Evaluation of the buffy-coat smear for rapid detection of bacteremia

Buffy-coat smears prepared from 599 blood samples, obtained simultaneously with blood for culture, were examined for bacteria. Each blood sample was quantitatively cultured on chocolate agar. Twenty-one blood cultures (3.6%) from 17 patients were positive. Two (11.7%) of the 17 patients had positive buffy-coat smears. One patient had two positive smears, for a total of three positive buffy-coat smears from 21 positive blood cultures. Chart reviews were performed for two patients with positive buffy-coat smears, three patients with positive blood cultures (containing the same organisms as the two study patients) but negative buffy-coat smears, and six additional patients who had had positive buffy-coat smears between 1974 and 1979. Of the eight patients with positive smears, six (75%) were infected with Gram-positive cocci, three of which were Streptococcus pneumoniae. Mortality was 100%.