Pneumonia is an important cause of morbidity and hospitalization in children worldwide. Since the development of nucleic acid amplification techniques, rhinovirus (RV) is frequently detected in community-acquired pneumonia (CAP), but the causative role of RV in pneumonia is still questioned. Empyema is a severe complication of pneumonia, and the evaluation of its long-term consequences is necessary.

We studied the viral aetiology of childhood CAP by searching for 18 respiratory viruses and six bacteria in sputum specimens (n = 76). The clinical characteristics and prevalence of RV pneumonia and its risk factors were evaluated by retrospectively comparing the medical record data of RV-positive (n = 82) and RV-negative (n = 231) children hospitalized for CAP. We also prospectively investigated viral and bacterial biomarker levels in children hospitalized for CAP (n = 24), focusing on RV pneumonia. Finally, we investigated the long-term outcome of childhood parapneumonic empyema (n = 26) at 3–19 years’ follow-up by a detailed interview, physical examination, lung imaging and lung function tests.

Viruses were detected in 72%, bacteria in 91%, and both in 66% of children hospitalized for CAP. RV, human bocavirus, and human metapneumovirus were the most commonly found viruses. Treatment failures were documented in viral-bacterial co-infections. Young age and a history of preterm birth were associated with RV-positive pneumonia, but the clinical features of pneumonia were similar in RV-positive and RV-negative children. RV-positive children had elevated levels of bacterial biomarkers, but a viral biomarker myxovirus resistance protein A remained low. Lung magnetic resonance imaging showed abnormal findings in 92% and significant pleural scarring in 25% of the children recovered from empyema, but most patients had normal lung function, chest radiograph and clinical recovery.

Viral-bacterial co-detections are common in childhood CAP and potentially associated with treatment failure. RV is commonly detected in young children with pneumonia and it is often associated with bacterial co-infection. Making the decision to withdraw antibiotics in children with pneumonia is challenging. Further studies and strategies are needed to differentiate viral from bacterial or mixed viral-bacterial pneumonia. The long-term recovery from parapneumonic empyema seems to be good with current treatment strategies.