Prevention

A spill of infectious material outside a BSC is considered a major event. Spills of infectious liquid will generate infectious aerosols. Everyone should immediately vacate the affected laboratory area. The laboratory manager should be informed of the incident immediately, and staff must be prevented from re-entering the laboratory for at least 1 hour to allow aerosols to be removed through the laboratory’s ventilation system and allow time for heavier particles to settle.

The plan should provide operational procedures for:

A written emergency preparedness plan for dealing with laboratory incidents and accidents is a necessity in any facility that works with or stores M. tuberculosis isolates.

Laboratory staff should be trained to remove their gloves by following these steps:

1. peel one glove off by grasping it under the cuff and rolling the glove off the hand so that it comes off inside out. This keeps most of the contamination inside;

2. hold the used glove in the opposite still-gloved hand. Carefully slip exposed fingers under the cuff of the gloved hand, being careful not to touch the surface of the contaminated glove. Peel the glove off, inside out, rolling it over the other used glove to form a bag of used gloves with contamination inside.

Gloves must be worn for all procedures that involve direct contact, or may involve accidental contact, with sputum, blood, body fluids and other potentially infectious materials. After use, gloves should be removed aseptically and hands washed.

Contaminated gloves (and unwashed hands) may be a source of infection for other staff members if they are used to handle or operate equipment in the laboratory (such as a centrifuge or telephone).

• Staff should remove their gloves and thoroughly wash their hands before removing respirators. Only the straps should be handled; staff should avoid touching the front of the respirator.

Staff who use respirators must be trained. They should be taught to:

Respirators are not normally required for work in a TB laboratory. However, they may be recommended after a risk assessment if cultures are being manipulated within a TB-containment laboratory. Even if not worn regularly, respirators must be available in laboratories where culture manipulations are performed in case an accidental biohazard (such as a spill) occurs outside the BSC. Respirators should be included as part of a laboratory’s spill clean-up kit.

Respirators should never be used as a substitute for a properly maintained and functioning BSC.

Laboratory gowns should have long sleeves and open in the back. When the laboratory technician is standing, the gown must extend below the height of the workbench; the gown should fully cover the technician’s lap when he or she is sitting. Reusable gowns should be autoclaved before being washed. Gowns must not be taken home for washing; laundering services should be provided at or near the facility. Laboratory gowns should be changed at least once a week and immediately after being overtly contaminated.