Outbreak of pneumocystis jiroveci pneumonia among renal transplant patients

Pneumocystis jiroveci pneumonia(PJP) is an important cause of morbidity and mortality in renal transplant recipients (RTRs). The epidermiology and pathogenesis of this infection are poorly understood, and the exact mode of transmission remains unclear. In general, reactivation of latent infection was considered the mechanism of infection. However, recent studies reported clusters or outbreaks of PJP among immunocompromised patients as RTRs, interhuman transmission has been suggested. We experienced 9 consecutive development cases with PJP from May to December 2012 despite no occurrence of PJP in the past 10 years. These 9 cases consisted of 7 males and 2 females. The age range of patients was 30–74 years (mean age: 54.7 years). The interval from the renal transplantation was 1.3–11.5 years (mean: 5.8 years). In all cases, patients visited our hospital due to symptoms such as fever, cough, and shortness of breath. CT images shows diffuse ground-glass opacity in both lung. In blood examination, β-d glucan was 37-1319 (mean: 376) pg/ml. In 8 patients, on admission we had bronchial endoscopy and investigated with segmental alveolar lavage. Pneumocystis carinii -PCR was positive in all cases. Among these, 4 cases were established a diagnosis using cytology by Grocott methanamine silver staining. Trimethoprim-Sulfamethoxazole was administered to all patients, 8 patients were discharged, but 1 patient died. The route of Pneumocystis jiroveci infection remains uncertain. The clustering of PJP suggests that possibility of nosocomial transmission.