Association between allergic responses and Schistosoma mansoni infection in residents in a low-endemic setting in Brazil

• Published in: Revista da Sociedade Brasileira de Medicina Tropical
• Main Authors: Sara Menezes de Oliveira, Fernando Schemelzer de Moraes Bezerra, Teiliane Rodrigues Carneiro, Marta Cristhiany Cunha Pinheiro, José Ajax Nogueira Queiroz
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sociedade Brasileira de Medicina Tropical (SBMT) 2014
• Subjects: Schistosomiasis; Schistosoma mansoni; Allergy; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.1590/0037-8682-0249-2014; https://doaj.org/article/fe420bc57e174d32972025a6c32f4f59

Introduction Schistosomiasis is endemic in 76 countries and territories. Several studies have found an inverse correlation between parasitic disease and the development of allergies. The purpose of the present study was to determine whether infection with Schistosoma mansoni in subjects with a low parasite load is protective against allergy. The final sample consisted of 39 S. mansoni-positive and 52 S. mansoni-negative residents of a small community in northeastern Brazil. Methods All subjects were submitted to the Kato-Katz test, anti-S. mansoni IgG measurement, the prick test for aeroallergens, eosinophil counts and serum IgE measurement. Results Subjects who reacted to one or more antigens in the prick test were considered allergic. Only 7 S. mansoni-positive subjects (17.9%) reacted to one or more antigens, whereas 20 S. mansoni-negative subjects (38.5%) tested positive for allergy. Conclusions Our findings suggest that, in areas of low endemicity, infection with S. mansoni significantly reduces the risk of the development of allergy in subjects with a low parasite load.