title: Outbreaks of Pneumocystis pneumonia in 2 renal transplant centers linked to a single strain of Pneumocystis: implications for transmission and virulence.
abstract: BACKGROUND
  There have been numerous reports of clustered outbreaks of Pneumocystis pneumonia (PCP) at renal transplant centers over the past 2 decades. It has been unclear whether these outbreaks were linked epidemiologically to 1 or several unique strains, which could have implications for transmission patterns or strain virulence.
  
  
  METHODS
  Restriction fragment length polymorphism (RFLP) analysis was used to compare Pneumocystis isolates from 3 outbreaks of PCP in renal transplant patients in Germany, Switzerland, and Japan, as well as nontransplant isolates from both human immunodeficiency virus (HIV)-infected and uninfected patients.
  
  
  RESULTS
  Based on RFLP analysis, a single Pneumocystis strain caused pneumonia in transplant patients in Switzerland (7 patients) and Germany (14 patients). This strain was different from the strain that caused an outbreak in transplant patients in Japan, as well as strains causing sporadic cases of PCP in nontransplant patients with or without HIV infection.
  
  
  CONCLUSIONS
  Two geographically distinct clusters of PCP in Europe were due to a single strain of Pneumocystis. This suggests either enhanced virulence of this strain in transplant patients or a common, but unidentified, source of transmission. Outbreaks of PCP can be better understood by enhanced knowledge of transmission patterns and strain variation.
authors.affiliation: Critical Care Medicine Department, National Institutes of Health Clinical Center, Bethesda, Maryland 20892-1662, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Sassi
authors.forename: Chiara
authors.initials: C
authors.lastname: Ripamonti
authors.forename: Nicolas J
authors.initials: NJ
authors.lastname: Mueller
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Yazaki
authors.forename: Geetha
authors.initials: G
authors.lastname: Kutty
authors.forename: Liang
authors.initials: L
authors.lastname: Ma
authors.forename: Charles
authors.initials: C
authors.lastname: Huber
authors.forename: Emile
authors.initials: E
authors.lastname: Gogineni
authors.forename: Shinichi
authors.initials: S
authors.lastname: Oka
authors.forename: Norihiko
authors.initials: N
authors.lastname: Goto
authors.forename: Thomas
authors.initials: T
authors.lastname: Fehr
authors.forename: Sara
authors.initials: S
authors.lastname: Gianella
authors.forename: Regina
authors.initials: R
authors.lastname: Konrad
authors.forename: Andreas
authors.initials: A
authors.lastname: Sing
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Kovacs
mesh_terms: D016000:Cluster Analysis; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D005838:Genotype; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016030:Kidney Transplantation / Q000009:adverse effects*; D058889:Molecular Typing; D016533:Mycological Typing Techniques; D011010:Pneumocystis / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity*; D011020:Pneumonia, Pneumocystis / Q000453:epidemiology* / Q000382:microbiology* / Q000635:transmission; D012150:Polymorphism, Restriction Fragment Length; D013557:Switzerland / Q000453:epidemiology; D014774:Virulence