Department of Renal Medicine, Westmead Hospital, Westmead, NSW, Sydney, Australia.
Transplantation. 2011 Dec 27;92(12):1327-34. doi: 10.1097/TP.0b013e3182384b57.
Pneumocystis jirovecii pneumonia (PJP) is an important infection-related complication, whose mode of transmission remains uncertain.
We investigated a nosocomial cluster of 14 PJP cases (11 confirmed and 3 probable) in kidney transplant recipients using epidemiological and genotyping methods.
Poisson regression calculated an incidence density ratio of 42.8 (95% confidence interval [CI], 14.1-129.3) versus background 0.64 cases of 1000 patient-years (P<0.001). All patients presented with respiratory failure, 10 required ventilation, two died, and six transplants failed, costing $31,854 (±SD $26,048) per patient. Four-locus multilocus sequence typing analysis using DNA extracts from 11 confirmed cases identified two closely related genotypes, with 9 of 11 sharing an identical composite multilocus sequence typing genotype. Contact tracing found colocalization of cases within clinic waiting areas, suggesting person-to-person transmission. Minimal and maximal PJP incubation periods were 124±83 to 172±71 days, respectively. Oropharyngeal washes from outpatient staff and ambient air samples were negative for P. jirovecii DNA. Cohort analysis (14 cases vs. 324 unaffected clinic control patients) identified independent risk factors including previous cytomegalovirus infection (odds ratio [OR], 65.9; 95% CI, 7.9-550; P<0.001), underlying pulmonary disease (OR, 10.1; 95% CI, 2.3-45.0; P=0.002), and transplant dysfunction (OR=1.61 per 10 mL/min/1.73 m, 95% CI, 1.15-2.25, P=0.006). The outbreak was controlled by reintroduction of trimethoprim/sulfamethoxazole prophylaxis to all potentially exposed clinic patients and its extension to 12 months in recent recipients.
Nosocomial PJP clusters are likely due to interhuman transmission by airborne droplets to susceptible hosts. Prompt recognition and a strategy of early preemptive blanket PJP prophylaxis to all exposed transplant clinic recipients from the third confirmed case are recommended to limit outbreak escalation.
卡氏肺孢子虫肺炎（PJP）是一种重要的感染相关并发症，其传播方式仍不确定。
我们使用流行病学和基因分型方法调查了 14 例肾移植受者中发生的医院感染群集性卡氏肺孢子虫肺炎（PJP）病例（11 例确诊，3 例可能）。
泊松回归计算出的发病率密度比为 42.8（95%置信区间[CI]，14.1-129.3），而背景中每 1000 患者年发生 0.64 例（P<0.001）。所有患者均出现呼吸衰竭，10 例需要通气，2 例死亡，6 例移植失败，每位患者的费用为 31854 美元（±SD 26048 美元）。使用 11 例确诊病例的 DNA 提取物进行的 4 基因座多位点序列分型分析确定了两种密切相关的基因型，其中 11 例中有 9 例具有相同的复合多位点序列分型基因型。接触追踪发现病例在诊所候诊区的位置接近，提示人与人之间的传播。最小和最大卡氏肺孢子虫肺炎潜伏期分别为 124±83 至 172±71 天。门诊工作人员的咽拭子和环境空气样本均未检测到卡氏肺孢子虫 DNA。队列分析（14 例病例与 324 例未受影响的诊所对照患者）确定了独立的危险因素，包括既往巨细胞病毒感染（比值比[OR]，65.9；95%CI，7.9-550；P<0.001）、基础肺部疾病（OR，10.1；95%CI，2.3-45.0；P=0.002）和移植功能障碍（每 10 毫升/分钟/1.73 米增加 1.61，95%CI，1.15-2.25，P=0.006）。通过重新向所有潜在暴露的诊所患者引入复方磺胺甲噁唑预防性治疗，并将其扩展至最近接受移植的患者 12 个月，从而控制了该暴发。
医院获得性 PJP 群集可能是由于空气中飞沫传播给易感宿主。建议从第 3 例确诊病例开始，立即识别并对所有暴露于移植诊所的受者进行早期预防性普适性 PJP 预防，以限制暴发升级。
