The skip phenomenon in Staphylococcus aureus bacteremia: clinical implications

Serial blood cultures (BCs) are integral in managing Staphylococcus aureus bacteremia (SAB) to determine complication risks and treatment response. Several studies recognized the skip phenomenon (SP)- the occurrence of intermittent negative BCs and recommend obtaining additional BCs to document clearance. We examined patients with SP to determine its clinical significance. Significant differences between those who did and did not manifest the SP included higher rates of injection drug use and community-onset SAB in the SP cohort. Longer SAB duration, high-grade SAB, and complicated bacteremia were more common in the SP group. In unadjusted outcome analyses, association of SP with hospital length of stay was not significant, although a higher risk of in-hospital mortality among SP patients approached significance. Analysis of hospital survivors revealed no significant differences in 90-day relapse or 1-year mortality. Clinical implications of patients with SAB and SP indicate that serial BCs are warranted to document bacterial clearance.