Ureaplasma and CLD

Patterns of Colonization With Ureaplasma urealyticum During Neonatal Intensive Care Unit Hospitalizations of Very Low Birth Weight Infants and the Development of Chronic Lung Disease Castro-Alcaraz S, Greenberg EM, Bateman DA, et al. PEDIATRICS Vol. 110 No. 4 October 2002, pp. e45

Background: Ureaplasma urealyticum and its association withchronic lung disease (CLD) of prematurity have remained a controversialtopic. To readdress this question, we performed a longitudinalstudy using culture and polymerase chain reaction to detectU urealyticum in the respiratory tract of very low birth weightinfants throughout their neonatal intensive care unit hospitalizations.

Methods: We screened 125 infants weighing <1500 g and/or<32 weeks’ gestational age over a 12-month period,collecting endotracheal, nasopharyngeal, and throat specimenson days of age 1, 3, 7, and weekly thereafter. CLD was definedas dependency on supplemental oxygen at 28 days and at 36 weeks’postconceptional age.

Results: Forty infants (32%) had 1 or more positive specimensby culture or polymerase chain reaction. We identified 3 patternsof U urealyticum colonization: persistently positive (n = 18),early transient (n = 14), and late acquisition (n = 8). We comparedthe rates of CLD in each of the 3 colonized groups with therate of CLD in the noncolonized group. We found a significantlyhigher rate of CLD at 28 days of age (odds ratio: 8.7; 95% confidenceinterval: 3.3, 23) and at 36 weeks’ postconception (oddsratio: 38.5, 95% confidence interval: 4.0, 374) only for infantswith persistently positive colonization.

Conclusions: This study demonstrates that the risk of developingCLD varies with the pattern of U urealyticum colonization. Onlythe persistently positive colonization pattern, which accountedfor 45% of the U urealyticum-positive infants, was associatedwith a significantly increased risk of development of CLD.

Comment: While this study does not prove a causal relationship between persistent Ureaplasma colonization and the development of CLD, the association is certainly suspicious. This organism has been shown to cause an inflammatory response in the premature lung that can lead to CLD. Will treatment to eradicate Ureaplasma colonization from persistent carriers reduce their risk of CLD? That’s the next question we need to study! ABK.