Clinical condition and comorbidity as determinants for blood culture positivity in patients with skin and soft-tissue infections

Abstract

The utility of performing blood cultures in patients with a suspected skin infection is debated. We investigated the association between blood culture positivity rates and patients’ clinical condition, including acute disease severity and comorbidity. We performed a retrospective study, including patients with cellulitis and wound infection who had been enrolled in three Dutch multicenter studies between 2011 and 2015. Patients’ acute clinical condition was assessed using the Modified Early Warning Score (MEWS; severe: MEWS ≥2) and comorbidity with the Charlson Comorbidity Index (CCI; severe: CCI ≥2). A total of 334 patients with a suspected skin infection were included. Blood cultures were performed in 175 patients (52%), 28 of whom (16%) had a positive blood culture. Data on the clinical condition were collected in 275 patients. Blood cultures were performed in 76% of the patients with a severe acute condition, compared with 48% with a non-severe acute condition (OR 3.5; 95% confidence interval: 2.0–6.2; p < 0.001). Blood cultures were positive in 18% and 12% respectively (OR 1.7 (0.7–4.1); p = 0.3). Blood cultures were performed in 53% of patients with severe comorbidity, compared with 61% without severe comorbidity (OR 0.7; 0.4–1.2; p = 0.2). Blood cultures were positive in 25% and 10% respectively (OR = 3.1; 1.2–7.5; p = 0.02). The blood culture positivity rate among hospitalized patients diagnosed with skin infections was higher than the rates reported by the Infectious Diseases Society of America guidelines, particularly in patients with severe comorbidity. Therefore, the recommendations concerning blood culture performance in patients with a skin infection should be reconsidered.

Antibiotic prescribing practices in the presence of extended-spectrum β-lactamase (ESBL) positive organisms in an adult intensive care unit in South Africa – A pilot study

“…Just under half (47%) of the patients who died also received appropriate treatment after positive ESBL producing organisms, which underlines the fact that sensitivity and microbiology results cannot be interpreted without taking the patients' co-morbidity into consideration. This was also confirmed in a study done by Van Daalen et al 35 Overall, we believe our findings provide a stimulus to establish an antimicrobial stewardship team (ASTs) in this hospital, and likely in other hospitals in South Africa, to reduce inappropriate prescribing and dispensing and reduce AMR rates. 4 Coetzee and Brink underlined the importance of an antibiotic stewardship team and suggest that restrictive measures, even when perceived as punitive measures, may be required to influence future antibiotic prescriptions.…”

Which outcomes are reported in cellulitis trials? Results of a review of outcomes included in cellulitis trials and a patient priority setting survey

“…The use of blood or wound cultures in cellulitis management is debatable. Microbial outcomes are a poor indicator of treatment success as their yield is often low, even in the presence of infection, and they can be adversely affected if patients have been pretreated with antibiotics. Furthermore, microbial cultures do not correlate well with severity of signs and symptoms or patient experience .…”

“…Furthermore, microbial cultures do not correlate well with severity of signs and symptoms or patient experience. 24 This outcome measure is also of limited relevance to patients. However, the increasing incidence of antimicrobial resistance means that other indicators of resistance, such as the incidence and severity of other bacterial infections, may be important to collect.…”

Factors associated with sepsis development in 606 Spanish adult patients with cellulitis

“…Cellulitis can lead to bacteremia and ultimately trigger sepsis development. The frequency of bacteremia in patients with cellulitis ranges from 2 to 21.3% among patients for whom blood cultures were available, depending on the study, setting and typology of the cases analyzed [4][5][6][7][8][9][10][11][12][13][14][15][16]. Taking into account that most cases of cellulitis are treated in the ambulatory setting and that blood cultures are not obtained in many hospitalized patients with less severe cellulitis, populations in which expectedly bacteremia occurs more infrequently, the overall prevalence of positive blood cultures considering the full spectrum of cellulitis would be even lower.…”

“…However, other studies have shown that older age, male sex, diabetes, infected devices, alcohol abuse, cirrhosis, lymphedema and diverse other comorbidities increase the probability of bacteremia and, therefore, the performance of blood cultures in these patients would be advisable [9][10][11][12][13][14][15][16]18].…”