From the Guidelines
Persistent candidemia is defined as the continued presence of Candida species in the bloodstream despite appropriate antifungal therapy, specifically referring to positive blood cultures for Candida that persist for more than 72 hours after initiating adequate antifungal treatment. This condition is a significant concern due to its association with high morbidity, mortality, and impact on quality of life. The management of persistent candidemia requires a comprehensive approach, including escalation of antifungal therapy, removal of potentially infected catheters, and a thorough search for metastatic foci of infection.
Key considerations in the management of persistent candidemia include:
- Escalation of antifungal therapy to an echinocandin like caspofungin (70mg loading dose followed by 50mg daily) or micafungin (100mg daily), or liposomal amphotericin B (3-5mg/kg/day) for severe cases, as recommended by the Infectious Diseases Society of America 1.
- Removal of all potentially infected catheters, as catheter retention is associated with worse outcomes in patients with candidemia 1.
- A thorough search for metastatic foci of infection, including endocarditis, endophthalmitis, and osteomyelitis, to ensure comprehensive management of the infection.
The underlying pathophysiology of persistent candidemia involves biofilm formation by Candida species, which protects the organisms from both host immune defenses and antifungal medications, contributing to persistence despite seemingly appropriate therapy 1. The clinical significance of persistent candidemia is highlighted by its association with increased mortality rates compared to candidemia that resolves quickly with treatment, making aggressive management essential 1.
In terms of specific management strategies, the use of echinocandins, such as caspofungin or micafungin, is recommended for most episodes of candidemia and invasive candidiasis, due to their strong safety profile, convenience, and early fungicidal activity 1. Additionally, the removal of potentially infected catheters is crucial, as catheter retention is associated with worse outcomes in patients with candidemia 1.
Overall, the management of persistent candidemia requires a comprehensive and aggressive approach, prioritizing the patient's morbidity, mortality, and quality of life outcomes. The most recent and highest quality study, published in 2016 by the Infectious Diseases Society of America 1, provides guidance on the management of candidiasis, including persistent candidemia, and should be consulted for specific recommendations on antifungal therapy and catheter management.
From the Research
Definition of Persistent Candidemia
- Persistent candidemia is defined as the isolation of the same Candida species for ≥5 days from blood cultures 2, 3, 4.
- This definition is used to distinguish persistent candidemia from non-persistent candidemia, which is an important distinction in clinical practice.
- The definition is based on the time-dependent analysis of blood culture results, which helps to identify patients with persistent candidemia.
Clinical Significance of Persistent Candidemia
- Persistent candidemia is a recognized complication of candidemia, associated with high mortality, increased length of hospital stay, and significant economic burden 5.
- The clinical significance of persistent candidemia includes the need for prolonged antifungal treatment, increased risk of complications, and higher mortality rates.
- However, some studies have found that persistent candidemia is not associated with higher 30-day mortality rates or inadequate therapeutic management 4.
Risk Factors for Persistent Candidemia
- The presence of a central venous catheter (CVC), metastatic infection foci, and ineffective empirical treatment are independent risk factors for persistent candidemia 3.
- Other risk factors include non-ocular complications, previously undetected sites of infection, and delayed source control.
- Early source control and removal of CVC are key elements in preventing persistent candidemia 3.