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A Flavobacterium meningosepticum outbreak among intensive care patients
M Pokrywka1, K Viazanko, J Medvick
1Department of Infection Control, Presbyterian University Hospital, Pittsburgh, PA.
Abstract:
A Flavobacterium meningosepticum outbreak, involving 12 infected and 47 colonized intensive care patients during the months of February through July 1990, was investigated. F. meningosepticum was isolated from tap water and ice, but these environmental strains eventually proved to be distinct from those colonizing patients. A review of newly colonized patients' charts revealed that a common factor among the patients was daily changes of ventilator tubing pasteurized in the hospital's central sterile department. More than 90% of patients in the outbreak had been on ventilators that used the pasteurized tubing. An investigation of the pasteurization process found that two pasteurizer tanks had been operating at suboptimal temperatures (< 62 degrees C). Cultures of water from the tanks and droplets of water found in the pasteurized tubing grew species of Acinetobacter, Moraxella, and Pseudomonas but did not grow F. meningosepticum. After deficiencies in the pasteurization process were corrected, the outbreak terminated. Despite the failure to culture F. meningosepticum, an analysis of gram-negative bacillary isolates showed that the deficiency in the pasteurization process was a major contributor to colonization of ventilated patients by bacteria ubiquitous in tap water.
Insights
An intensive care unit outbreak of Flavobacterium meningosepticum was linked to contaminated pasteurized ventilator tubing. Correcting pasteurization temperatures stopped the spread of bacteria, highlighting the importance of proper sterilization in preventing patient infections.
Area of Science:
- Infectious Diseases
- Hospital Epidemiology
- Microbiology
Background:
- An outbreak of Flavobacterium meningosepticum occurred in an intensive care unit (ICU) between February and July 1990.
- The outbreak involved 12 infected and 47 colonized patients, necessitating an investigation into the source and transmission routes.
Purpose of the Study:
- To identify the source and transmission pathway of Flavobacterium meningosepticum during the ICU outbreak.
- To determine the role of pasteurized ventilator tubing in patient colonization and infection.
Main Methods:
- Environmental sampling of tap water and ice.
- Review of patient charts to identify common factors among newly colonized individuals.
- Investigation of the hospital's central sterile department's pasteurization process for ventilator tubing.
- Microbiological cultures of pasteurizer tanks and tubing water.
Main Results:
- Flavobacterium meningosepticum was isolated from environmental sources but was distinct from patient strains.
- A common factor identified was the daily use of pasteurized ventilator tubing.
- Suboptimal pasteurization temperatures (< 62°C) were found in two pasteurizer tanks.
- Water from tanks and tubing grew Acinetobacter, Moraxella, and Pseudomonas, but not F. meningosepticum.
- The outbreak ceased after correcting deficiencies in the pasteurization process.
Conclusions:
- Despite not culturing F. meningosepticum from the faulty pasteurization system, the evidence strongly implicates it.
- Deficiencies in the pasteurization process significantly contributed to the colonization of ventilated patients by common tap water bacteria.
- Proper temperature control during pasteurization is critical for preventing healthcare-associated infections.