Branhamella catarrhalis bronchopulmonary isolates in PICU patients

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.

Changes in genetic types and population dynamics of Moraxella catarrhalis in hospitalized children are not associated with an exacerbation of existing disease

Pulsed-field gel electrophoresis typing was performed on a retrospective set of 129 Moraxella catarrhalis isolates obtained over a 20 month period from 70 children admitted to, or presenting at, the Erasmus University Medical Center, Rotterdam, The Netherlands. The mean age of the children (at the end of the study) was 2.5 years, with a range of 6 months to 15 years. Fifty-one different M. catarrhalis types were isolated from the hospitalized children, with 31 % (22/70) being infected with two particularly prevalent M. catarrhalis types. These two prevalent types also exhibited different protein profiles. The majority (72%; 16/22) of the children infected with these two predominant types had spent at least 1 week on two paediatric intensive care wards. No exacerbation of existing disease or new disease was observed in children who experienced M. catarrhalis type changes.

Infraglottic and bronchial infections

Concerns over infraglottic and bronchial infections have been a source of anxiety and lost sleep for many children, parents, and physicians. The annual incidence of lower respiratory tract infections in children younger than 6 years old exceeds 5 million in the United States. Despite the frequency of these infections, the often common and nonspecific clinical symptomatology, variable severity, and changing epidemiology over time all have contributed to our understanding and misunderstanding of these disorders.

Bronchopulmonary infection with Moraxella catarrhalis in infants requiring extracorporeal membrane oxygenation

Moraxella (formerly Branhamella) catarrhalis is now a well-recognized pathogen of the upper and lower respiratory tract. Four pediatric cases of life-threatening pneumonia requiring extracorporeal membrane oxygenation are presented. M. Catarrhalis was isolated within 48 hours of admission in three of the cases and within 24 hours of an acute deterioration in the fourth. We conclude that M. catarrhalis is either a significant pathogen in its own right, a marker of severe disease, or a secondary invader.

Role of Moraxella (Branhamella) catarrhalis as a respiratory pathogen in children

During a 12-month surveillance period in 1981-1982, Moraxella catarrhalis was detected in cultures from nasopharyngeal aspirates from 76 (17%) of 449 children hospitalized with middle or lower respiratory tract infection. Seroconversion to M. catarrhalis was positive in 4 (5%) of the 76 patients with M. catarrhalis present in nasopharyngeal aspirates and in 4 (1%) of 373 patients with a negative finding. Although children with respiratory tract infections were often colonized by the organism, this was rarely the infective agent of the middle or lower airways. Four of 8 patients with seroconversion to M. catarrhalis exhibited a concomitant RSV infection. The carriage of this species was more closely associated with parainfluenza virus infections. Serological responses to M. catarrhalis were not associated with acute otitis media, and were also rare in children with pneumonia. It is concluded that bronchopulmonary infections caused by M. catarrhalis are rare in children, and that M. catarrhalis aetiology need not be considered in the selection of antibiotics in cases of community-acquired pneumonia or other infections of the middle or lower respiratory tract affecting primarily healthy children.

Branhamella catarrhalis colonization in preschool asthmatics

Branhamella catarrhalis has been associated with exacerbations of chronic bronchitis and asthma in adults. To investigate the possible role of B. catarrhalis in asthma of early childhood, we took posterior pharyngeal swabs from 24 normal children, 20 well asthmatics, and 20 acutely wheezy asthmatics, all between 1 and 4 years of age. On culture, 33% of the normal children were colonized with B. catarrhalis; colonization rates in the well asthmatics (70%) and in the wheezy asthmatics (75%) were significantly higher than in normals. The nature of this association requires further study.

Molecular epidemiological characterization of respiratory isolates of Moraxella catarrhalis in a pediatric intensive care unit

A perceived increase in the number of isolates of Moraxella catarrhalis from the respiratory secretions of patients intubated in the pediatric intensive care unit prompted a review of the clinical profiles of such patients and restriction enzyme analysis of the strains involved. Over two months, of 192 patients admitted to the unit, 154 were intubated. Of the 46 for whom endotracheal tube specimens were submitted to the laboratory, M catarrhalis was isolated in 12. M catarrhalis was not felt to be a significant respiratory pathogen by the attending medical staff in any of the patients from whom it was isolated. In only two patients (17%) could nosocomial acquisition be firmly invoked. Restriction enzyme analysis of the 12 strains ruled out the presence of an epidemic strain. Isolation of M catarrhalis from intubated children does not necessarily imply pathogenicity nor an outbreak situation.