Back
Nocardia species is commonly found in soil and water, and a cause of opportunistic infections. Transmission to humans is usually via inhalation or skin inoculation. It is rarely described as a cause of peritoneal dialysis-related peritonitis, secondary to systemic dissemination. We report a case of Nocardia peritoneal dialysis-related peritonitis in a 47-year-old female from South Africa, with autosomal dominant polycystic kidney disease (ADPKD), from direct inoculation via her Tenckhoff catheter. Summarizing the clinical characteristics, treatment course and outcome.
Our patient was diagnosed with ADPKD complicated by hypertension and chronic kidney disease in 2012. She progressed to end stage kidney disease in 2018 and was initiated on automated PD (APD). Her script was bicarbonate and dextrose based APD; five 2 litre (1.5% dextrose), 2-hour exchanges per night. She had no previous episodes of peritonitis. She had a background history of hypothyroidism. She was a keen and frequent bird watcher, at times lying prone in outdoor environments.
On admission she complained of a 2-day history of fatigue, loss of appetite, abdominal cramps, and fever. She was hemodynamically stable but had generalised abdominal tenderness. Turbid peritoneal fluid was sent off for microscopy and culture.
Her peritoneal fluid revealed 11742 white cells/uL of which 89.6% were polymorphs. The Gram stain and acid-fast bacilli stains were both negative. After 5 days of incubation of the inoculated agar plates, Nocardia species was identified using MALDI-TOF mass spectrometry and confirmed on 16S rRNA PCR and sequence analysis. (Figure 1) A contrasted CT scan revealed no intracranial or intrathoracic evidence of Nocardia infection, suggesting direct transmission via the Tenckhoff catheter.
The patient’s laboratory parameters throughout the course of her treatment are shown in Table 1. She was initially treated empirically with a stat dose of intraperitoneal (IP) vancomycin and gentamicin on admission as per local guidelines. Once the Nocardia spp. was identified antibiotics were changed to amikacin IP and oral high dose trimethoprim-sulfamethoxazole (TMP-SMX), guided by broth microdilution susceptibility testing.
This is the first description of Nocardia spp. peritonitis in Africa. Our patient had an unusual route of transmission for Nocardia infection via her Tenckhoff catheter directly into her abdominal cavity, most likely related her birding. She remained on APD and underwent the majority of her treatment as an outpatient on prolonged oral medication, with a favourable outcome. This case report highlights the importance of extended culture of peritoneal dialysis fluid in patients with suspected peritonitis.