Blood culture contamination in a tertiary care hospital of Saudi Arabia

Abstract

Objectives: To monitor blood culture contamination (BCC) rates in a tertiary care hospital in Saudi Arabia.

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

“…The bacteria of the natural physiological microbiota of patients and staff can be transferred to transport media during venipuncture, and this contamination can be diagnosed as BCC. The most common bacteria isolated from BCC were coagulase-negative staphylococci (CoNS) (84.3%), followed by other skin contaminants; this is in line with the results of similar studies [ 8 , 9 , 13 ]. For example, Weinstein et al isolated a number of organisms representing contamination from adult patients in three hospitals around the USA: CoNS, Corynebacterium species , Bacillus species other than Bacillus anthracis , Propionibacterium acnes , Micrococcus species, viridans group streptococci, enterococci [ 29 , 30 ].…”

“…In clinical practice, false positive cultures are sometimes reported following contamination with human microbiota; these are known as blood culture contaminations (BCCs). However, distinguishing true BSI from contamination remains a challenge for physicians and microbiologists [ 7 , 8 ]. The contamination rate can be calculated in two methods.…”

“…The blood culture contamination rate (%) was calculated according to the following formula: (1) the number of BCC × 100% to the number of total positive BC (true and false positive BC), (2) the number of BCC × 100% to the number of total BC (true positive BC, false positive BC, true negative BC, false negative BC). Despite the development of culture techniques and automation of the identification process, some laboratories report BCC rates of nearly 50% of total positive BC [ 7 , 8 ]. Clinical and Laboratory Standards Institute recommendations indicate that contamination rates for adults in health care settings should not exceed 3%, measured as the total number of blood cultures (total BC) [ 9 , 10 ].…”

“…BCC also results in prolonged hospitalization, i.e., of up to 5 days [ 9 , 10 , 11 , 12 , 13 ]. Studies in the United States estimate the hospital costs associated with BCC to range from USD 2844 to USD 10,078 [ 8 , 13 ].…”

Update Review to Reduce Blood Culture Contamination

“…The duration of cleaning and drying time is important, but this process commonly is insufficient [16]. Also, to reduce commensal microorganism load, the back-and-forth friction method of the area prior to blood drawing is more beneficial than the concentric method [17].…”