Invasive candidiasis is an infection caused by a yeast (a type of fungus) called Candida. Unlike Candida infections in the mouth and throat (also called “thrush”) or vaginal “yeast infections,” which are localized to one part of the body, invasive candidiasis is a serious infection that can affect the blood, heart, brain, eyes, bones, or other parts of the body.

Candida normally lives inside the body (in places such as the mouth, throat, gut, and vagina) and on the skin without causing any problems. However, in certain patients who are at risk, Candida can enter the bloodstream or internal organs and cause an infection. A Candida bloodstream infection, also called candidemia, is the most common form of invasive candidiasis. In the United States, candidemia is one of the most common causes of bloodstream infections in hospitalized patients, and it often results in long hospital stays and death. It is also responsible for high medical costs.

Antifungal medication can treat invasive candidiasis. Certain patients such as those with cancer or bone marrow or organ transplants might receive antifungal medication to prevent invasive candidiasis.

Candidemia is one of the most common bloodstream infections in the United States. During 2013–2017, the average incidence was approximately 9 per 100,000 people; however, this number varies substantially by geographic location and patient population. CDC estimates that approximately 25,000 cases of candidemia occur nationwide each year.

Candidemia is the most common form of invasive candidiasis, but it does not represent all forms of invasive candidiasis because the infection can occur in the heart, kidney, bones, and other internal organs without being detected in the blood. In fact, the true burden of invasive candidiasis might be twice as high as the estimate for candidemia.

People who develop invasive candidiasis are often already sick from other medical conditions, so it can be difficult to know which symptoms are related to a Candida infection. However, the most common symptoms of invasive candidiasis are fever and chills that don’t improve after antibiotic treatment for suspected bacterial infections. Other symptoms can develop if the infection spreads to other parts of the body, such as the heart, brain, eyes, bones, or joints.

• People who have a weakened immune system (for example, people who have had an organ transplant, have HIV/AIDS, or are on cancerchemotherapy)
• Intensive care unit (ICU) patients
• People who have had surgery, especially gastrointestinal surgery
• People who have a central venous catheter
• Very low-birth-weight infants
• People who have taken broad-spectrum antibiotics
• People who have a very low neutrophil (a type of white blood cell) count (neutropenia)
• People who have kidney failure or are on hemodialysis
• People who have diabetes

Candida lives in and on the body

Candida, the fungus that causes invasive candidiasis, normally lives inside the body (in places such as the mouth, throat, gut, and vagina) and on the skin without causing any problems. In some people who are at higher risk for the infection, Candida can enter the bloodstream or internal organs and cause invasive candidiasis. For example, this can happen when a central venous catheter is inserted and left in place for a long time, during surgery, or when the immune system is weakened during chemotherapy. Healthcare workers can also carry Candida on their hands. A few outbreaks of candidemia have been linked to healthcare workers’ hands, so hand hygiene in healthcare settings is important for preventing the spread of infections.

Types of Candida

There are over hundreds of species of Candida, but only a few are known to cause infections. The most common species that cause infections are C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei.

Another species called C. auris is emerging as a cause of invasive candidiasis around the world and in certain areas of the United States.

Groups at risk for invasive candidiasis

People who are at high risk for developing invasive candidiasis include those who:

• Have spent a lot of time in the intensive care unit (ICU)
• Have a central venous catheter
• Have a weakened immune system (for example, people on cancer chemotherapy, people who have had an organ transplant, and people with low white blood cell counts)
• Have recently had surgery, especially multiple abdominal surgeries
• Have recently received lots of antibiotics in the hospital
• Receive total parenteral nutrition (food through a vein)
• Have kidney failure or are on hemodialysis
• Have diabetes
• Are pre-term babies

People who inject drugs are also at risk for invasive candidiasis, especially for bloodstream infections, heart valve infections, and bone and joint infections.

Is invasive candidiasis contagious?

Invasive candidiasis doesn’t spread directly from person to person. However, some species of the fungus that causes invasive candidiasis normally live on skin, so it’s possible that Candida can be passed from one person to another and possibly cause an infection in someone who is at high risk.

Preventing invasive candidiasis

• Antifungal medication. If you’re at high risk for developing invasive candidiasis, your healthcare provider may prescribe antifungal medication to prevent the infection. This is called “antifungal prophylaxis,” and it is typically recommended for:
  • Some organ transplant patients
  • Certain patients in the intensive care unit (ICU)
  • Patients who are on certain types of chemotherapy or have low white blood cell counts (neutropenia)
  • Patients who have a stem cell or bone marrow transplant and have low white blood cell counts (neutropenia)
• Some doctors may also consider giving antifungal prophylaxis to very low birth weight infants (less than 2.2 pounds) in nurseries with high rates of invasive candidiasis.
• Be a safe patient. There are some actions that you can take to help protect yourself from infections, including:
  • Speak up. Patients and caregivers can ask whether a central venous catheter (central line) is needed, and if so, how long it should stay in place. Tell your doctor if the skin around the catheter becomes red or painful.
  • Keep hands clean. Be sure everyone cleans their hands before touching you. Washing hands can prevent the spread of germs.
  • For more tips, please see CDC’s webpage about What You Can Do to Be a Safe Patient.
• Healthcare providers can follow CDC-recommended infection control practices every time they work with a central line.

How is invasive candidiasis diagnosed?

Healthcare providers rely on your medical history, symptoms, physical examinations, and laboratory tests to diagnose invasive candidiasis. The most common way that healthcare providers test for invasive candidiasis is by taking a blood sample or sample from the infected body site and sending it to a laboratory to see if it will grow Candida in a culture.

How long will it take to get my test results?

Results from a test will usually be available in a few days.

How is invasive candidiasis treated?

The specific type and dose of antifungal medication used to treat invasive candidiasis usually depends on the patient’s age, immune status, and location and severity of the infection. For most adults, the initial recommended antifungal treatment is an echinocandin (caspofungin, micafungin, or anidulafungin) given through the vein (intravenous or IV). Fluconazole, amphotericin B, and other antifungal medications may also be appropriate in certain situations.

How long does the treatment last?

For candidemia, treatment should continue for 2 weeks after signs and symptoms have resolved and Candida yeasts are no longer in the bloodstream. Other forms of invasive candidiasis, such as infections in the bones, joints, heart, or central nervous system, usually need to be treated for a longer period of time.