Infection with Ureaplasma urealyticum: is there a specific clinical and radiological course in the preterm infant?

Abstract

Background: Despite having mild early respiratory disease, many preterm babies develop chronic lung disease (CLD). Intrauterine infection with Ureaplasma urealyticum has been associated with preterm labour and CLD. Objective: To test the hypothesis that infection with U urealyticum results in a specific clinical and radiological picture in the first 10 days of life. Methods: Retrospective study of 60 ventilated babies , 30 weeks gestation, who had tracheal secretions tested for U urealyticum. Placental histology was reviewed by a paediatric pathologist for signs of chorioamnionitis. Chest radiographs were independently reviewed by two paediatric radiologists according to previously agreed criteria. All reviewers were blinded to the infection status of the babies. Results: Twenty five babies were U urealyticum positive. These were more likely to experience chorioamnionitis (p = 0.004), premature rupture of membranes (p = 0.01), and spontaneous vaginal delivery (p = 0.09). U urealyticum positive babies had fewer signs of respiratory distress syndrome on early chest radiographs (p = 0.038), and they could be weaned from their ventilation settings (fraction of inspired oxygen (FIO 2 ) and mean airway pressure) more quickly in the first few days. Subsequently U urealyticum positive babies deteriorated clinically and radiologically. More often they required ventilation to be restarted (p = 0.051), a higher proportion being ventilated on day 10 (p = 0.027) with higher FIO 2 (p = 0.001) and mean airway pressure (p = 0.002). Their chest radiographs showed more emphysematous changes as early as day 5 (p = 0.045), with a pronounced difference by day 10 (p = 0.009). Conclusions: Preterm ventilated babies with U urealyticum in their tracheal secretions have a different clinical and radiological course, with less acute lung disease but early onset of CLD, compared with those with negative cultures.

Experimental amniotic fluid infection in sheep: Effects of Ureaplasma parvum serovars 3 and 6 on preterm or term fetal sheep

“…has recently been described (20). After few initial signs of respiratory distress syndrome and earlier weaning from ventilators than ureaplasma-negative infants, ureaplasma-positive infants have an increased risk of requiring reestablishment of ventilatory support, greater subsequent ventilatory requirements and radiological evidence of emphysematous change (20). Another finding of our study that is consistent with data from human patients is the elevated amniotic fluid IL-8 concentrations in the presence of amniotic fluid colonization (21).…”

“…Increased surfactant and lung compliance in preterm lambs exposed to ureaplasmas are consistent with data from human infants, which show a reduction in the risk of respiratory distress syndrome in the presence of airway (and likely antenatal) colonization (4,20). The clinical course of a group of infants with tracheal aspirate samples positive for Ureaplasma spp.…”

“…The clinical course of a group of infants with tracheal aspirate samples positive for Ureaplasma spp. has recently been described (20). After few initial signs of respiratory distress syndrome and earlier weaning from ventilators than ureaplasma-negative infants, ureaplasma-positive infants have an increased risk of requiring reestablishment of ventilatory support, greater subsequent ventilatory requirements and radiological evidence of emphysematous change (20).…”

Mycoplasmas and Ureaplasmas as Neonatal Pathogens

“…A second retrospective study of 25 preterm infants whose tracheal secretions were culturally positive for Ureaplasma spp. and who had received mechanical ventilation found that while Ureaplasma-positive had fewer signs of respiratory distress initially, they were more likely to deteriorate clinically and radiologically and often required mechanical ventilation to be resumed (295). Chest radiographs of Ureaplasma-positive infants showed evidence of emphysematous changes as early as 5 days with a pronounced difference by day 10, supporting the earlier findings of Crouse et al (60).…”

Plasma KL-6 Predicts the Development and Outcome of Bronchopulmonary Dysplasia

“…These "fulminant" cases may be more similar to Japanese infants who have been reported as "neonatal pulmonary emphysema" (37), while a milder case has been reported in a relatively mature infant (38). A recent report from the UK also described similar emphysematous changes from as early as 5 d after birth in extremely premature infants and suggested a close association with colonization by Ureaplasma urealyticum (39). However, the condition of these infants seemed to be much milder since the median duration of ventilation was only 33 d (versus 76 d in our seven infants).…”