Lack of Consistent Association between Asthma, Allergic Diseases, and Intestinal Helminth Infection in School-Aged Children in the Province of Bengo, Angola

Abstract

Epidemiological studies have shown conflicting findings on the relationship between asthma, atopy, and intestinal helminth infections. There are no such studies from Angola; therefore, we aimed to evaluate the relationship between asthma, allergic diseases, atopy, and intestinal helminth infection in Angolan schoolchildren. We performed a cross-sectional study of schoolchildren between September and November 2017. Five schools (three urban, two rural) were randomly selected. Asthma, rhinoconjunctivitis, and eczema were defined by appropriate symptoms in the previous 12 months: atopy was defined by positive skin prick tests (SPT) or aeroallergen-specific IgE; intestinal helminths were detected by faecal sample microscopy. In total, 1023 children were evaluated (48.4% female; 57.6% aged 10–14 years; 60.5% urban). Asthma, rhinoconjunctivitis, or eczema were present in 9%, 6%, and 16% of the studies children, respectively. Only 8% of children had positive SPT, but 64% had positive sIgE. Additionally, 40% were infected with any intestinal helminth (A. lumbricoides 25.9%, T. trichiura 7.6%, and H. nana 6.3%). There were no consistent associations between intestinal helminth infections and asthma, allergic diseases, or atopy, except for A. lumbricoides, which was inversely associated with rhinoconjuctivitis and directly associated with aeroallergen-specific IgE. We concluded that, overall, intestinal helminth infections were not consistently associated with allergic symptoms or atopy. Future, preferably longitudinal, studies should collect more detailed information on helminth infections as part of clusters of environmental determinants of allergies.

Association between Outdoor and Indoor Air Pollution Sources and Atopic Eczema among Preschool Children in South Africa

“…There was no significant association between EE and current ESs and the participants’ sex ( p > 0.005). Our findings were consistent with the ISAAC cross-sectional study, which included children aged 6 to 7 years in Angola and reported no association between sex and AE symptoms [ 57 ]. It is uncertain whether gender or sex makes young children more susceptible to eczema symptoms.…”

“…In this study, the overall prevalence of EE (11.9%) and current ESs (13.37%) was found to be lower than in other studies conducted in Africa, such as Angola, where EE was reported at 18.4% among 6-to 7-year-old children (Ref. [57]) and Ethiopia, where AE was reported at 21% among children under 12 years old [58]. It is worth noting that South Africa has a larger economy than Angola and Ethiopia [59], with the highest consumption of coal on the African continent in 2023.…”

Intestinal parasitic infections and predisposing factors among prison inmates in Southern Ghana: A cross‐sectional study

“…It is important to note that unrelated factors such as allergic reactions, dermatitis, and insect bites among others can contribute to skin itching. A study by Arrais et al 29 among Angolan school‐aged children has found no significant association between skin infection and intestinal helminthic infections.…”