Outbreak of severe Pseudomonas aeruginosa infections caused by a contaminated drain in a whirlpool bathtub

Clin Infect Dis. 2000 Dec;31(6):1331-7. doi: 10.1086/317501. Epub 2000 Nov 29.


During a 14-month period, 7 patients with hematological malignancies acquired serious infections caused by a single strain of multiply resistant Pseudomonas aeruginosa. A case-control study, culture surveys, and pulsed-field gel electrophoresis implicated a whirlpool bathtub on the unit as the reservoir. All case patients and 32% of control patients used this bathtub (P=.003). The epidemic strain was found only in cultures of samples taken from the bathtub. The drain of the whirlpool bathtub, which was contaminated with the epidemic strain, closed approximately 2.54 cm below the drain's strainer. Water from the faucet, which was not contaminated, became contaminated with P. aeruginosa from the drain when the tub was filled. The design of the drain allowed the epidemic strain to be transmitted to immunocompromised patients who used the whirlpool bathtub. Such tubs are used in many hospitals, and they may be an unrecognized source of nosocomial infections. This potential source of infection could be eliminated by using whirlpool bathtubs with drains that seal at the top.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Bacterial Agents / pharmacology
  • Case-Control Studies
  • Cross Infection / epidemiology*
  • Cross Infection / microbiology
  • Cross Infection / transmission
  • Culture Media
  • Disease Outbreaks*
  • Drainage, Sanitary*
  • Drug Resistance, Microbial
  • Drug Resistance, Multiple
  • Electrophoresis, Gel, Pulsed-Field
  • Equipment Contamination*
  • Hematologic Neoplasms / complications
  • Humans
  • Hydrotherapy / instrumentation*
  • Immunocompromised Host
  • Male
  • Middle Aged
  • Pseudomonas Infections / epidemiology*
  • Pseudomonas Infections / microbiology
  • Pseudomonas Infections / transmission
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / isolation & purification*


  • Anti-Bacterial Agents
  • Culture Media