scholarly journals 1076. What Is the Positivity Delay of Blood Cultures in Infective Endocarditis?

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S322-S322
Author(s):  
Nahema Issa ◽  
Olivia Peuchant ◽  
Raphael Lecomte ◽  
Irene Machelart ◽  
Carine Greib ◽  
...  

Abstract Background Blood culture is a key test for the positive diagnosis of infective endocarditis (IE). In order to detect certain so-called fastidious bacteria and to avoid the absence of documentation, it is customary to repeat the blood cultures (at least three series) and to keep them for 21 days. However, objective data regarding the positivity delay of blood cultures in case of infective endocarditis are lacking. Methods To determine the time to positivity of blood cultures during IE, all patients with documented IE by bacterial blood culture and presented to the Endocarditis team of our center were prospectively included. The study was conducted in a university hospital between 2013 and 2017. Results During the study, 441 patients with IE were hospitalized and 401 IE had a bacteriological documentation (91%), including 380 by blood cultures. In 21 cases, the bacteriological documentation was made by serological tests or specific PCR assays. Information on positivity delay was available for 237 patients (135 IE on native valve and 102 on prosthetic valve) and 183 of them (77%) had 4 aero-anaerobic series or more blood cultures. Of the 988 series sampled, 978 (99%) were positive. The main documented bacteria were staphylococci (41%), streptococci (32%), and enterococci (21%). The median time to positivity of the first blood culture was 11.4 hours [interquartile = 7.3 hours–16.7 hours] and the maximum delay was 93 hours. There was no difference in positivity delay between the 123 community acquired IE and the 114 healthcare-associated IE: 11.2 hours vs. 11.4 hours. The median growth time was 9.9 hours for S. aureus vs. 18 hours for coagulase negative staphylococci, 11 hours for enterococci and 10.4 hours for streptococci. In the case of IE complicated by extracardiac emboli, the median positivity delay was 9.7 hours in the case of S. aureus vs. 12.3 hours for the other bacteria. Conclusion In case of IE, our study shows that the median time positivity of the first blood culture is about 11 hours and no blood culture becomes positive beyond the fourth day. Slow-growing bacteria are identified by other diagnostic methods. We can, therefore, wonder about the need to multiply and conserve blood cultures beyond a week to document IE. Disclosures All authors: No reported disclosures.

2021 ◽  
Vol 10 (24) ◽  
pp. 5824
Author(s):  
Vincent Fihman ◽  
Hélène Faury ◽  
Amina Moussafeur ◽  
Raphaelle Huguet ◽  
Adrien Galy ◽  
...  

To assess the need for prolonged incubation of blood culture bottles beyond five days for the diagnosis of infectious endocarditis (IE), we conducted a retrospective cohort study of 6109 sets of two blood culture bottles involving 1211 patients admitted to the Henri Mondor University Hospital for suspicion of IE between 1 January 2016 and 31 December 2019. Among the 322 patients with IE, 194 had positive blood cultures in our centre. Only one patient with a time-to-positivity blood culture of more than 120 h (5 days) was found. The main cause for the 22 patients with positive blood cultures after five days was contamination with Cutibacterium acnes. Our results do not support extending the duration of incubation of blood culture bottles beyond five days for the diagnosis of infectious endocarditis, with the exception of patients with risk factors for C. acnes infection.


Author(s):  
David Krus ◽  
Fredrik Kahn ◽  
Bo Nilson ◽  
Torgny Sunnerhagen ◽  
Magnus Rasmussen

AbstractNon-β-hemolytic streptococci (NBHS) cause infective endocarditis (IE) and a short blood culture time to positivity (TTP) is associated with risk of IE in bacteremia with other pathogens. In this retrospective population-based cohort study, we investigate if TTP is associated to IE or mortality. Of 263 episodes with NBHS bacteremia, 28 represented IE and the median TTP did not differ significantly between episodes with IE (15 h) and non-IE (15 h) (p=0.51). TTP was similar among those who survived and those who died within 30 days. However, TTP significantly differed when comparing the different streptococcal groups (p<0.001).


Author(s):  
Katryn Paquette ◽  
David Sweet ◽  
Robert Stenstrom ◽  
Sarah N Stabler ◽  
Alexander Lawandi ◽  
...  

