Human metapneumovirus and community-acquired pneumonia in children

Background: Human metapneumovirus (hMPV) was first recognized in the Netherlands in 2001 from nasopharyngeal aspirate samples and was associated with respiratory tract illness in the pediatric population. This was the first report of metapneumovirus infections in community-acquired pneumonia in Taiwan. Methods: A total of 116 nasopharyngeal aspirate samples from patients with community-acquired pneumonia was examined by reverse transcriptase polymerase chain reaction (RT-PCR). Other respiratory tract pathogens were also examined. The clinical characteristics and laboratory data were analyzed. Results: Out of the 116 patients, potential causative agents were detected in 95 (81.9%) patients. A total of six human metapneumovirus RT-PCR positive samples was identified. All of these had evidence of coinfection with bacteria (3 Streptococcus pneumoniae, 2 Mycoplasma pneumoniae, 1 Chlamydia pneumoniae). Coinfection with other respiratory viruses was also observed in two cases (1 influenza A, 1 parainfluenza type 3). The age distribution was seven to 11 years except for one patient who was two years of age (Case 1). The most common clinical findings were fever (6/6, 100%), cough (6/6,100%), rhinorrhea (5/6, 83.3%), rales (5/6, 83.3%) and wheezing (1/6, 16.7%). Chest radiographs revealed four with lobar patches and two with interstitial infiltrations. The mean duration of hospital stay was 5.5 ± 2.8 days. All patients made a complete recovery. Conclusions: hMPV was identified in 5.2% of patients with community-acquired pneumonia. Our data showed a high rate of coinfection with hMPV in community-acquired pneumonia. Human metapneumovirus infection, like other respiratory viruses, may predispose to secondary bacterial pneumonia.