title: Corynebacterium diphtheriae and the returned tropical traveler.
abstract: BACKGROUND
  In Western countries, nontoxigenic Corynebacterium diphtheriae is known to cause skin and soft tissue infections (SSIs), upper respiratory tract infections, and occasionally invasive disease. Its role as a skin pathogen in returned travelers from tropical destinations where the organism is endemic is often forgotten. A retrospective analysis of a large Australian private pathology laboratory's experience with C. diphtheriae was performed to identify how frequently overseas travel was associated with C. diptheriae infection/colonization.
  
  
  METHODS
  All C. diphtheriae isolates cultured from 2002 to 2012 were reviewed. Recorded clinical information regarding recent travel, country, and cause of infection was assessed. Antibiotic susceptibility was verified on all isolates.
  
  
  RESULTS
  In all there were 72 patients who had C. diphtheriae isolated on clinical specimens, and information about prior travel was available for 63. Seventy percent of these were healthy individuals with an SSI and history of recent travel to a tropical nation. Ninety-seven percent had associated copathogens. Two isolates were penicillin resistant. There was uniform susceptibility to cephalothin, clindamycin, erythromycin, and vancomycin, with 14% resistance to trimethoprim/sulfamethoxazole and 4% resistance to tetracycline. Only one isolate was a toxigenic strain.
  
  
  CONCLUSIONS
  The majority of C. diphtheriae isolated were from SSIs in otherwise healthy travelers returning from tropical destinations, rather than classical risk groups. Clinicians and laboratories need to be aware of this potential source of C. diphtheriae infection due to rare toxigenic strains.
authors.affiliation: Department of Microbiology, Sullivan Nicolaides Pathology, Brisbane, QLD, Australia.
authors.forename: Meryta L A
authors.initials: ML
authors.lastname: May
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: McDougall
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Robson
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001315:Australia / Q000453:epidemiology; D002675:Child, Preschool; D003353:Corynebacterium diphtheriae / Q000187:drug effects / Q000302:isolation & purification; D004165:Diphtheria / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D004167:Diphtheria Toxin / Q000097:blood; D019353:Endemic Diseases / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D017063:Outcome Assessment, Health Care; D010403:Penicillin Resistance; D012189:Retrospective Studies; D012307:Risk Factors; D014195:Travel; D014329:Tropical Climate
chemical_list: D000900:Anti-Bacterial Agents; D004167:Diphtheria Toxin