Candidemia (Candida Bloodstream Infection)

How Candida enters the blood

Candida species normally live harmlessly on the skin and in the mouth and gut. They invade the bloodstream when defenses are breached:

• through the skin along a central venous catheter
• through the gut wall after abdominal surgery, perforation or severe illness
• when the immune system is weakened, especially with low neutrophils

Once in the blood, Candida can seed the eyes, heart valves, bones, liver, spleen and kidneys. This spread is called invasive candidiasis. See invasive candidiasis.

Species

Candida albicans used to cause most cases. Now non-albicans species are common, including C. glabrata (Nakaseomyces glabratus), C. parapsilosis (often linked to catheters), C. tropicalis and C. krusei. Some are less sensitive to fluconazole.

Candida auris is an emerging, often multidrug-resistant species that spreads between patients in hospitals and nursing homes, colonizing skin and surviving on surfaces. The CDC treats it as an urgent threat, and facilities use screening and strict infection control.

Risk factors

• central venous catheters, especially for long periods
• total parenteral nutrition (IV feeding)
• broad-spectrum antibiotics, which reduce competing bacteria
• ICU stay and mechanical ventilation
• abdominal surgery, particularly with leaks or pancreatitis
• neutropenia from chemotherapy, and stem cell transplant
• kidney failure needing dialysis
• premature, low-birth-weight babies
• injection drug use
• Candida colonization at multiple body sites

Symptoms

Symptoms are often nonspecific and look like bacterial sepsis:

• fever and chills, especially persisting despite antibiotics
• low blood pressure and a fast heart rate
• confusion or worsening general condition
• in some cases, small painless skin nodules, muscle pain, or vision changes from eye involvement

Diagnosis

• Blood cultures: the standard test, though they miss a significant proportion of invasive candidiasis. Several sets should be taken, and cultures repeated daily until negative.
• Species identification and antifungal susceptibility testing.
• (1,3)-beta-D-glucan blood test and Candida PCR support diagnosis in high-risk patients.
• Dilated eye exam by an ophthalmologist to look for chorioretinitis or endophthalmitis, ideally within the first week.
• Echocardiogram in persistent candidemia or with heart valve risks, to look for endocarditis.
• Imaging of the abdomen if deep infection is suspected.

Treatment

• Echinocandins (caspofungin, micafungin, anidulafungin, rezafungin) are first-line for most adults.
• Step-down to oral fluconazole after 5 to 7 days for patients who are stable, have cleared their blood, and have a susceptible species.
• Amphotericin B (lipid formulations) is an alternative, and used for some resistant infections.
• Remove central venous catheters promptly when they are the likely source.
• Duration: at least 14 days after the first negative blood culture and resolution of symptoms, longer with eye, heart or bone involvement.
• Antifungal prophylaxis is used in some very high-risk groups, such as certain transplant and leukemia patients and high-risk ICU patients.

Complications

• septic shock and organ failure
• endophthalmitis and vision loss
• endocarditis
• osteomyelitis, liver and spleen abscesses (especially after neutropenia)
• kidney infection

Outlook

Candidemia is serious. Studies report that around 30 to 40% of patients die during their hospital stay, often because of their underlying illness. Rapid antifungal treatment and line removal improve survival.

Prevention

• remove central lines as soon as they are no longer needed
• strict hand hygiene and sterile catheter insertion and care
• careful antibiotic stewardship
• screening and contact precautions for Candida auris

Frequently asked questions

What is candidemia?

Candidemia is a bloodstream infection caused by Candida yeast. It mostly affects people in hospitals, especially those in intensive care, with central venous catheters, on IV nutrition, after abdominal surgery, or with weak immune systems. It can spread to the eyes, heart and other organs.

What are the symptoms of Candida in the blood?

The most common sign is fever and chills that do not improve with antibiotics. Others include low blood pressure, rapid heartbeat and confusion. Some people develop skin nodules or blurred vision if the infection spreads to the eyes.

How is candidemia treated?

It is treated with an IV echinocandin antifungal, often switching to oral fluconazole once the patient is stable and the yeast is sensitive. Central lines are removed if possible, and treatment usually continues for at least 2 weeks after blood cultures turn negative.

What is Candida auris?

Candida auris is a drug-resistant yeast that spreads in healthcare settings and can cause serious bloodstream infections. It is hard to identify with standard lab methods and survives on surfaces, so hospitals use screening, isolation and special cleaning to control it.

Can you get candidemia from a yeast infection?

Very rarely. Ordinary vaginal yeast infections or oral thrush in healthy people do not spread to the blood. Candidemia usually occurs in seriously ill or hospitalized people with catheters, recent surgery, or severely weakened immune systems.