Diphtheroid infections of cerebrospinal fluid shunts. The changing pattern of shunt infection in Cleveland.

In the process of trying to decrease infection rates, gentamicin has been used to irrigate shunt systems at the time of surgery. The infection rate did not change, but the epidemiology of infecting organisms changed from Staphylococcus epidermidis to diphtheroids. These indolent and sometimes asymptomatic infections can progress to cause systemic disease with nephritis, peritonitis, or blocked shunts, and are difficult to detect. Laboratory values of cerebrospinal fluid and blood may not be helpful, but prolonged culture incubation on anaerobic media will subsequently yield the organism. Systemic and intraventricular antibiotics may rid the system of diphtheroids and avoid morbidity of shunt revision if the infection is found before systemic disease occurs.