Invasive Candidiasis

A serious Candida infection of the blood or internal organs

Table of Contents

Quick Facts

  • Type: Invasive fungal infection
  • Cause: Candida yeast entering the bloodstream or organs
  • Main risk: Hospitalized and immunocompromised patients
  • Seek urgent care: Fever and chills not improving with antibiotics

Overview

Invasive candidiasis is a serious infection caused by Candida yeast that has spread beyond the surfaces where it normally lives into the bloodstream or deep into the body's organs. Unlike a mild mouth or skin yeast infection, invasive candidiasis is a potentially life-threatening illness that almost always affects people who are already very sick, usually in the hospital.

When Candida enters the blood, the infection is called candidemia, and it can travel to organs such as the heart, eyes, brain, bones, and internal organs. Because the symptoms overlap with bacterial infections, invasive candidiasis can be hard to recognize, and prompt diagnosis and antifungal treatment are essential.

Symptoms

The symptoms are often nonspecific and resemble a serious bacterial infection. A key clue is fever that does not improve with antibiotics. Symptoms may include:

  • Fever and chills that persist despite antibiotic treatment
  • Feeling very unwell, weak, or fatigued
  • Low blood pressure and a rapid heartbeat in severe cases
  • Symptoms specific to an affected organ, such as eye pain or changes in vision if the eyes are involved
  • Abdominal pain if internal organs are affected

Because invasive candidiasis can progress to sepsis and organ failure, any seriously ill person with unexplained, persistent fever needs urgent evaluation.

Causes

Invasive candidiasis occurs when Candida yeast that normally lives harmlessly on the skin or in the gut gains entry to the bloodstream or deeper tissues. This usually happens through breaks in the body's natural barriers or when the immune system is weakened.

  • Central venous catheters and other indwelling lines that provide a route into the blood.
  • Recent abdominal or other major surgery.
  • Prolonged stays in an intensive care unit.
  • Broad-spectrum antibiotics that disturb the normal balance of microbes.
  • Weakened immune systems from chemotherapy, transplants, or HIV.

Risk Factors

  • Critical illness and a prolonged stay in intensive care
  • A central venous catheter or other indwelling medical device
  • Recent major surgery, especially abdominal surgery
  • Long courses of broad-spectrum antibiotics
  • A weakened immune system from cancer, transplant, or other causes
  • Diabetes
  • Premature birth in newborns

Diagnosis

Diagnosing invasive candidiasis can be challenging because symptoms are nonspecific. Doctors use several tests:

  • Blood cultures: The main way to detect Candida in the blood (candidemia), though they can take time and do not catch every case.
  • Blood biomarkers: Certain blood tests can help detect invasive fungal infection.
  • Imaging: Scans to look for infection in organs such as the abdomen, eyes, or heart.
  • Tissue or fluid samples from a suspected site of infection.

Because delays are dangerous, treatment is sometimes started before tests fully confirm the diagnosis in high-risk patients.

Treatment

Invasive candidiasis is treated with antifungal medication, usually given through a vein, along with controlling the source of infection.

  • Antifungal medications: Echinocandins are often the first choice, with fluconazole or other agents used depending on the specific Candida and the patient's condition.
  • Removing the source: Infected catheters or lines are usually removed.
  • Treating affected organs: Longer or specialized treatment is needed if the eyes, heart, or other organs are involved.
  • Supportive care: Intensive care support may be required for severely ill patients.

Treatment typically lasts at least two weeks after the blood clears, and longer if organs are involved. Follow-up, including an eye examination, is often recommended.

Prevention

  • Careful insertion and care of catheters and central lines in hospitals
  • Removing medical lines as soon as they are no longer needed
  • Using antibiotics only when necessary
  • Preventive antifungal medication for certain very high-risk patients, as decided by their care team
  • Good infection-control practices in healthcare settings

When to See a Doctor

Invasive candidiasis develops in people who are already seriously ill, usually in the hospital, so it is typically detected and treated there. Urgent medical attention is needed for any seriously ill or hospitalized person who has:

  • Fever and chills that do not improve with antibiotics
  • Signs of worsening infection or sepsis, such as low blood pressure and a racing heartbeat
  • New eye pain or vision changes during a serious infection
  • Confusion or rapid decline in someone with risk factors

Related Topics

Candidemia

Candida in the bloodstream, the most common form of invasive candidiasis.

 Esophageal Candidiasis

A less severe Candida infection of the swallowing tube.

 Sepsis

A dangerous body-wide infection that invasive candidiasis can cause.

 Oral Candidiasis

A common, milder Candida infection of the mouth.

Frequently Asked Questions

How is invasive candidiasis different from a regular yeast infection?

Ordinary yeast infections affect surfaces like the mouth, skin, or vagina and are usually mild. Invasive candidiasis is when Candida spreads into the bloodstream or deep organs, which is a serious, potentially life-threatening infection that almost always affects very ill or hospitalized people.

Who is most at risk for invasive candidiasis?

People in intensive care, those with central venous catheters, recipients of major surgery, people on long courses of broad-spectrum antibiotics, and those with weakened immune systems are at highest risk. Premature newborns are also vulnerable.

Why does fever that persists despite antibiotics suggest invasive candidiasis?

Antibiotics treat bacteria, not fungi. In a high-risk patient, fever that continues despite appropriate antibiotics can be a clue that a fungal infection such as invasive candidiasis is present, prompting doctors to test for and sometimes treat it.

How is invasive candidiasis treated?

It is treated with intravenous antifungal medication, often an echinocandin, along with removing infected catheters and treating any affected organs. Treatment usually continues for at least two weeks after the blood clears, and longer if organs are involved.

Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions about a medical condition.

References

  1. Centers for Disease Control and Prevention (CDC). Invasive candidiasis.
  2. National Institute of Allergy and Infectious Diseases (NIAID). Fungal diseases.
  3. MedlinePlus, U.S. National Library of Medicine. Candida infection.
  4. Infectious Diseases Society of America (IDSA). Candidiasis guidance.