Fatal Hormonema dematioides peritonitis in a patient on continuous ambulatory peritoneal dialysis: criteria for organism identification and review of other known fungal etiologic agents

Clinical Features and Risk Factors of Fungal Peritonitis in Children on Peritoneal Dialysis

Objective: To analyse the clinical manifestations, aetiology, prognosis, and risk factors of fungal peritonitis (FP) in children on peritoneal dialysis (PD). Methods: Among 322 children undergoing PD at Children's Hospital of Fudan University, between January 2001 and December 2019, FP cases were retrospectively analysed and compared with those of bacterial peritonitis (BP) to analyse the risk factors of FP. Results: A total of 124 cases of peritonitis were treated, including 11 FP cases in 11 children (0.0019 episodes/patient^*month) and 113 BP cases in 64 children (0.02 episodes/patient^*month). Among the 11 FP cases, 7 cases (63.64%) were caused by Candida and Candida parapsilosis (5/7) was the most common pathogen of Candida. All FP patients were converted to haemodialysis (HD) and did not resume PD during follow-up. Two patients (18.2%) died after 6 months of HD due to heart failure, 2 patients underwent kidney transplant after 2 years of infection, and the other 7 patients were still on HD. The univariate analysis showed the usage rate of antibiotics in the month before the onset of peritonitis was higher (45.45 vs. 15.93%) and the mean serum albumin was lower (31.4 vs. 34.4 g/L) in the FP group when compared with BP group (P < 0.05), while multivariate analysis showed that serum albumin ≤ 30 g/L was an independent risk factor for FP (odds ratio 4.896, 95% confidence interval 1.335-17.961). Conclusion: FP is a rare complication of PD in children, but it is associated with high technique failure. Attention should be paid to hypoproteinaemia and antibiotic use in children on PD.

Fungal Peritonitis in Peritoneal Dialysis Patients

Peritonitis is one of the most frequent complications of peritoneal dialysis (PD) and 1% – 15% of episodes are caused by fungal infections. The mortality rate of fungal peritonitis (FP) varies from 5% to 53%; failure to resume PD occurs in up to 40% of patients. The majority of these FP episodes are caused by Candida species. Candida albicans has historically been reported to be a more common cause than non-albicans Candida species, but in recent reports a shift has been observed and non-albicans Candida may now be more common. Unusual, often “nonpathogenic,” fungi are being increasingly reported as etiologic agents in FP. Clinical features of FP are not different from those of bacterial peritonitis. Phenotypic identification of fungi in clinical microbiology laboratories is often difficult and delayed. New molecular diagnostic techniques ( e.g., polymerase chain reaction) are being developed and evaluated, and may improve diagnosis and so facilitate early treatment of infected patients. Abdominal pain, abdominal pain with fever, and catheter left in situ are risk factors for mortality and technique failure in FP. In programs with high baseline rates of FP, nystatin prophylaxis may be beneficial. Each program must examine its own history of FP to decide whether prophylaxis would be beneficial. Catheter removal is indicated immediately after fungi are identified by Gram stain or culture in all patients with FP. Prolonged treatment with antifungal agents to determine response and attempt clearance is not encouraged. Antifungals should be continued for 10 days to 2 weeks after catheter removal. Attempts at reinsertion should be made only after waiting for 4 – 6 weeks.

Epidemiology, Clinical Manifestations, and Therapy of Infections Caused by Dematiaceous Fungi

The dematiaceous (brown-pigmented) fungi are a large and heterogenous group of moulds that cause a wide range of diseases including phaeohyphomycosis, chromoblastomycosis, and eumycotic mycetoma. Among the more important human pathogens are Alternaria species, Bipolaris species, Cladophialophora bantiana, Curvularia species, Exophiala species, Fonsecaea pedrosoi, Madurella species, Phialophora species, Scedosporium prolificans, Scytalidium dimidiatum, and Wangiella dermatitidis. These organisms are widespread in the environment, being found in soil, wood, and decomposing plant debris. Cutaneous, subcutaneous, and corneal infections with dematiaceous fungi occur worldwide, but are more common in tropical and subtropical climates. Infection results from traumatic implantation. Most cases occur in immunocompetent individuals. Dematiaceous moulds are also important causes of invasive sinusitis and allergic fungal sinusitis. Infection is thought to follow inhalation. Although cerebral infection is the commonest form of systemic phaeohyphomycosis, other localized deep forms of the disease, such as arthritis, and endocarditis, have been reported. Disseminated infection is uncommon, but its incidence is increasing, particularly among immunocompromised individuals. Scedosporium prolificans is the most frequent cause. A number of dematiaceous fungi are neurotropic, including Cladophialophora bantiana, Ramichloridium mackenziei, and Wangiella dermatitidis. Although cases have occurred in immunocompromised persons, cerebral phaeohyphomycosis is most common in immunocompetent individuals with no obvious risk factors. Most forms of disease caused by dematiaceous fungi require both surgical and medical treatment. Itraconazole is currently the most effective antifungal agent for chromoblastomycosis and subcutaneous phaeohyphomycosis, while ketoconazole remains useful for mycetoma. Extensive surgical debridement combined with amphotericin B treatment is recommended for chronic invasive sinusitis. Long-term treatment with itraconazole has led to improvement or remission in some patients that had failed to respond to amphotericin B. Allergic fungal sinusitis requires surgical removal of impacted mucin combined with postoperative oral corticosteroids. Antifungal treatment is not usually of benefit, but post-operative itraconazole may reduce the need for reoperation. The clinical outcome of cerebral and other deep-seated forms of phaeohyphomycosis is dismal, with long-term survival being reported only when complete surgical resection of discrete lesions is possible. The development of new antifungal agents and combination treatment may help to improve the management of these infections.

