An outbreak of infections with Acinetobacter calcoaceticus in burn patients: contamination of patients' mattresses.

During a 21-month period Acinetobacter calcoaceticus was the most common organism causing infections in a university burn center. Forty-three of 103 patients admitted became infected with this organism. Risk factors associated with burn wound colonization with Acinetobacter included larger burns and Foley catheter use; however, only a longer duration of hospitalization was an independent discriminator of colonization. Infection-control measures, including strict isolation and closure and repainting of the burn unit, did not prevent the transmission of Acinetobacter. An investigation found that wet mattresses served as environmental reservoirs of Acinetobacter. This finding led to a policy of discarding each patient's mattress on the day of the patient's discharge from the burn unit. Life table analysis demonstrated that this intervention led to a reduced risk of burn wound colonization with Acinetobacter (P less than .05) and ultimately resulted in the complete elimination of the organism from the burn unit.