0.006), and positively associated with earth housing materials (OR: 1.93; P = 0.079) and hospitalization in infancy with an ID (3.16; P = 0.066); patterns were similar when allergic disease outcomes were considered together. Few associations between these predictors and eczema or asthma alone were apparent. Conclusions Allergic diseases were common among children in Kilimanjaro. The inverse association between household animals and allergy is consistent with the hygiene/old friends hypothesis; however, positive associations between allergic diseases and earth housing materials and early hospitalization with ID bear further explanation.