Fungal Peritonitis in Continuous Ambulatory Peritoneal Dialysis

Peritonitis causes considerable morbidity in peritoneal dialysis patients, It accounts for most of the catheters lost and is the main reason for transfer to hemodialysis on a temporary or sometimes permanent basis. When severe it requires hospitalization. Oeath may result either from sepsis or from related complications. In the past decade, much progress has been made in reducing the rate of CAPO peritonitis to about one episode every 24 patient months (1); however it still remains a formidable problem. The frequency of bacterial peritonitis has diminished with the introduction of V-systems and other advances in connectology. The impact of these advances has not been felt on fungal peritonitis, which still accounts for 1.5-10% of all peritonitis (2, 3). In the Far East its incidence has been as high as 15% (4). Overall it accounts for 8% of initial no growth peritonitis (5). Some authors believe that the proportional incidence of fungal peritonitis has been stable (6). Though relatively uncommon, fungal peritonitis is important because it causes a disproportionately higher morbidity and mortality; the latter may be as high as 1725% (3, 4, 7). There is a higher incidence of catheter loss and peritoneal adhesions, with resultant transfer to hemodialysis. Several factors predispose to fungal peritonitis. The most consistently correlated is prior antibiotic use (3). The antibiotics are frequently given for bacterial peritonitis and exit site infections, though their use for other infections has also been implicated. Candida species have been isolated in the fecal flora following antimicrobial therapy (8). Transmural migration of intestinal organism after peritoneal irrigation was documented in dogs (9). Conceivably antimicrobial therapy causes alteration of fecal flora, transmigration into the peritoneal cavity and, in the immunocompromised host, growth of fungi. Age, sex, the type of renal disease, and diabetes did not correlate significantly with the development of FP. However, being on immunosuppressive therapy did (3). HIV positive patients (10) also have a high incidence of fungal peritonitis. Intra catheter instillation of streptokinase likewise increases the risk of infection (11). There are reports of fungal peritonitis occurring after fecal peritonitis (2) or infection via the vaginal route (2). Coccidioidal peritonitis has been described in association with pulmonary infections (12), and cryptococcal with meningeal (13); however, the occurrence of PO fungal peritonitis with disseminated fungal infection is uncommon. The mechanism by which fungi, which are normal human commensals and non pathogenic, cause infection remains largely unexplored. A break in the normal barriers by the peritoneal catheter and the presence of peritoneal fluid contribute. Akin to bacterial peritonitis, impaired cellular host defence via impaired polymorphonuclear phagocytosis and intracellular killing plays a role in fungal peritonitis. The fungus colonizes the peritoneal catheter; electron microscopy of removed PO catheters has shown organisms embedded in an amorphous matrix on the surface of the catheters (14), thus rendering successful antifungal therapy difficult. Candida albicans is the commonest cause of fungal peritonitis, causing 75% of all cases (3). Other candida species such as C. guillermondii, C. krusei, C. tropicalis, and C. parapsilosis have also been isolated. An outbreak of fungal peritonitis due to Candida parapsilosis in 12 patients was traced to pigeon droppings obtained from the window-sills of a CAPO unit. Installation of bird-proof netting effectively limited further occurrences (15). Other yeasts that are rarely causal are Coccidioidomycoses immitis (12), Cryptococcus neoformans (13), Rhodotorula rubra (2), and Torulopsis glabrata (16). They probably enter the peritoneal cavity via the peritoneal catheter, intraluminally or peri-Iuminally. Filamentous fungi rarely contaminate the catheter and cause peritoneal infections (8, 17-22). Most infections due to these agents are resistant to antifungal agents, hence catheters are removed early. Other fungi may rarely cause peritonitis. These include Coccidioides immitis (12) Cryptococcus neoformans (13), Rhizopus species (21), Aspergillus species (22), Alternaria (23), Fusarium moniliform (24), Curvularia lunata (25), syncephalastrum (26), Paecilomyces variotii (27), Exophiala jeanselmei (28), and Wangiella dermatidis (29). Curvularia lunata can cause peritonitis as well as isolated catheter obstruction without peritonitis (2). Fungal peritonitis may present with cloudy bags, abdominal pain and fever, features identical to bacterial and sterile peritonitis (30, 35). The white cell count varies from 90 to 10,000 per cubic millimeter, with polymorphs accounting for 2-98% of the cells (3). In 10% of cases