Contamination of operative wounds during surgery occurs primarily
through contact and secondarily through the airborne route. Inspection and
maintenance of air-handling equipment is essential, with special reference
to air intakes, filters, humidifiers, and exhaust systems. Doors should
remain closed to maintain positive pressure. Surgical attire for all
personnel must provide for complete coverage of hair and arms. Intensive
interim cleaning of all horizontal sufaces between operations is essential.
The infection rate is proportional to the duration of the operation and the
number of personnel in the room, and inversely proportional to the air
changes per hour.