Helminth infections and allergies in Ghana

Abstract

Recent studies indicate that there is a global rise in the prevalence of asthma and other allergic disorders. Several epidemiological studies conducted in countries endemic for parasitic worms (helminths) have reported an inverse association between the presence of helminth infections and allergic disease. The main objectives of the study described in this thesis were to: i. To determine urban-rural differences in allergy outcomes in Ghana, West Africa ii. To examine the association between helminth infections and allergies iii. To characterize IgE responses associated with helminth infections and allergies The thesis describes cross-sectional studies among schoolchildren aged 5-16 years living in urban and rural areas of Southern Ghana. Study findings showed marked urban-rural differences in the prevalence of allergy outcomes with current infection with the waterborne helminth schistosoma being inversely associated with mite skin prick test allergic sensitization. In the study population, elevated levels of allergen specific IgE were observed that did not translate into skin reactivity or reported symptoms. Differences in gene expression profiles were also observed between urban and rural children. Overall, study findings indicate that factors associated with urbanization such as reduced exposure to parasitic worms are associated with the increased prevalence of allergy outcomes in Ghanaian children