BACKGROUND: Bacterial contamination of platelet (PLT) concentrates occurs in 1 in 1000 to 1 in 3000 components and has been a leading cause of transfusion-associated morbidity and mortality. Two cases of Pasteurella multocida bacteremia in asymptomatic plateletpheresis donors are reported. Clinical outcomes were profoundly different, emphasizing the importance of robust methods to detect bacterial contamination.

CASE REPORTS: The first case occurred before the implementation of bacterial testing of PLTs. A plateletpheresis component was collected from a 70-year-old man and transfused to an 88-year-old man, who developed rigors, tachycardia, and hypotension within 15 minutes of the start of the transfusion. Cardiopulmonary arrest ensued and he expired 6 hours after transfusion. Blood cultures collected after transfusion and cultures of the PLT component were positive for the presence of P. multocida. Investigation revealed that a feral cat had bitten the donor 100 minutes before his donation. He had not reported the event to the donor room staff. The second case involved a 74-year-old woman who developed a flulike syndrome 2 days after plateletpheresis donation. P. multocida was isolated in routine bacterial culture of her PLT component. The donor had several feral cats, and although there was no history of bite or scratch, one cat liked to lick her hands, which were chapped from gardening.

CONCLUSION: Occult bacteremia with P. multocida transmitted by feral cats was the source of PLT contamination in two cases over 3 years. Bacterial testing of PLTs is critical in the prevention of transfusion-acquired sepsis and allows the identification and treatment of asymptomatic bacteremic donors.