The pathogenic significance of Branhamella catarrhalis

Community-acquired Moraxella catarrhalis pneumonia in previously healthy children

BACKGROUND

The aim of this study was to determine if Moraxella catarrhalis is a common cause of community acquired pneumonia in children with no chronic medical problems. A secondary goal was to describe the clinical features of children with M. catarrhalis pneumonia.

METHODS

A systematic literature search was conducted for (i) case series of pediatric community-acquired pneumonia (CAP) where one or more diagnostic tests for M. catarrhalis were applied to all cases and (ii) case reports of previously healthy children with proven M. catarrhalis pneumonia.

RESULTS

There were nine case series describing a total of 1,500 children with CAP. The number of children tested and yield was as follows: blood cultures 0/402 (0%); sputum cultures 15/157 (10%); nasopharyngeal, or postnasal cultures 129/521 (25%); sputum or nasopharyngeal cultures 0/74 (0%) (one study allowed either); nucleic acid amplification testing 2/100 (2%); serology 30/976 (3%). There were eight case reports of CAP with M. catarrhalis in previously well children. Children were ages 3 weeks to 7 years of age (median 14 months). Six of 8 (75%) children required mechanical ventilation. All survived.

CONCLUSION

It is common to detect M. catarrhalis in upper respiratory secretions in children with pneumonia, but bacteremia or seroconversion is rare. There are only eight well-documented case reports CAP due to M. catarrhalis in previously well children, with there being no distinctive features in the eight cases described to date. This organism is likely a rare cause of CAP in previously healthy children.