Patrick D Crowley, DO explains the impact of the "skip phenomenon" in Staphylococcus lugdunensis infective endocarditis, linking it to longer hospital stays and higher mortality rates.
The “skip phenomenon” (SP) refers to a clinical pattern in which blood cultures intermittently test positive before eventually clearing. A recent study sheds light on the fact that one-third of patients with Staphylococcus lugdunensis infective endocarditis (S lugdunensis IE) experience the SP, and these patients tend to face prolonged bacteremia, extended hospital stays, and a higher 1-year mortality rate. In an exclusive email interview, Patrick D Crowley, DO, from the Mayo Clinic’s Division of Public Health, Infectious Disease, and Occupational Medicine, discussed the significance of this phenomenon, its impact on clinical practice, and the implications for patient care.
Crowley: "'Skip Phenomenon' occurs in patients with positive blood cultures who are receiving antibiotics. One set of their blood cultures are negative for 24 hours, but the blood cultures turn positive the next day. This one day of negative cultures is the “skip”. This SP has only been described in Staphylococcus aureus, until now with Staphylococcus lugdunensis infective endocarditis."
Crowley: "The first step to identifying SP is to know that it can occur. Previously, if a set of blood cultures had no bacterial growth, the team would not repeat cultures and would treat the patient like there was not bacteria in their blood anymore. If SP happens and the bacteremia recurs in the blood the next day, that puts patients at risk for an infection in central lines or surgically implanted material. Thus, if a patient has bacteremia with S aureus or S lugdunensis, we suggest waiting until there are two consecutive days of negative blood cultures prior to placing central lines or surgically implanted material to reduce risk."
Crowley: "Skip phenomenon may indicate either that patients are more vulnerable - sicker, frailer, older - or that S lugdunensis infection is more severe or has spread to a location not identified - such as the spine, large muscles, joints, or brain. If SP occurs, clinicians should consider whether the patient has an infection somewhere else. They should ask about new joint pain, back pain, check for confusion, and consider whether other imaging - such as a brain or spinal MRI or PET-CT is needed. Infective endocarditis is a difficult disease to diagnose and treat, and should be managed by an Infectious Diseases specialist."
The SP causes intermittent positive blood cultures in S lugdunensis IE, complicating diagnosis.
SP leads to longer bacteremia, extended hospital stays, and higher mortality.
Delaying central line placement until two negative cultures and early specialist care are crucial for better outcomes.
Crowley: "I think the mortality is higher in the patients with SP due to patient and disease factors outlined above. Staphylococcus lugdunensis infective endocarditis is a disease with high mortality. Over one fourth of patients without SP died as well. However, it is worth noting that we had a small study sample and it would be helpful to look into a larger number of cases to describe mortality rates and whether there are other contributing factors that we can address."
The skip phenomenon in S lugdunensis IE presents unique challenges for clinicians, with implications for treatment, monitoring, and patient outcomes. Crowley’s insights underscore the importance of awareness in managing these patients, particularly as they are at greater risk for prolonged infection and higher mortality rates. The findings also highlight the need for further research to understand these dynamics better and improve clinical interventions.
