Blood Culture Contamination? Can We Do Better? UNMC Investigates

What are blood cultures?

Blood cultures are a key diagnostic test for persons with sepsis and bacteremia where organisms are grown in the laboratory from patient blood samples to identify the causative agent of infection. Unfortunately, approximately 2-3% of cultures are contaminated, usually with common commensal skin microorganisms. Contaminated blood cultures can “trick” caregivers and result in a significantly longer length of hospital stay and treatment with unnecessary antibiotics. This can result in increased cost, toxicity, and the emergence of antibiotic resistance.

Can rapid blood culture techniques help?

Maybe. The use of molecular-based rapid blood culture systems can more quickly identify microorganisms as probable contaminants and may result in a decrease in the detrimental effects of blood culture contamination. This could include decreased hospital stay and duration of antibiotic treatment.


So, do clinicians use this new technology to result in improved patient outcomes? A recent article authored by Dr. Mark Rupp among other UNMC investigators investigates this question.

Dr. Rupp, co-author of a recent study examining the best way to detect bacteria in patient blood samples.

In a single-center, retrospective, cohort study, they compared hospital length of stay and antibiotic treatment associated with blood culture contamination before and after the introduction of a rapid blood culture identification system (BCID).

They examined the records of 305 patients with blood culture contamination in the pre-BCID and 464 patients with blood culture contamination in the post-BCID periods.

Unfortunately, there was no change in the length of hospital stay (10.8 days versus 11.2 days) and duration of antibiotic treatment (5.1 days versus 5.3 days) in the pre-BCID and post-BCID periods, respectively. Therefore, the authors conclude that the introduction of a rapid BCID system alone does not impact the length of stay and antibiotic treatment associated with blood culture contamination and the use of such systems should be coupled with robust education, antimicrobial stewardship efforts, and real-time decision support.

Read the full article here.

Leave a comment

Your email address will not be published. Required fields are marked *

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

This site uses Akismet to reduce spam. Learn how your comment data is processed.