The clinical characteristics, treatment and outcome of macrolide-resistant Mycoplasma pneumoniae pneumonia in children

Abstract

To investigate the drug resistance of Mycoplasma pneumoniae among children with community-acquired pneumonia (CAP), and to explore the clinical and radiological characteristics of and the role of azithromycin in the treatment of of macrolide-resistant (MR) Mycoplasma pneumoniae pneumonia. Cases of CAP in children (n = 179) were prospectively enrolled in the Pediatric ward of Beijing Chaoyang Hospital from 1st September, 2010 to 31st August 2011. Pharyngeal swabs were collected for detection of Mycoplasma pneumoniae DNA. Mycoplasma pneumoniae culture and in vitro susceptibility testing were also performed. Eighty-three cases met the diagnostic criteria of mycoplasma pneumonia, accounting for 46% of the CAP patients. Mycoplasma pneumoniae culture was positive in 45 cases, including 44 highly resistant to macrolides (MR) in vitro, and 1 sensitive. The 44 cases caused by MR pathogen presented with fever for (8 ± 3) d and cough for (17 ± 5) d, with higher fever (39.5 ± 0.7) °C and more irritating dry cough. In most of the children, peripheral blood leukocytes (8 ± 4)×10(9)/L were normal, with normal or elevated (0.60 ± 0.94) neutrophils, normal or slightly elevated erythrocyte sedimentation rate [(24 ± 14) mm/1 h] and CRP (12.8 mg/L). Chest X-ray showed lobar consolidation in 10 cases (23%, 10/44), among them 3 in the lower left lung, 2 in the left lung, 3 in the right lower lung, 2 in the right upper lung. Pleural effusion (small amount), combined with right lower lung consolidation, was found in 1 case. Patchy shadows were found in 27 cases, and interstitial lung infiltrate in 7 cases. Of the 44 cases caused by MR Mycoplasma pneumoniae, 19 had lung computed tomography (CT) scanning, among them 13 had lobar or segmental consolidation. Azithromycin therapy started in an average of 4.0 days after onset of illness, with duration of therapy averaging (9 ± 4) d. Cephalosporin or penicillin (n = 1) was the initial antibiotic choice in 12 of them, while combination therapy with azithromycin and cephalosporin or penicillin antibiotics was given in 41 of them. The duration of fever averaged (6 ± 3) d after treatment of azithromycin and duration of cough averaged (17 ± 5) d after treatment. Among patients with MR Mycoplasma pneumonia, those with lobar consolidation had longer duration of fever after treatment with azithromycin, compared with those without consolidation (P < 0.05). The macrolide resistance rate was 98% (44/45) in our patients. Fever and duration of therapy with azithromycin in MR infection was longer in patients with lobar consolidation. The 44 children with MR Mycoplasma pneumonia recovered with no serious complications.