Nasopharyngeal detection of atypical bacteria by multiplex polymerase chain reaction panel in acutely ill children was associated with an increased risk of pneumonia

Aim We aimed to assess whether detection of respiratory bacteria by multiplex polymerase chain reaction (PCR) testing associates with clinical outcomes in acutely ill children. Methods This cross‐sectional study enrolled children under the age of 18 with a suspected respiratory infection treated in a paediatric emergency department of Oulu University Hospital, Finland from January 2015 through December 2015. Nasopharyngeal samples were routinely analysed for 16 respiratory viruses and later, after storage, analysed with a multiplex PCR panel for seven respiratory bacteria. Results At least one bacterial pathogen was detected in 600 out of the 1195 children (50%). The mean age was 3.3 (SD 3.7) years and 54% were boys. Atypical bacteria were associated with a risk of pneumonia (adjusted odds ratio [aOR] 14.1, 95% CI 3.98–50.1). Co‐detection of rhinovirus with Streptococcus pneumoniae was not associated with risk of pneumonia (aOR 2.39, 95% CI 0.78–7.30). Detection of Streptococcus pneumoniae, Haemophilus influenzae or both was not associated with the risk of hospital admission or prescription of antibiotics. Conclusion Nasopharyngeal detection of atypical bacteria in acutely ill children was associated with a markedly increased risk of pneumonia. The clinical utility of wide testing for other respiratory bacteria needs further evaluation.