Differing prognostic significance of reinfection and relapse in CAPD peritonitis.

All episodes of recurrent infection in a CAPD unit over a 26-month period have been analysed to discover whether relapse and reinfection have different prognostic importance. Relapse and reinfection were distinguished by detailed microbiological investigation. Prognosis was expressed in terms of outcome of treatment and the fate of the Tenckhoff catheter. Twenty-nine patients suffered recurrent infections (i.e. more than one infection during a 12-month period). Nine (6 male, 3 female, age range 42-73 years) had relapses, and 20 (16 male, 4 female, age range 42-74 years) reinfections. The characteristics of the two groups of patients were indistinguishable. Relapse was of graver prognostic consequence: patients who relapsed were significantly less likely to respond to antibiotic treatment (78% versus 20%) and have to have their catheters removed (78% versus 10%) than those with reinfections. Thus it is important to differentiate relapse from reinfection in CAPD peritonitis. In addition to being helpful for the management of individual patients, this is essential if results of therapeutic trials are to be interpreted correctly.