Disseminated Talaromyces marneffei infection mimicking intestinal tuberculosis

A 27-year-old immunocompetent man presented to our hospital with fever (maximum 38·7°C), coughing with sputum, diarrhoea, right lower abdominal pain, and weight loss of 6 kg over 3 months. He had repeatedly caught and eaten wild Rhizomys pruinosus (hoary bamboo rat) in the 4 months before admission. His medical history was unremarkable, except that he had not ever been vaccinated with the BCG vaccine. Laboratory examinations revealed that his white blood cell count was 7·25 × 109/L, procalcitonin count was lower than 0·05 ng/mL, erythrocyte sedimentation rate was 46 mm/h, and hypersensitive C-reactive protein count was 17·25 mg/L. CT imaging showed a shadow of a mass in the apicoposterior segment of the left lung's superior lobe (figure A). Colonoscopy revealed multiple annular ulcers in the ileocoecal region and a biopsy was done (figure B). An initial diagnosis of intestinal Mycobacterium tuberculosis infection was considered; however, subsequent sputum smears failed to find acid-fast bacilli and a tuberculin skin test and an interferon-γ release assay were negative. Periodic-acid-Schiff staining of intestinal biopsy specimens showed central septation of yeasts. Cultures at 25°C and 37°C on Sabouraud dextrose agar of blood, sputum, and intestinal biopsy specimens showed the presence of Talaromyces marneffei. The patient had no cell-mediated immune impairment, including HIV infection, malignancy, rheumatic disease, or immunosuppressive therapy. The patient consequently received antifungal therapy of intravenous voriconazole (200 mg twice daily) and intravenous liposomal amphotericin B (30 mg; 0·5 mg/kg bodyweight once daily) for 14 days, followed by oral voriconazole (200 mg twice daily) for 9 months. The response assessment by CT and colonoscopy at 12 months after admission showed morphological resolution of the lung and ileocoecal region. No relapse of talaromycosis was observed 13 months after ending the antifungal treatment.