A rare case of gastrointestinal mucomycosis following Plasmodium knowlesi infection

Abstract

Background: A 59 years non-diabetic, known hepatitis B, HIV-negative male presented with tiredness, unwell, loss of appetite and coffee ground vomitus. He had tachycardia, central cyanosis with 64% SPO2 on 8 litre of oxygen. With laboratory investigations, revealing thromocytopenia, leucocytosis, impaired renal chemistry and blood gas analysis, diagnosis of sepsis with metabolic acidosis was made and was admitted to ICU, suspecting melioidosis starting on co-amoxyclav and ceftazidime continued for 12 days. Results: Septic screen and blood cultures done reported negative, but following day, blood picture revealed Plasmodium knowlesi infection. Quinine IV and doxycycline were started and continued for 7 days. Severity of plasmodium infection led to renal shutdown warranting sustained low-efficiency dialysis from day two. On day 12, severe bleeding per rectum was noticed. Colonoscopy revealed altered blood in lumen, irregular edged circumferential ulcer in sigmoid and superficial ulcer in proximal ascending colon. Biopsy from sigmoid ulcer edge showed branching, broad, aseptate, invasive fungal filaments, identified as mucormycosis based on morphology as culture was not done. Patient was commenced on amphotericin B. Conclusion: Mucormycosis an opportunistic fungal infec-tion caused by mucoromycotina is in the order mucorales. Invasive gastrointestinal mucor-mycosis, with commonest site being stomach followed by colon, is an extremely rare condition associated with diabetes mellitus, corticosteroid treatment, malnutrition, and immunosupression following solid organ transplant. This acute, rapidly fatal condition with overall mortality rate of 50–80% is often diagnosed at post-mortem. Gastrointestinal mucor-mycosis rare in Brunei with one fatal case reported in 2011 by one of the authors. In this case high degree of clinical suspicion, early diagnosis by colonoscopy, biopsy and histopathology, permitted timely commencement of amphotericin B monotherapy with supportive treatment. Patient's clinical condition improved and repeat colonoscopy done 3 weeks later revealed regression of the ulcers found previously. Predisposing factor in this previously healthy immunocompetent adult with no known predisposing risk factors could be attributed to immunosupression following Plasmodium knowlesi infection with or without subsequent renal impairment. Contribution of past hepatitis B infection towards this fungal infection is not known. Hence clinical suspicion, early detection, timely appropriate treatment can reduce high fatality associated with this infection without need for surgery.