First report of human Mycobacterium bovis infection in a veterinary laboratory worker in the Republic of Korea.

Objectives: In the Republic of Korea, the previous surveillance system for zoonotic tuberculosis (TB) involved the X-ray testing of humans in contact with Mycobacterium bovis-infected livestock. In contrast, the updated surveillance system incorporates the genotyping of cultured Mycobacterium isolates for high-risk occupational groups. This study aimed to systematically document the detection, diagnosis, assessment, and response in the epidemic investigation of zoonotic TB in a laboratory worker in the Republic of Korea.

Methods: M. bovis was confirmed using spoligotyping and whole genome sequencing. Clinical characteristics were reviewed through epidemiological investigation and interviews with the affected individual. Transmission routes and secondary spread were assessed via field epidemiological investigations and contact evaluations using chest X-ray and interferon gamma release assay for latent TB infection.

Results: A 56-year-old laboratory worker presented with chest X-ray findings compatible with TB and subsequently tested positive for M. bovis. She had no clinical or family history of TB and remained asymptomatic. She completed a 6 month treatment regimen of isoniazid, rifampin, ethambutol, and pyrazinamide without hospitalization. Although no direct transmission pathways for zoonotic TB were identified, her work in a laboratory, processing specimens for zoonotic TB, indicated potential laboratory related exposure.

Conclusion: This case underscores the importance of stringent use of personal protective equipment among high-risk occupational groups and the implementation of an enhanced surveillance system to report zoonotic TB. These findings highlight the need for a One Health approach and proactive surveillance, emphasizing the necessity of refining and strengthening surveillance systems for precise monitoring and an effective response.