Infection is as an important trigger for acute asthma and chronic obstructive pulmonary disease ( COPD). The aim of this article was to determine the prevalence and impact of virus and bacterial infections in acute asthma and COPD.
Subjects were recruited, within 24 h of hospital admission for acute exacerbations of asthma and COPD. Nose/throat swabs and sputum samples were collected and examined by multiplex polymerase chain reaction for respiratory viruses and cultured for bacteria. The primary outcomes were length of stay ( LOS) and readmission to hospital within 60 days.
A total of 199 subjects were recruited (96 had asthma and 103 COPD) for 235 events (36 re‐presented). A virus was detected in 79 subjects (40%), bacteria in 41 (21%), and of these, 18 had both. Rhinovirus A was the most frequently isolated virus. A multivariate analysis was performed to control for confounders. It found that detection of a virus, a virus and bacteria, forced expiratory volume in 1 s (FEV 1) and a diagnosis of COPD were all independent predictors of prolonged LOS, while risk of readmission within 60 days was increased with virus infection alone, virus and bacterial infection, lower FEV 1 and current smoking.
A virus infection with rhinovirus A has been demonstrated to be a likely trigger of acute asthma and COPD. Virus infection, in combination with a chronic bacterial infection, is an important determinant of more severe acute exacerbations and is more likely to result in hospital readmission following severe acute exacerbation.