ABSTRACT
PURPOSE: Urbanization is associated with the risk of developing allergic conditions. Few studies have evaluated the urban-rural disparity of allergic diseases in sub-Saharan Africa. OBJECTIVE: To compare the epidemiology of adult asthma and allergies in urban and rural Nigeria. SUBJECTS AND METHODS: A population-based cross-sectional study was performed among 910 subjects in Kwara State, North Central Nigeria, comprising 635 urban and 275 rural adults who were randomly selected. We used standardized questionnaires for data collection. RESULTS: The age-adjusted prevalence of adults reporting a previous "asthma attack" or "currently taking asthma medication" within the preceding 12 months (ECRHS asthma definition) was 3.4% urban, 0.5% rural, current allergic rhinoconjunctivitis (26.2% urban, 22.2% rural), and current skin allergy (13.9% urban, 10.5% rural). The age-adjusted prevalence of "physician-diagnosed allergic conditions": asthma (3.3% urban, 1.5% rural), allergic rhinoconjunctivitis (4.9% urban, 3.2% rural), and skin allergy (4.8% urban, 4.6% rural) were higher in urban areas than in rural areas. Urban areas recorded a higher age-adjusted 12 months prevalence of wheezing, night waking by breathlessness, night waking by chest tightness, asthma attack (p=0.042), and current use of asthma medication (p=0.031) than the rural areas. In the urban areas, 81% of those with asthma significantly had current allergic rhinoconjunctivitis, and 40.5% had current skin allergy, whereas in the rural areas, all subjects with asthma had current allergic rhinoconjunctivitis and 12.5% had current skin allergy (p=0.482). The most common trigger for asthma attack/respiratory symptoms among the urban household was exposure to environmental smoke (17.2%), and among the rural household, it was dust exposure (18.2%). Living in urban areas significantly increased the odds of having asthma [aOR: 5.6 (95% CI:1.6-19.6)] and allergic rhinoconjunctivitis [aOR: 1.7 (95% CI: 1.2-2.4)]. CONCLUSION: This study shows that urban residents frequently reported more allergic and respiratory symptoms and were at risk of having asthma and allergic rhinitis compared to rural residents. The findings would assist the physicians in understanding the urban-rural differences in the occurrence of allergic conditions, symptom triggers, and comorbidity, which are relevant in patient's clinical evaluation, treatment, and disease prevention.
ABSTRACT
Background: Information about the burden of asthma during pregnancy in Africa is scarce.Objectives: To determine the prevalence of asthma and respiratory symptoms in pregnancy in Ilorin, Nigeria.Methods: This study uses the European Community Respiratory Health Survey (ECRHS) questionnaire and definitions to screen 870 pregnant women attending three hospitals for asthma.Results: The prevalence of possible asthma (i.e. awakened by shortness of breath, asthma attack(s) in the last 12 months, or currently taking asthma medication) was 2.1% (95% CI: 1.3-3.1%), physician-diagnosed asthma was 1.0% (95% CI: 0.5-1.7%), and current asthma (asthma attack in the last 12 months and currently taking asthma medication) was 0.7% (95% CI: 0.2-1.3%). The prevalence of respiratory symptoms ranged from 0.6% (95% CI: 0.1-1.1%) for wheezing without cold to 12.9% (95% CI: 10.7-15.2%) for nasal allergies. Less than 1% reported an asthma attack and using asthma medication in the last 12 months. None of the pregnant women smoked tobacco during pregnancy. Pregnant women with possible asthma experienced more respiratory symptoms and worsening symptoms than those without asthma (15.8% vs. 3.9%), and the most reported symptom was being awakened by shortness of breath. The majority (55.6%) with physician-diagnosed asthma had suffered an asthma attack in the current pregnancy with a median of two attacks.Conclusion: The prevalence of asthma and respiratory symptoms in pregnancy in this sample was low, but we observed an increase and worsening of respiratory symptoms during pregnancy in those with asthma. Hence, the priority of clinicians should be disease control to prevent feto-maternal morbidity and mortality.
