The clinical course of rapidly growing nontuberculous mycobacterial peritoneal dialysis infections in Asians: A case series and literature review.

Introduction: Peritoneal dialysis (PD)-related infections due to rapidly growing nontuberculous mycobacterium (RGNTM) are rare in Asians and have variable clinical outcomes.

Methods: We analysed retrospectively a series of RGNTM infections in a single-centre multi-ethnic Asian population over a 5-year period. Clinical features, treatment, risk factors and outcomes are discussed.

Results: Ten infections are described. They constituted 3% of all culture-positive exit site infection (ESI) and PD peritonitis. Seventy percent were due to Mycobacterium abscessus (three ESI and four peritonitis). There were two Mycobacterim fortuitum and one Mycobacterium chelonei peritonitis. No specific findings differentiated RGNTM infections from those caused by traditional organisms. Six cases had received prior antibiotics, two being topical gentamicin. Initial routine culture and alcohol acid fast bacillus were negative except for one case of M. abscessus. A confirmatory diagnosis was made a median 9 days post culture. No infection responded to routine antibiotics. Antibiotic resistance was variable but M. abscessus was universally sensitive to clarithromycin. Combined antibiotics based on sensitivity profile were successfully used in 70% of the cases. PD catheter loss was 80%. Three-month mortality was 40% (vs. 8.5% and 12% in non-RGNTM ESI and peritonitis, respectively). This may be related to the cohort high mean Charlson score of 7.5.

Conclusion: RGNTM PD infections are commoner in Asians than previously reported. Their early diagnosis requires a high index of suspicion and appropriate treatment started promptly. They are associated with prior antibiotic use and refractory culture-negative infections, delayed diagnosis and lead to significant catheter loss and death.