Bacterial Proliferation in Platelet Products Stored at Room Temperature

Abstract
A theoretical objection to ambient-temperature platelet storage is the possibility of proliferation of micro-organisms introduced into the system during phlebotomy or component preparation. After gram-negative septicemia followed platelet infusion in two patients with cancer, a study was begun to determine the frequency of contamination in platelets stored at 25°C. Culture of 2188 U of platelets, pooled in groups of eight after storage, revealed bacteria in more than 20 per cent of pools; the minimal frequency of contamination in individual units was calculated to be 2.4 per cent. Bacteria including species of corynebacterium, staphylococcus, micrococcus, streptococcus, sarcina, bacillus, herellea, pseudomonas and flavobacterium were recovered; Enterobacter (Aerobacter) cloacae was isolated seven times and caused both septicemias. Twenty-five of 143 transfusions were later shown to have contained micro-organisms. The frequency of bacterial recovery progressively increased with increasing storage time. Such platelets should be used with caution, particularly in patients lacking normal host-defense mechanisms.