Blood Culture Contamination: A Single General Hospital Experience of 2-Year Retrospective Study.

Anna Tenderenda,Anna Gawron-Skarbek,Robert Dargiewicz,Monika Łysakowska

doi:10.3390/ijerph19053009

Abstract

In the event of blood culture contamination (BCC), blood culture (BC) needs to be repeated. This may delay appropriate treatment, prolong hospitalization and, consequently, increase its costs. The aim of the study was to assess the frequency of BCC and associated factors in a general hospital in Poland based on reports of BC in samples submitted for laboratory testing in 2019–2020. BCC is recognized when bacteria (especially those belonging to natural human microbiota) are isolated from a single sample and no clinical signs indicated infection. True positive BC is confirmed by the growth of bacteria in more than one set of blood samples with the corresponding clinical signs present. The structure of BC sets, microorganisms, and laboratory costs of BCC were analyzed. Out of 2274 total BC cases, 11.5% were true positive BC and 9.5% were BCC. Of all the BCC identified in the entire hospital, 72% was from Internal Medicine (IM) and Intensive Care Unit (ICU) combined. When single sets for BC were used in IM in 2020, the use increased to 85% compared with 2019 (p < 0.05). The predominant isolates were coagulase-negative staphylococci (84%). The estimated extra laboratory costs of BCC exceeded EUR 268,000. The BCC was a more serious problem than expected, including non-recommended using of single BC sets. Compliance with the BC collection procedure should be increased in order to reduce BCC and thus extra hospital costs.

Highlights

One of the key tools available to clinicians for differentiating clinical presentations of bloodstream infections (BSIs) in patients is microbiological diagnosis
Our present paper evaluates the additional laboratory costs caused by contamination in Blood culture (BC) samples; this value is only a component part of the total additional cost associated with blood culture contamination (BCC)
In order to reduce the rate of BCC and lower extra hospital costs, greater adherence to the BC collection procedure should be encouraged, e.g., correct disinfection of skin, and strictly adhering to the rule of using at least two BC sets

Summary

Introduction

One of the key tools available to clinicians for differentiating clinical presentations of bloodstream infections (BSIs) in patients is microbiological diagnosis. Can be used to confirm infectious etiology, isolate etiologic agents, and determine their drug susceptibility, and can form the basis for the implementation of targeted therapy [1–3]. The use of less effective empirical therapy, including broad-spectrum antibiotics, places greater financial burdens on the healthcare provider and can increase drug resistance [4]. Targeting the specific pathogen and employing focused therapy can significantly improve the final outcome [5]. Delayed appropriate treatment may result in prolonged hospitalization, inappropriate antibiotic therapy, and greater exposure to drug side effects and toxicity [4–6]. False positive cultures are sometimes reported following contamination with human microbiota; these are known as blood culture contaminations (BCCs)

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