Molecular analysis of relapse vs re-infection in HIV-positive patients suffering from recurrent Clostridium difficile associated diarrhoea.

Recurrence is a major complication of Clostridium difficile associated diarrhoea, especially in human immunodeficiency virus (HIV) positive patients, and it is important to distinguish between relapse and re-infection in recurrent episodes. The aim of our study was to analyse C. difficile isolates obtained from HIV-positive patients with recurrent diarrhoea in order to distinguish between relapse and re-infection. This analysis was based on the study of DNA similarities among isolates obtained from different episodes within each patient. Relapses occurred in 64% of patients, 32% suffered re-infections and a combination of relapse plus re-infection was seen in 4%. DNA typing methods can be useful tools to characterize recurrent episodes of C. difficile associated disease. Copyright 2001 The Hospital Infection Society.