Abstract Background Sepsis is a leading cause of morbidity, mortality, and health care costs worldwide. Methods We conducted a multi-center, prospective cohort study evaluating the yield of blood cultures drawn before and after empiric antimicrobial administration among adults presenting to the emergency department with severe manifestations of sepsis (ClinicalTrials.gov: NCT01867905). Enrolled patients who had the requisite blood cultures drawn were followed for 90 days. We explored the independent association between blood culture positivity and its time to positivity in relation to 90-day mortality. Findings 325 participants were enrolled; 90-day mortality among the 315 subjects followed-up was 25·4% (80/315). Mortality was associated with age (mean age in those who died was 72·5 ±15·8 vs. 62·9 ±17·7 years among survivors, p&lt;0·0001), greater Charlson Comorbidity Index (2 (IQR 1,3) vs. 1 (IQR 0,3), p=0·008), dementia (13/80 (16·2%) vs. 18/235 (7·7%), p=0·03), cancer (27/80 (33·8%) vs. 47/235 (20·0%), p=0·015), positive qSOFA score (57/80 (71·2%) vs. 129/235 (54·9%), p=0·009), and normal white blood cell counts (25/80 (31·2%) vs. 42/235 (17·9%), p=0·02). The presence of bacteremia, persistent bacteremia after antimicrobial infusion, and shorter time to blood culture positivity were not associated with mortality. Neither the source of infection nor pathogen affected mortality. Interpretation Although severe sepsis is an inflammatory condition triggered by infection, its 90-day survival is not influenced by blood culture positivity nor its time to positivity. Funding Vancouver Coastal Health; St-Paul’s Hospital Foundation Emergency Department Support Fund; the Fonds de Recherche Santé – Québec (CPY); Intramural Research Program of the NIH, Clinical Center (AL); the Maricopa Medical Foundation


2002 ◽  
Vol 3 (3) ◽  
pp. 114-119 ◽  
Author(s):  
S. Cicalini ◽  
F. Palmieri ◽  
P. Noto ◽  
E. Boumis ◽  
N. Petrosillo

The use of central vascular catheters (CVC) is associated with a substantial number of complications, amongst which infections predominate. A diagnosis of CVC-related infection usually requires catheter removal for culture. Semiquantitative (roll-plate method) and quantitative methods (flush, vortex, centrifugation or sonication methods) are the most reliable diagnostic methodologies requiring catheter removal, because of their greater specificity. The roll-plate method is the simplest and most commonly used technique. This method only samples the external surface of the catheter, and is particularly indicated for recently inserted catheters in which extraluminal colonisation is the primary mechanism of infection. Luminal culture techniques, such as the quantitative methods, may be more relevant for catheters that have been in place for a long period of time. However, in up to 85% of removed CVC the culture is negative, and other diagnostic techniques that do not require catheter removal have been proposed, including paired quantitative blood cultures, endoluminal brushing, and differential time to positivity (DTP) of paired blood cultures. DTP, that compares the time to positivity for qualitative cultures of blood samples simultaneously drawn from the CVC and a peripheral vein, appears to be the most reliable in the routine clinical practice since many hospitals use automatic devices for qualitative blood culture positivity detection. More recently catheter-sparing direct diagnostic methods, which include Gram stain and acridin-orange leucocyte cytospin (AOLC) test, appeared to be especially useful because of the rapidity of results and the ability to distinguish different microorganisms, allowing early targeted antimicrobial therapy.


2019 ◽  
Author(s):  
Anna Damlin ◽  
Katarina Westling ◽  
Eva Maret ◽  
Cecilia Stålsby Lundborg ◽  
Kenneth Caidahl ◽  
...  

