Objective: To investigate the clinical characteristics of ureaplasma urealyticum(UU) pneumonia in preterm infants less than 32 weeks. Methods: Preterm infants with gestational age <32 weeks who were hospitalized in neonatal intensive care unit (NICU) of Peking University Third Hospital from January 2018 to December 2019 were retrospectively analyzed. There were 105 premature infants, 63 males and 42 females. After the first diagnosis of pneumonia during hospitalization, the airway secretions were collected for UU nucleic acid detection. They were divided into UU positive group and UU negative group. Perinatal factors, comorbidities, antibiotic treatment and clinical outcomes were compared between the two groups. SPSS24.0 statistical software was used for statistical analysis. T test or chi-square test was used to compare the two groups, and logistic regression was used for multivariate analysis. Results: Among 105 cases of preterm pneumonia, 37 cases (35.2%) were diagnosed with UU pneumonia and 68 cases (64.8%) were negative for UU test. There was no significant difference in gestational age [28(27,30) weeks vs 29(28,30)weeks,Z=-0.98, P>0.05] and birth weight[(1 282.03±292.49)g vs (1 196.62±322.89)g,t=1.34, P>0.05] between the two groups. In UU pneumonia group, the rate of singleton (86.5% vs 50%,χ2=12.15), chorioamnionitis (10.8% vs 1.55%,χ2=4.61), premature rupture of membranes>12 h (32.4% vs 11.8%,χ2=5.37) and vaginal delivery rate(59.5% vs 35.3%,χ2=4.75) were higher than UU negative group (P<0.05). Further multivariate logistic regression analysis showed that vaginal delivery was an independent risk factor for UU (OR = 2.694, 95%CI: 1.113-6.525). WBC count in UU positive group was significantly higher [12.85×109/L (9.32×109/L,17.22×109/L) vs 9.06×109/L (7.06×109/L,13.37×109/L), Z=-3.01, P<0.05], and oxygen consumption time was prolonged[ (46.8±19.8)d vs (37.8±20.7)d, t=2.177,P<0.05]. The incidence of hemodynamically significant patent ductus arteriosus (29.7% vs 57.4%,χ2=6.265) and respiratory distress syndrome (54.1% vs 75.0%,χ2=4.801) in UU positive group was significantly lower than that in UU negative group (P<0.05). There was no significant difference in bacterial infection(62.2% vs 50.0%, χ2=8.826) and antibiotic(48.6% vs 47.1%,χ2=1.352) between the two groups(all P>0.05). After azithromycin treatment, the time for UU negative was (9.00±3.14) days. There was no significant difference in the incidence of bronchopulmonary dysplasia(73.0% vs 69.1%,χ2=0.036), retinopathy of prematurity(10.8% vs 26.5%,χ2=2.665), neonatal necrotizing enterocolitis(2.7% vs 1.5%,χ2=0.195), intraventricular periventricular hemorrhage (69.4% vs 72.1%,χ2=0.003) and periventricular leukomalacia (8.1% vs 8.8%,χ2=0.016) between the two groups (P>0.05). Conclusions: If premature rupture of membranes >12 h, combined with chorioamnionitis, and vaginal delivery, preterm infants less than 32 weeks are likely to have an increased risk of UU infection. UU pneumonia in preterm infants less than 32 weeks old was characterized by prolonged oxygen consumption and increased white blood cell count. Oral azithromycin treatment could effectively remove UU and improve prognosis.
目的： 探讨胎龄小于32周早产儿解脲脲原体（UU）肺炎的临床特征。 方法： 回顾性分析北京大学第三医院新生儿重症监护病房2018年1月至2019年12月住院且合并肺炎的出生胎龄<32周早产儿105例，男63例，女42例。住院期间首次诊断肺炎后即留取气道分泌物进行UU核酸检测，分为UU阳性组和UU阴性组，比较两组间围产因素、合并疾病、抗菌素治疗、临床结局等指标，两组间比较采用t检验或卡方检验，Logistic回归进行多因素分析。 结果： 105例早产儿肺炎中，确诊UU肺炎37例（35.2%），UU检测阴性的肺炎68例（64.8%）。UU阳性组与UU阴性组，患儿胎龄 ［28（27，30）周 vs 29（28，30）周，Z=-0.98， P>0.05］ 及出生体重［（1 282.03±292.49）g vs （1 196.62±322.89）g，t=1.34， P>0.05］，差异无统计学意义。UU阳性组与UU阴性组相比，母亲单胎率（86.5% vs 50%，χ2=12.15）、绒毛膜羊膜炎发生率（10.8% vs 1.55%，χ2=4.61）、胎膜早破>12 h比例（32.4% vs 11.8%，χ2=5.37）及阴道分娩率（59.5% vs 35.3%，χ2=4.75）均较高（P<0.05）；进一步的多因素Logistic回归分析显示经阴道分娩是UU阳性的独立危险因素（OR=2.694， 95%CI： 1.113~6.525）。UU阳性组比UU阴性组，白细胞计数明显升高［12.85（9.32，17.22）×109个/L vs 9.06（7.06，13.37）×109个/L，Z=-3.01，P<0.05］；用氧时间延长［（46.8±19.8）d vs （37.8±20.7）d］，差异有统计学意义（t=2.177，P<0.05）；UU阳性组血流动力学显著的动脉导管未闭发生率（29.7% vs 57.4%，χ2=6.265）和新生儿呼吸窘迫综合征发生率（54.1% vs 75.0%，χ2=4.801）低于UU阴性组，差异均有统计学意义（P<0.05）。UU阳性组与UU阴性组相比，细菌培养阴性率（62.2% vs 50.0%， χ2=8.826）以及三代头孢的使用率（48.6% vs 47.1%，χ2=1.352），差异均无统计学意义（P>0.05）。经过阿奇霉素治疗气道分泌物解脲脲原体转阴时间为（9.00±3.14）d；两组间在支气管肺发育不良（73.0% vs 69.1%，χ2=0.036）、早产儿视网膜病（10.8% vs 26.5%，χ2=2.665）、新生儿坏死性小肠结肠炎（2.7% vs 1.5%，χ2=0.195）、脑室内-脑室周围出血（69.4% vs 72.1%，χ2=0.003）和脑室周围白质软化（8.1% vs 8.8%，χ2=0.016）发生率的差异均无统计学意义（P>0.05）。 结论： 胎膜早破时间超过12 h、合并绒毛膜羊膜炎，经阴道分娩出生的小于32周的早产儿，UU感染风险增加。小于32周早产儿UU肺炎，可表现为用氧时间延长，白细胞计数升高，经过口服阿奇霉素治疗后，能够有效清除UU，改善预后。.