Melanized fungi in human disease

Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes, including chromoblastomycosis, mycetoma, and phaeohyphomycosis. [corrected]. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. Melanin is a likely virulence factor for these fungi. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Therapy varies depending upon the clinical syndrome. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.

Fungal peritonitis in children on peritoneal dialysis

Fungal peritonitis is a rare but serious complication in children on peritoneal dialysis (PD). In this study, risk factors were evaluated, and therapeutic measures were reviewed. A retrospective, multi-centre study was performed in 159 Dutch paediatric PD patients, between 1980 and 2005 (3,573 months). All peritonitis episodes were reviewed. Fungal peritonitis episodes were evaluated based on possible risk factors and treatment strategy. A total of 321 episodes of peritonitis occurred, with 9 cases of fungal peritonitis (2.9%). Candida peritonitis occurred most frequently (78%). Seven patients (78%) had used antibiotics in the prior month. Fungal peritonitis patients had a higher previous bacterial peritonitis rate compared to the total study population (0.13 versus 0.09 episodes/patient*month), with twice as many gram negative organisms. In all fungal peritonitis patients, the PD catheter was removed. In four patients restart on PD was possible. Fungal peritonitis is a rare complication of PD in children, but is associated with high technique failure. The most important risk factors are a high bacterial peritonitis rate, prior use of antibiotics, and previous bacterial peritonitis with gram negative organisms. The PD catheter should be removed early, but in children, peritoneal lavage with fluconazole before removal may be useful to prevent technique failure.

Fungal peritonitis in patients on continuous ambulatory peritoneal dialysis: a single centre Indian experience

BACKGROUND

Fungal peritonitis (FP) is a serious complication in patients on continuous ambulatory peritoneal dialysis (CAPD). We reviewed our FP cases to analyse the causative agents and possible risk factors in relation to FP and its outcome and mortality.

METHODS

Records of all FP cases were reviewed. FP was diagnosed based on effluent cell count and positive fungal culture in suitable media.

RESULTS

Between October 1993 and November 2001, 261 patients underwent CAPD. FP was detected in 28 patients, one episode in each patient (14.3% of the total peritonitis episodes). Candida species and dematiaceous fungi+/-Candida species were responsible for 89.3 and 10.7% of episodes, respectively. Patients with preceding bacterial peritonitis (BP) developed FP more frequently (25.6%) than de novo cases (2.9%) (P<0.0001) and lower proportion of them continued CAPD (8.6% vs. 60%; P=0.007). Mortality in patients having abdominal pain with and without fever, and catheter in situ was significantly higher than in those patients who did not have these risk factors (9/11 vs. 6/17, P=0.01; 13/17 vs. 2/11, P=0.003; 6/6, vs. 9/22, P=0.01, respectively).

CONCLUSIONS

Higher proportion of our patients had FP; preceding BP was a significant risk factor for development of FP and technique failure. Abdominal pain+/-fever in patients and catheter in situ were identified as risk factors associated with mortality.

Peritonitis due to the dermatiaceous mold Exophiala dermatitidis complicating continuous ambulatory peritoneal dialysis

Exophiala (Wangiella) dermatitidis is a dermatiaceous mold that is an occasional cause of infection in the immunocompromised. We report a case of continuous ambulatory peritoneal dialysis-associated peritonitis probably due to environmental contamination with this organism. Prompt catheter removal and aggressive treatment with amphotericin B allowed an eventual return to peritoneal dialysis.

Early diagnosis of Exophiala CAPD peritonitis by 18S ribosomal RNA gene sequencing and its clinical significance

Phenotypic identification of fungi in clinical microbiology laboratories is often difficult and late, especially for slow growing and rarely encountered fungi. We describe the application of 18S ribosomal RNA (rRNA) gene sequencing in the early diagnosis of a case of Exophiala peritonitis. A yeast-like fungus was isolated from the dialysate fluid of a 66-year-old man undergoing continuous ambulatory peritoneal dialysis. It grew slowly after 12 days of incubation to yield mature cultures to permit recognition of microscopic features resembling those of Exophiala, a dematiacerous mold. 18S rRNA gene sequencing provided results 12 days earlier than phenotypic identification and revealed 15 base difference (0.9%) between the isolate and Exophiala sp. strain GHP 1205 (GenBank Accession no. AJ232954), indicating that the isolate most closely resembles a strain of Exophiala species. The patient responded to 4 weeks of intravenous amphotericin B therapy. Early identification of the fungus was important for the choice of anti-fungal regimen. As opportunistic fungal infections in immunocompromised patients are globally emerging problems, the development of molecular techniques for fungal identification is crucial for early diagnosis and appropriate treatment.

Peritonitis due to Aspergillus and zygomycetes in patients undergoing peritoneal dialysis: report of 2 cases and review of the literature

Fungal peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) has been associated with high mortality and high CAPD-discontinuation rates. Most cases are due to Candida spp. while Aspergillus spp. and zygomycetes have only rarely been implicated. We report one case each of CAPD-related peritonitis caused by Aspergillus terreus and Mucor sp., which have previously been described in the literature once and twice, respectively. The former had a slowly progressive course, did not respond to amphotericin B (AB), and died; the latter improved after a prolonged course of liposomal-AB. Among reported cases of CAPD-related peritonitis due to molds (22 Aspergillus spp. and seven zygomycetes), previous bacterial peritonitis was a common event, the related mortality associated with Aspergillus and zygomycetes was 27% and 57%, respectively, prompt removal of the Tenckoff catheter was critical for survival, and most patients were not able to resume CAPD.