Abstract: A 65-year-old male presented with swollen right thumb for more than 1 month, 10 days after incision and drainage of abscess. The incision did not heal when visited the doctor, so histopathology and bacteria culture of the tissue were not performed. The patient was tested positive for T-SPOT.TB. The tuberculosis was not considered by chest radiograph and PPD test and the patient had a suspicious history of hairtail fish stabbing. Based on the patient's history and positive result of T-SPOT.TB the diagnosis of Mycobacterium murinum infection were highly suspected. After 3 weeks, the incision was healed and histological examination showed inflammatory granuloma and the tissue qPCR was positive for Mycobacterium murinum. The final diagnosis was Mycobacterium murinum infection. The patient was treated with oral clarithromycin and recovered after 3.5 months.

Key words: T-SPOT.TB, Mycobacterium murinum infection