Candida tropicalis native-valve endocarditis initially presenting as persistent Candida orthopsilosis fungemia after short-term TP in a stage IIB colon cancer patient: A case report

Background/Rationale: Fungal infective endocarditis (IE) is a rare debilitating opportunistic infection with high mortality and difficulty in diagnosing1. It frequently affects prosthetic valves2 and is associated with long-term total parenteral nutrition (TPN)3. This case is an immunocompromised elderly who developed persistent candidemia after short-term TPN and eventually fungal IE despite multiple antifungal medications.

Case Proper: A 67-year-old male with pre-operative mitral regurgitation was admitted for hemicolectomy for Stage IIB colon cancer. He was placed on TPN and developed a fever three days after. Patient was given Piperacillin-Tazobactam but was shifted to Micafungin after positive blood culture (BC) to Candida spp. TPN was discontinued but fever persisted. Repeat BC revealed Candida orthopsilosis.

Patient was discharged with Fluconazole. Repeat BC every two weeks showed persistent candidemia. One month post-hemicolectomy, the patient was readmitted for myocardial infarction. He was febrile with no cardiac murmurs. Other PE findings were unremarkable. Patient underwent a coronary angiogram revealing a thrombus leading to angioplasty. Fever and candidemia persisted post-angioplasty. Transesophageal echocardiography confirmed the presence of vegetation on the mitral valve indicative of valvular replacement.
Prior to cardiothoracic surgery, Amphotericin B was started for suspected fungal brain abscess after focal seizures. Mitral valve tissue culture revealed a different species, Candida tropicalis. Patient was discharged with Fluconazole after a repeat BC showing eradication of candidemia after successful mitral valve replacement surgery.

Discussion: Previous studies showed consistent association between candidemia and TPN4,5,6. This is higher among elderly, shortening Candida growth time3. These factors along with pre-existing mitral regurgitation and malignancy contributed to developing fungal IE1. A retrospective study showed that abdominal surgery increases the risk of candidemia7 possibly contributing to the isolation of different species - Candida tropicalis from mitral valve tissue in contrast to the initial Candida orthopsilosis from the blood before hemicolectomy.

Conclusion: Suspicion of fungal IE should always be considered in the setting of persistent candidemia. Repeat 2D echocardiography along with blood culture is recommended for earlier diagnosis of fungal IE to prevent embolic events especially among high risk.