Relationship of surveillance cultures to bacteremia and fungemia in bone marrow transplant recipients with Hickman or Broviac catheters.

A total of 64 episodes of bacteremia and fungemia were documented in 25 allogeneic bone marrow transplant recipients. Coagulase-negative staphylococci were the most common pathogens recovered, with 34 of the 39 isolated being methicillin resistant. Streptococcus viridans (11 episodes), diphtheroids (5 episodes), and Pseudomonas aeruginosa (4 episodes) accounted for the majority of the other pathogens causing bacteremia. Six episodes of fungemia were also seen. Coagulase-negative staphylococci were demonstrated in 31 of 36 (86%) throat cultures, 25 of 35 (71%) stool cultures, and 6 of 7 (86%) Hickman or Broviac catheter exit site surveillance cultures prior to the development of bacteremia caused by these organisms. Throat surveillance cultures positive for S. viridans also showed a correlation (88%) with subsequent S. viridans bacteremia. However, surveillance cultures for aerobic gram-negative bacilli, diphtheroids, and fungi did not correlate with subsequent septicemia. Organisms isolated in throat surveillance cultures correlated with subsequent bacteremia caused by these organisms in only 15% of all the cultures taken, while only 14% of stool cultures predicted bacteremia. The utility of surveillance cultures is limited because of low cost-effectiveness and a high rate of false-positive results.