BACKGROUND: It has recently been argued that asthma does not increase the risk of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. If so, the prevalence of asthma in subjects diagnosed with COVID-19 should be lower than in the general population. OBJECTIVE: To determine the prevalence of asthma in Mexican children and adults with SARS-CoV-2 infection. METHODS: A public database of the Epidemiological Surveillance System for Viral Respiratory Disease in Mexico was analyzed. Those who underwent the real-time reverse transcriptase-polymerase chain reaction-SARS-CoV-2 (rtRT-PCR-SARS-CoV-2) test from February 27 to June 21, 2020, were included. In addition to the prevalence of asthma, some factors associated with it were investigated. RESULTS: Data from 417,366 subjects were analyzed. Asthma prevalence in children, adults, and global were 3.7%, 3.3%, and 3.3%, respectively. Although the asthma prevalence was lower in SARS-CoV-2 positive over negative patients, significant differences were only found in adults (2.8% vs. 3.7% respectively; odds ratio (OR) = 0.74; 95% confidence interval (CI): 0.71-0.77); but not in children (3.5% vs. 3.8%, respectively; OR = 0.91; 95%CI: 0.76-1.10). Multivariate analysis showed in younger than 18 years that girls and immunosuppression were factors associated with a decrease in the odds to develop asthma. In adults, asthma was positively associated with females, obesity, smoking, immunosuppression, chronic obstructive pulmonary disease, arterial hypertension, and cardiovascular disease. CONCLUSION: The prevalence of asthma in child and adult were lower than those previously reported. Our study seems to support the hypothesis that asthma patients have a lower risk of SARS-CoV-2 infection. Further studies are required to demonstrate the consistency of our findings.
Low prevalence of asthma in Mexican children and adults with a positive rtRT-PCR test for SARS-CoV-2: a cross-sectional study during the 2020 pandemic