Biosafety level 3 laboratory for autopsies of patients with severe acute respiratory syndrome: principles, practices, and prospects.

BACKGROUND

During the outbreak of the emergent severe acute respiratory syndrome (SARS) infection, >30% of the approximately 8000 infected persons were health care workers. The highly infectious nature of SARS coronavirus (SARS-CoV) compelled our pathologists to consider biosafety issues in the autopsy room and for tissue processing procedures.

METHODS

A specially designed biosafety level 3 (BSL-3) autopsy laboratory was constructed and divided into a clean area, a semicontaminated area, a contaminated area, and 2 buffer zones. High-efficiency particulate air filters were placed in the air supply and exhaust systems. Laminar air flow was from the clean areas to the less clean areas. The negative pressures of the contaminated, semicontaminated, and clean areas were approximately -50 pa, -25 pa, and -5 pa, respectively. Personal protective equipment, including gas mask, impermeable protective clothing, and 3 layers of gloves worn during autopsies; the equipment was decontaminated before it was allowed to exit the facility. Strict BSL-3 practices were followed.

RESULTS

When a given concentration of particulate sarin simulant was introduced into the contaminated area, it could not be detected in either the semicontaminated area or clean area, and particles >0.3 microm in size were not detected in the exhaust air. A total of 16 complete postmortem examinations for probable and suspected SARS were performed during a 2-month period. Of these, 7 reported confirmed cases of SARS. None of the 23 pathologists and technicians who participated in these autopsies was infected with SARS-CoV.

CONCLUSIONS

Our experience suggests that BSL-3 laboratory operating principles should be among the special requirements for performing autopsies of contaminated bodies and that they can safeguard the clinicians and the environment involved in these procedures.