Chapter 13.5 : Microbial Strain Typing for Epidemiology and Infection Control

Abstract:

The persistence and transmission of infectious disease constitute one of the most enduring and daunting concerns in health care, including not only in hospitals but also in settings such as nursing homes and assisted living, home health care, and outpatient dialysis centers. These different environments and the multitude of problem bacterial pathogens that may be present represent a challenge for the clinical microbiologist, hospital epidemiologist, and infection control professional as they work together to detect and investigate disease trends and outbreaks. Classical epidemiology uses the parameters of time, place, and person to find links between occurrences of infectious disease. However, these three criteria do not provide the resolution required to fully identify an outbreak event. The clinical microbiology laboratory adds the capability for species-level microbial identification, while molecular analysis (i.e., molecular epidemiology) provides the strain type or subtype. Thus, it is these five parameters (time, place, person, microbial identification, and typing) that together have proved invaluable in providing an accurate picture of microbial persistence and transfer for epidemiologic analysis and infection control. This procedure discusses microbial strain typing, including a simplified list of methods of potential utility to clinical microbiologists. Readers desiring more complete descriptions and/or protocols are referred to more in-depth references on this subject ( 1 , ref13.5_2 – 3 ).