Bacteriological evaluation of a down-draught necropsy table ventilation system.

AIMS To evaluate the microbiological efficacy of a down-draught necropsy table ventilation system (which surrounds the cadaver with a "curtain" of air under continuous extraction) during post mortem procedures. METHODS Air sampling was carried out both in the presence and absence of staff and cadaver and during a full post mortem procedure, with functioning and non-functioning table air extraction. The penetration of the air "curtain" was also examined during the use of an oscillating bone saw by means of a tracer organism, Bacillus subtilis var niger, painted on to the skull. RESULTS There was little difference between bacterial counts obtained in the presence of staff only, staff plus cadaver, or during a post mortem examination. With all counts obtained, however, there was a two to three-fold reduction when the ventilation was in operation compared with when the extract duct was occluded. Using the tracer organism, a two to three log reduction in counts was shown when the "curtain" was in operation during the use of the oscillating bone saw. CONCLUSIONS These results suggest that the system provides potential protection for post mortem room staff against airborne infections.