Abstract Abstract Background The diagnosis of infective endocarditis (IE) is based on microbiological analyses and diagnostic imaging of cardiac manifestations. Echocardiography (ECHO) is preferred for direct visualization of IE-induced cardiac manifestations. We investigated correlations between bacterial infections and IE manifestations diagnosed by ECHO. Methods In this cohort study, data from patients aged 18 years or above, with definite or possible IE admitted at the Karolinska University Hospital between 2008-2017 were obtained from Swedish National Registry of Endocarditis. Bacteria registered as pathogen were primarily selected from positive blood culture and for patients with negative blood culture, bacteria found in culture or PCR from postoperative material was registered as pathogen. Patients with negative results from culture or PCR were excluded. IE manifestations diagnosed by ECHO and risk factors were obtained from the registry. Chi-squared test and two-sided Fisher’s exact test was used for comparisons between categorical variables, and student’s ttest was used for continuous numerical variables; two-sided and skewed variables were log-transformed before these analyses. Multivariable analyses were performed using logistic regression. Associations and the strength between the variables were estimated using odds ratios (ORs) with 95% confidence intervals (CIs). P< 0.05 was considered significant. Results The most common bacteria were Staphylococcus aureus(n= 268, 47%) and viridans group streptococci (n= 127, 22%). The most common manifestations were vegetation in the mitral (n = 222, 36%), aortic (n = 214, 34%), and tricuspid valves (n = 117, 19%). Correlations were seen between aortic valve vegetation and coagulase-negative staphylococci (CoNS) and Enterococcus faecalis, between mitral valve vegetation and group B streptococci, tricuspid valve vegetation, andS.aureus, and between perivalvular abscesses and CoNS (all P< 0.05). Conclusions Correlations were found between certain bacteria and specific ECHO manifestations. Our study contributes to a better understanding of IE manifestations and their underlying bacterial etiology, which pathogens can cause severe infections and might require close follow-up and surgical treatment.


2007 ◽  
Vol 29 ◽  
pp. S244-S245
Author(s):  
St. Fokas ◽  
Sp. Fokas ◽  
G. Altouvas ◽  
M. Tsironi ◽  
S. Kaptanis ◽  
...  

2015 ◽  
Vol 139 (5) ◽  
pp. 621-626 ◽  
Author(s):  
Ron B. Schifman ◽  
Frederick A. Meier ◽  
Rhona J. Souers

Context The speed and accuracy of preliminary blood culture reports impacts patient management and outcomes. Objective To evaluate the accuracy and timeliness of preliminary blood culture results among multiple laboratories. Design Q-Probes participants collected turnaround time (TAT) data on preliminary Gram stains, compared accuracy of up to 100 preliminary to final culture Gram stain results, and described blood culture laboratory practices. Results Sixty-four laboratories and 5031 blood cultures were evaluated. All participants used continuously monitoring blood culture systems. Median TAT from initial growth detection to notification of results was 45 minutes, with the longest component being preparation of Gram stains (median time = 25 minutes). Participants (N = 40) reporting a continuous schedule for processing blood cultures had significantly lower overall TAT (medianm= 37 minutes) compared with 15 participants with intermittent processing schedules (medianm= 124 minutes),mPm= .003. Time to complete Gram stain processing was lower (median time = 21 minutes) for 39 participants using continuous processing schedule compared with 14 others (median timem= 67 minutes),mPm= .03. Goals for total TAT were used by 27 of 56 participants (48.2%). Having goals did not significantly affect TAT. A total of 4962 of 5021 Gram stain results (98.8%) agreed with final culture results. The highest discrepancy rates occurred among gram-positive bacilli (20 of 335; 6.0%) and mixed cultures (22 of 106; 20.8%). Conclusions This study provides benchmarks for assessing blood culture quality performance. Timeliness and accuracy of preliminary blood culture reports were excellent. However, nearly one-third of laboratories did not process blood cultures continuously. This significantly prolonged reporting results, which could affect patient outcomes.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S145-S146
Author(s):  
Miguel A Chavez ◽  
Satish Munigala ◽  
Carey-Ann Burnham ◽  
David K Warren

