Biosafety Practices in Mycobacteriology Laboratory

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is classified as a risk group 3 agent, which calls for a Biosafety Level 3 laboratory (BSL-3) for culture, drug susceptibility testing, and other laboratory examinations. Access to a safety laboratory should be restricted to staff members and accredited visitors. M. tuberculosis can cause laboratory-acquired infections. To ensure adequate infection control, it is crucial that a comprehensive and strict biosafety policy is developed and followed. Such a policy includes standardized rules and regulations for containment, personal protective equipment (PPE), standard operating procedures (SOP) for different laboratory tasks, and a transparent structure for regulating safe working conditions in diagnostic TB laboratories. It is well documented that M. tuberculosis can cause laboratory-acquired infections, and the risk of TB among healthcare workers is consistently higher than in the general population. M. tuberculosis even features in the top-ten list of hazardous agents for laboratory staff. However, the source of the TB infection can only be traced to a specific laboratory accident in a minority of cases. The most important route for laboratory-acquired infections is aerosols. Thus, infection control efforts need to focus on limiting the generation of aerosols during laboratory work, for example, through safe centrifugation and pipetting. For effective infection control, it is crucial that a comprehensive and strict biosafety policy is developed, accepted, and followed by the laboratory staff. The policy should include standardized rules and regulations for containment; personal protective equipment (PPE); practical training; standard operating procedures (SOPs) for all the different laboratory tasks, and transparent and clearly defined levels of responsibility for establishing and maintaining safe working conditions in the diagnostic TB laboratory.