Hospital Outbreak

Irene Matthews, an infection control nurse has 3 patients in her hospital that have all contracted post-procedure bacterial septicemia.  All 3 have fevers and low blood pressure.  These 3 patients are in separate areas of the hospital, in different units, and they have all undergone different procedures. As far as Irene can tell, the only thing these patients have in common is the infectious agent, Klebsiella pneumoniae. 

Irene reviewed what she knows about gram-negative K. pneumoniae bacteria.  Although this bacteria is part of normal intestinal microbiota, outside its typical environment it can cause serious infection.  K. pneumoniae accounts for about 8% of all health-care associated infections.  Irene surmises that the bacteria had to come from the hospital somewhere.

1. Why does Irene believe the bacteria came from the hospital somewhere? 
2. What is causing the patients’ fever and low blood pressure?

As Irene was checking on the patients she noticed another patient being feed ice chips by a relative. On a hunch, Irene requests that the ice machines be swabbed and cultured.  Her hunch turns out correct: the samples are positive for K. pneumoniae. Bacteria growing in the hospital’s water pipes entered the ice machine with incoming water.

1. How canK. pneumoniaegrow in water pipes?
2. Why weren’t more people (i.e. medical staff) in the hospital sick?
3. In your opinion, how could similar outbreaks be prevented at this hospital in the future?

Reference: Hospital Outbreak Case Study found in Chapter 11 of Tortora, G. J. (2011). Microbiology: An introduction (11th ed.). San Francisco, CA: Benjamin Cummings.