Abstract Background Staphylococcus aureus bacteremia (SAB) is a major cause of mortality. Recovery of SA may be enhanced with new blood culture systems resulting in a longer observed duration of bacteremia. Methods We performed a 24-month retrospective study of adults hospitalized with SAB at a 1250-bed academic hospital. Between 1/2018-12/2018 the VersaTREK system was used and 1/2019-12/2019 the BACT/ALERT VIRTUO (VIRTUO) system was used. We excluded patients without an Infectious Diseases (ID) consult. We defined SAB duration as short (1–2 days), intermediate (3–6 days), or prolonged (&gt;7 days). We compared SAB detection and management pre- and post-implementation of VIRTUO. Results 456 patients had SAB during study period; 420 (92%) had ID consultation: 178 (42%) pre- and 242 (58%) post-implementation. Similar proportion of methicillin-resistant SAB was seen (44.9% pre- vs. 36.8% post-implementation, p=0.09). Post-implementation, patients were more likely to have intermediate (22.4% pre- vs. 40.1% post-implementation; p&lt; 0.001) and prolonged SAB duration (3.9% pre- vs. 13.6% post-implementation; p&lt; 0.001). Median time to positivity for the index blood culture was shorter (19.9 pre- vs. 15.0 hours post-implementation, p&lt; 0.001). Dual anti-staphylococcal therapy was used more frequently in the post-implementation period (6.2% pre- vs. 15.7% post-implementation, p=0.003). No difference was noted in frequency of diagnostic studies (transesophageal echocardiography, magnetic resonance imaging, and computed tomography). Source control was similar (46.1% pre- vs. 45.0% post-implementation; p=0.84) but the median time to source-control was shorter post-implementation (4 pre- vs. 2 days post-implementation; p=0.02). Median planned duration of intravenous antibiotics did not vary between pre- and post-implementation periods (6 vs. 6 weeks, p=0.31). There was no difference in 90-day readmissions (38.2% pre- vs. 34.3% post-implementation; p=0.41). Conclusion VIRTUO blood culture system decreased time to positivity and increased frequency of prolonged SAB compared to the VersaTREK system. This resulted in increased use of dual anti-staphylococcal therapy and shorter time to source-control, but no difference in interventions, planned duration of antibiotics, or readmissions. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 73 (6) ◽  
pp. 406-412
Author(s):  
Tharntip Sangsuwan ◽  
Rungtip Darayon ◽  
Silom Jamulitrat

Objective: To determine blood culture contamination rates, and display with a g-chart.Materials and Methods: The medical records of patients, from whom blood cultures were obtained in a university hospital, during January and December 2019 were retrieved and reviewed for contamination. The Center for Disease Control and Prevention (CDC) criteria were used to classify the blood culture results. The contamination rates were illustrated with a g-chart.Results: We identified 331 false-positive blood cultures, among 32,961 cultured specimens; yielding a contamination rate of 1.0% (95%CI = 0.9% – 1.1%). The highest contamination events occurred in the Emergency department (49.2%), Pediatric ICU (5.2%) and Neonatal ICU (4.8%), respectively. The most common commensal bacterial genus were Staphylococcus coagulase negative (67.1%), Bacillus spp. (10.2%) and Corynebacterium spp. (7.6%), correspondingly. The g-charts could identify 14 abnormal variations, in 41 locations.Conclusion: The contamination rates found were within ranges of other reports. G-charts are simple to construct, easy to interpret and sensitive for detection of real time epidemics.


2021 ◽  
Author(s):  
Koshi Ota ◽  
Daisuke Nishioka ◽  
Yuri Ito ◽  
Emi Hamada ◽  
Naomi Mori ◽  
...  

Abstract Background: Blood cultures are indispensable for detecting life-threatening bacteremia. Little is known about associations between contamination rates and topical disinfectants for blood collection in adults.Objective: We sought to determine whether a change in topical disinfectants was associated with the rates of contaminated blood cultures in the emergency department of a single institution.Methods: This single-center, retrospective observational study of consecutive patients aged 20 years or older was conducted in the emergency department (ED) of a university hospital in Japan between August 1, 2018 and September 30, 2020. Pairs of blood samples were collected for aerobic and anaerobic culture from the patients in the ED. Physicians selected topical disinfectants according to their personal preference before September 1, 2019; alcohol/chlorhexidine gluconate (ACHX) was mandatory thereafter, unless the patient was allergic to alcohol. Regression discontinuity analysis was used to detect the effect of the mandatory usage of ACHX on rates of contaminated blood cultures.Results: We collected 2,141 blood culture samples from 1097 patients and found 164 (7.7%) potentially contaminated blood cultures. Among these, 445 (20.8%) were true bacteremia and 1,532 (71.6%) were true negatives. Puncture site disinfection was performed with ACHX for 1,345 (62.8%) cases and with povidone-iodine (PVI) for 767 (35.8%) cases. The regression discontinuity analysis showed that mandatory ACHX usage significantly reduced the blood culture contamination rate by 9.6% (95% confidence interval (CI): 5.0%–14.2%, P <0.001).Conclusion: Rates of contaminated blood cultures were significantly lower when ACHX was used as the topical disinfectant.


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