Interpretation of the results of blood culture and interventional role by clinical laboratory physicians

Blood culture has long been recognized as the gold standard for the definitive diagnosis of bacterial and fungal infections. However, fewer blood cultures have been tested and their results have not been fully used in Japan. Clinical laboratory physicians should play an interventional role, such as recommending blood culture tests in patients with infectious disease or fever of unknown origin. In our hospital, clinical laboratory physicians act as on-call consultants. The yearly number of consultations is between 500 and 700, and consultations concerning infectious disease have increased up to 40% in the past 5 years. As a result, the number of blood cultures and the percentage of 2-set blood collections have increased in order to increase the positivity rate and determine whether the results obtained were contaminated. However, physicians sometimes misunderstand the results of blood culture, and they assume that the identified organism was causative, or that sepsis did not exist if the culture is negative. Clinical laboratory physicians should act as consultants more frequently, concerning the interpretation of blood culture results, and the choice of antimicrobial agents, because the inappropriate use of antimicrobial agents leads to higher mortality and higher medical costs. Finally, collaboration between clinical laboratory physicians and co-medical staff such as the infection control team, nurses and pharmacists is necessary.