Abstract
BACKGROUND: Acute respiratory infections are a major trigger of asthma exacerbations. This study sought to estimate the overall proportion of viruses, atypical pathogens, and bacteria detected in adults with asthma exacerbations. METHODS: PubMed, EMBASE, and Cochrane Library databases and all related studies from the reviews and references were searched from inception to February 13, 2020. Two authors independently performed study selection, data extraction, as well as quality evaluation. Subsequently, meta-analysis, between-study heterogeneity, and publication bias assessment were conducted on RStudio. RESULTS: Forty-three eligible studies comprising 3511 adults were included, of which 21 publications mentioned multiple infections during acute asthma attacks. Meta-analysis showed an acute infection prevalence of 40.19% (95% confidence interval [CI] 34.53%-45.99%). Viruses, atypical pathogens, and bacteria were detected in 38.76% (95% CI 32.02%-45.71%), 8.29% (95% CI 2.64%-16.27%), and 7.05% (95% CI 3.34%-11.81%) of asthmatics during exacerbations, respectively. Rhinovirus infections are always the dominant trigger for exacerbations with a proportion of 20.02% (95% CI 14.84%-25.73%). Substantial heterogeneity across studies (Cochran Q test: 479.43, P < 0.0001, I(2) = 91.2%) was explained by subgroup analysis, indicating that year, region, population, respiratory secretion, detection method, pathogen, and study quality were all influencing factors. CONCLUSION: This meta-analysis provided the first quantitative epidemiological data for adults, and in the future, more research and health-care supports are necessary in this area.