Operational Handbooks

A code of practice describes the laboratory practices and procedures essential for implementing good (that is, safe) microbiological technique. The laboratory manager should use the code of practice to develop written descriptions of procedures that should be followed to perform work safely. This safety or operations manual should also identify known and potential hazards, and specify practices and procedures to minimize the risks associated with such hazards.

All TB laboratories, regardless of the procedures being undertaken, should enact a set of essential biosafety measures to minimize risks. These measures affect:

1. codes of practice

2. equipment

3. laboratory design and facilities

4. health surveillance

5. training

6. waste handling.

Employee occupational health programmes should promote a safe and healthy workplace. This is accomplished by minimizing any exposures, promptly detecting and treating exposures, and using information gained from laboratory incidents and accidents to enhance safety precautions. A baseline medical checkup and provision for regular follow-up should be considered for all staff prior to commencing work in the TB laboratory.

The laboratory manager should conduct regular audits to monitor risks and control measures. These can be done by reviewing reports of corrective actions taken after problems were identified earlier, thoroughly investigating incidents or accidents and implementing preventive measures, and ensuring that adequate resources are provided to maintain the necessary level of precautions. Documenting the risk assessment process and identifying mitigation measures are integral and important steps to ensure that biosafety measures selected and implemented are constantly improved.

A hazard is anything that has the potential to cause harm, regardless of how likely or unlikely it might be to occur. A hazard may be a physical situation (such as a fi re or explosion), an activity (such as pipetting) or a material (such as aerosols containing infectious bacilli). Unless hazards are identified effectively, it is not possible to accurately assess the risks associated with the facility and its activities.

Laboratory biosafety is the process of applying a combination of administrative controls, containment principles, practices and procedures, safety equipment, emergency preparedness, and facilities to enable laboratory staff to work safely with potentially infectious microorganisms; biosafety also aims at preventing unintentional exposure to pathogens or their accidental release. This manual describes the minimum biosafety measures that should be implemented at the different levels of tuberculosis (TB) testing laboratories to reduce the risk of a laboratory-acquired infection.

The following contributed to the writing of this manual:

Christopher Gilpin (Lead), Jean Iragena, Fuad Mirzayev, Wayne van Gemert, Karin Weyer

The following participated in the joint CDC–WHO International Technical Consultation on Laboratory Biosafety, 2–4 September 2008, Atlanta, GA, USA:

May Chu, Daniela Cirillo, Philippe Dubois, Christopher Gilpin, Paul Jensen, Shanna Nesby, Nicoletta Previsani, John Ridderhof, Thomas M Shinnick, Veronique Vincent, Karin Weyer.

Following a technical consultation held between the World Health Organization (WHO) and the United States Centers for Disease Control and Prevention (CDC) in Atlanta, GA, in September 2008 on strategies, approaches and partnerships that could be implemented to improve laboratory biosafety worldwide, an Expert Group meeting was convened at WHO’s Headquarters in Geneva, Switzerland, in April 2009 to elaborate guidance on biosafety related to laboratory procedures for diagnosing tuberculosis (TB). Members of the Expert Group submitted Declarations of Interest.

Environmental controls are the second pillar of the triad of IPC measures and should be implemented in combination with other TB IPC measures. The aim is to reduce the concentration of infectious particles in the air through a mix of interventions for dilution, removal, filtration or disinfection.