Mycobacterial Peritonitis in CAPD Patients in Limpopo: A 6-Year Cumulative Report from a Single Center in South Africa

Abstract

South Africa has one of the highest incidences of tuberculosis (TB) worldwide due to the ongoing human immunodeficiency virus (HIV) epidemic. There are, however, no reports on peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients due to Mycobacterium tuberculosis in South Africa. The aim of this study is to discuss our experience of tuberculous peritonitis in CAPD patients from a rural endemic area of South Africa. This is a retrospective descriptive study of CAPD patients diagnosed with mycobacterium peritonitis infection from January 2008 to August 2014 at the Limpopo Kidney and Dialysis Centre (LKDC) in South Africa. The diagnosis of peritonitis was based on the International Society for Peritoneal Dialysis (ISPD) 2010 recommendations. Peritoneal fluid samples were collected in BACTEC Myco/F Lytic Culture Vials (Becton, Dickinson and Company, Dublin, Ireland). Tenckhoff catheter tips were sent for acid-fast bacilli (AFB) smear and TB culture. Mycobacterium infection was considered in patients with clinical features of peritonitis if 1) AFB smear or TB culture was positive or 2) if the patient was smear- or culture-negative but had suggestive radiological features of TB in the lungs or abdomen or 3) if the patient improved clinically following treatment with anti-tuberculous drugs. Of 170 patients on CAPD for the period reviewed, 12 (7.1%) were diagnosed and treated for mycobacterial peritonitis. There was an equal number of males and females, and all the patients were Black Africans with a mean age of 35.4 years (17 – 51 years). Eight of the 12 patients (66.7%) had had previous episodes of non-tuberculous peritonitis. Four patients (33.3%) had elevated white blood cell count (WCC) while 9 had higher polymorph count in the PD fluid than lymphocyte count. Mycobacterial organism was confirmed in 9/12 (75%), while the diagnosis was made on clinical and radiological features in the remaining 3 patients. Seven patients (58.3%) died, 10 patients were permanently transferred to hemodialysis (HD), 1 patient returned to PD after a short stay on HD, 1 patient died after 2 years on HD due to lack of further access to dialysis, and in 1 patient, the catheter could not be removed before death. This case series corroborates findings from other previous series that mycobacterial infection in PD patients carries a high mortality and can often pose a diagnostic challenge to attending clinicians. Clinicians should have a high index of suspicion for mycobacterial peritonitis in CAPD patients with features of peritonitis who do not respond promptly to conventional anti-microbial agents. We feel that the recommendation about catheter removal during mycobacterial peritonitis should be revisited, as it had no impact on our patients' outcome.