[Ureaplasma urealyticum and pertussis-like syndrome]

Ureaplasma urealyticum is associated with respiratory pathology in the neonates and preterm neonates. However, this association has been poorly studied in infants and during early infancy. To address this issue, a clinic evaluation of patients with whooping cough and isolation of U. urealyticum in their nasopharyngeal aspirates has been done.

Over a period of 11 years, 1063 nasopharyngeal aspirates from 905 infants were studied. Clinical samples were cultured for Bordetella spp., other bacteria, viruses and mycoplasma. Data of patients with positive cultures for U. urealyticum were obtained from clinical records.

U. urealyticum was isolated from 26 patients with a median age of 5 months (range: 23 days-22 months). The gestational age of 9 patients (34.6%) was less than 37 weeks. All the patients were hospitalised because of pertussis-like syndrome, which was associated with respiratory distress due to bronchospasm in 18 patients (69.2%). Twelve patients (46.1%) had fever and 15 (57.7%) showed lymphocytosis. The chest roentgenogram was abnormal in 18 patients (69.2%): pulmonary hyperaeration, with or without atelectasis. Clinical evolution was good in all patients. In 16 patients (61.5%) U. urealyticum was isolated together with other microorganisms: in 9 samples with bacteria (H. influenzae, S. pneumoniae, B. pertussis, M. catarrhalis), in 5 with viruses (respiratory syncytial virus, cytomegalovirus, adenovirus, enterovirus) and in 2 samples with respiratory syncytial virus and S. pneumoniae and B. pertussis respectively.

Likely U. urealyticum cannot be considered clearly as the etiologic agent of whooping cough, mainly because in the 61.5% of patients U. urealyticum has been isolated together with other microorganisms considered pathogens or potentially pathogens. Future studies would be necessary in order to establish the pathogenic role of U. urealyticum after the neonatal period.