Taken together this is the first controlled study on the relevance of hMPV in hospitalized AE-COPD. HMPV was detected in a very low frequency but with noticeable viral load in AE-COPD patients. Given that asymptomatic carriage of hMPV is very unlikely it should be considered as another possible trigger of AE-COPD. Since every AE-COPD has considerable impact on the course of the disease and regional outbreaks of hMPV are possible it should be included into future diagnostic and therapeutic considerations. 