BRONCHIAL COLONIZATION AND INFECTION DUE TO MORAXELLA (BRANHAMELLA) CATARRHALIS IN CHILDREN

From January 1, 1995, to June 30, 1997, 25 cytobacteriologic sputum te sts (CBSTs) were positive for Moraxella catarrhalis in 25 inpatients o f a pediatric pneumology department. There were 16 boys and nine girls , with a mean age of 16.8 months and an age range of 2 months to 6 yea rs. The reason for admission was presence of subacute or chronic respi ratory symptoms without cystic fibrosis, including cough of more than one month's duration with or without stasis of respiratory tract secre tions, attacks of dypnea with wheezing, or recurrent lower respiratory tract infections. Sputum samples were required to satisfy four criter ia: (a) gross appearance of a deep respiratory tract sample, (b) bucca l epithelial cell count less than 10 per x 100 field, (c) neutrophil c ount greater than 25 per x 100 field, and (d) organism count of at lea st 10(5) per mi as determined with x 1000 magnification. Focal abnorma lities were seen on the chest radiograph in only five patients, of who m two had lobar pneumonia and three middle lobe syndrome. Evidence of interstitial pneumonia was seen in a 13-month-old. A mild to severe br onchial syndrome was by far the most common finding (91%). Only one pa tient had a normal chest radiograph. Serum C-reactive protein levels w ere moderately elevated in four of 15 cases (26/7%). The absolute peri pheral neutrophil count was 5000 or more per mm(3) in eight cases (42. 1%), with a range of 5022 to 15733 per mm(3). M. catarrhalis was the o nly pathogen in 12 cases (52.2%), with counts ranging from 10(5) to ov er 10(7). Eleven patients (47.8%) had M. catarrhalis and another patho gen: Streptococcus pneumoniae (n=6, including 4 with decreased suscept ibility to penicillin), Haemophilus influenzae (n=4 including 3 with s usceptibility to amoxicillin), Pseudomonas aeruginosa (n=2), Haemophil us parainfluenzae (n=1), Escherichia coli (n=1), and Klebsiella oxytoc a (n=1). All but one of the M. catarrhalis strains were resistant to a moxicillin. When patients with and without other pathogens in addition to M. catarrhalis were compared, no differences were found regarding age, sex, presenting symptoms,;comorbid conditions, or chest radiograp h findings. A review of the literature demonstrated that M. catarrhali s is becoming increasingly important as a cause of pediatric,lower res piratory tract symptoms. M. catarrhalis should be looked for in patien ts with a persistent cough, stasis of respiratory tract secretions, re current bronchitis, acute or chronic focal pulmonary abnormalities, mi ddle lobe syndrome, protracted bronchiolitis, asthma, or exacerbations of bronchopulmonary dysplasia, as well as in ventilated and nonventil ated infants admitted to intensive care units.