More than Skin Deep: Primary Inoculation with Mycobacterium tuberculosis as an Occupational Hazard

Background: Sharps injuries pose a significant occupational risk for healthcare and laboratory workers, with hundreds of thousands of incidents reported annually. While protocols for blood-borne pathogens like HIV and hepatitis viruses are well-established, the risk of traumatic inoculation with Mycobacterium tuberculosis ( M. tuberculosis ) is under-recognized. Methods: This case series reviews six separate instances of healthcare and laboratory personnel across multiple academic health systems in a northeastern U.S. metropolitan region who developed cutaneous tuberculosis following sharps injuries in environments where M. tuberculosis was present. This series was used to identify gaps in current sharps safety guidelines and to propose improved and standardized safety protocols. Results: All patients were previously nonsensitized to M. tuberculosis and presented with tuberculous chancre at the inoculation site. Diagnosis was delayed in several cases, resulting in prolonged morbidity and unnecessary exposure to ineffective treatments. Treatment regimens varied considerably across the cases, reflecting a lack of standardized guidelines for managing this rare form of the disease. Furthermore, no established post-exposure prophylaxis (PEP) protocols for M. tuberculosis exist for direct inoculation, in stark contrast to guidelines for airborne TB exposure. Conclusion: This review highlights critical gaps in occupational health and biosafety policy. We conclude that awareness of primary cutaneous tuberculosis as a potential sequela of sharps injuries is essential for early diagnosis and effective management. These findings support the development of standardized diagnostic algorithms and evidence-based PEP recommendations to better protect workers from this preventable hazard.