1821. Clinical Characteristics of Staphylococcus aureus Bacteremia with the Skip Phenomenon: a Case Control Study.


 
 
 Staphylococcus aureus bacteremia (SAB) is one of the most common causes of persistent bacteremia, which is associated with complicated disease and poor clinical outcome. “The skip phenomenon (SP)” was recently proposed concept which might exhibit fluctuating blood culture positivity, but its clinical significance remained to be clarified. The aim of the study was to evaluate the clinical characteristics of SAB with the SP.
 
 
 
 This is a retrospective case-control study conducted at 1141-bed university hospital during 2006-2021. Adult inpatients with more than 3 days of SAB were included. Cases were patients with SP, and controls were the rest of the patients. Duration of bacteremia was defined as bacteremic days under active antibiotic therapy counting the first day as day 1. SP was defined as at least 1 day of negative blood cultures following documented S. aureus bacteremia and preceding recurrence of a positive blood culture, which was taken within 14 days from last positive culture. Patient characteristics including medical comorbidity, implanted hardware, and focus of infection were reviewed.
 
 
 
 Of the 149 patients, 17 (11.4%) had the SP. A total of 20 skip phenomenon episodes among 17 cases were observed. Three patients had 2 episodes of SP. Of the 20 episodes of the SP, 7 (35.0 %) were confirmed with single set, and 13 (65.0 %) were confirmed with 2 sets of negative blood culture. The median interval from first positive blood culture to first SP episode in each case was 7 days (interquartile range [IQR], 6-16 days). Of 20 episodes of SP, 18 (90.0 %) were accompanied with fever as an indication for taking blood culture. The cases (n=17) were more likely than controls (n=132) to have a longer duration of bacteremia (median [IQR], 14 [11–36] days, vs 4 [3–7] days; p < 0.001), and diabetes mellitus (52.9 % vs 25.0 %, p=0.023). There was no significant difference in deep-seated infection (64.7 % vs 48.5 %, p=0.303), methicillin resistance rate (76.5 % vs 50.0 %, p=0.068), and 90-day mortality (17.6 % vs 27.3 %, p=0.561) between cases and controls.
 
 
 
 Our findings suggest that we should consider to take blood culture repeatedly when clinically indicated, even if we confirmed the negativity once before.
 
 
 
 All Authors: No reported disclosures.
