Critical colonization--the concept under scrutiny.

Infection in chronic wounds presents a major clinical challenge and is a cause of high morbidity rates. Much attention has been dedicated to identifying and managing this problem since the publication of the first article on chronic wound infection criteria in 1994. To illustrate how alteration in wound bioburden impacts pathology, the Wound Infection Continuum has been devised and subsequently modified. One stage in this continuum, critical colonization, is putatively described as a pivotal phase that occurs without inducing an overt host response. Critical colonization suggests that the concept is currently better explained from a microbiological than from a clinical perspective. The status of critically colonized wounds may change in one of several ways: 1) deteriorate to clinical infection, 2) remain in a critically colonized state, or 3) improve following appropriate intervention. Research to clearly define the term and clarify the role of bioburden in the chronic wound is needed to help clinicians recognize and implement appropriate treatment.