In 2009, H1N1 influenza resulted in 87 000 hospitalizations among children. The most common comorbidity for patients hospitalized as a result of H1N1 infection was asthma. Were children with asthma more likely to be infected with H1N1 influenza?
A total of 161 children aged 4 to 12 years, 95 with asthma and 66 without asthma, were recruited from within a study of 193 children being studied for the effects of rhinovirus infection on asthma.
The children provided 8 weekly nasal mucus samples that were analyzed for respiratory viruses by polymerase chain reaction. Upper respiratory infection and asthma symptoms, morning peak expiratory flow rates, and albuterol use were recorded on daily diary cards. Loss of asthma control was defined as at least moderate asthma symptoms and either a decrease in peak expiratory flow of ≥20% or use of albuterol for ≥2 days per week.
Three hundred forty-six infections were detected: rhinoviruses...