RSV present in 8.7% of outpatient COPD exacerbations, study finds
Of 310 chronic obstructive pulmonary disease (COPD) exacerbations at clinics in the United Kingdom and the Netherlands analyzed in a recent study, 27 were related to respiratory syncytial virus (RSV).
Respiratory syncytial virus (RSV) was found in 8.7% of outpatient-managed chronic obstructive pulmonary disease (COPD) exacerbations, a prospective cohort study showed.
Researchers recruited 377 patients with COPD from specialist clinics in the United Kingdom and the Netherlands between 2017 and 2019. Patients were observed for three consecutive RSV seasons, during exacerbations, and at least twice yearly. RSV infections were determined using reverse transcription-polymerase chain reaction (RT-PCR) and serologic testing. Median follow-up was 748 days in the U.K. cohort and 1,132 days in the Netherlands cohort. Findings were published by the American Journal of Respiratory and Critical Care Medicine on March 18.
Participants attended a total of 1,999 clinic visits and reported 310 COPD exacerbations. Of these exacerbations, 27 were related to RSV (8.7%). Seven RSV infections were determined only by PCR, 16 only by serology, and four by both methods. In addition, researchers found that increases in RSV-specific N-protein antibody were as sensitive as antibody to pre-F or post-F for serodiagnosis of RSV-related exacerbation. Researchers also found a greater variety of viruses in the U.K. sample and assessed these patients for exacerbation severity. They found no difference in exacerbation severity by RSV diagnostic methods and no correlation between viral load and exacerbation severity, but data showed RSV-related exacerbations tended to resolve more quickly.
The results confirm that many RSV infections in COPD patients would be missed if detection relied on PCR alone, as 59% of RSV-associated exacerbations were negative on PCR despite a swab being taken by highly trained staff within five days of symptom onset, the authors wrote.
Overall, "lower airway (sputum) sampling achieved a higher rate of RSV detection compared to upper airway (nasopharyngeal) swabs in COPD patients," they said.
Based on the findings, researchers also recommended patients with COPD "should be considered a priority for future studies of the effect of vaccination on exacerbation and lung function decline." Because 15 patients died during the study period and 14 required hospitalization, RSV infections associated with these events may have been missed, the authors cautioned.