What is invasive fungal infection (IFI)?

Invasive fungal infection, or IFI for short, is the name for many different serious infections caused by a fungus. IFI is important to understand because it can be very dangerous. It usually develops in people who are already sick or have a weak immune system. IFI can make it much harder to get better.

If you have an IFI or are at risk for one, this website may help you understand more about it. There is also a section for caregivers, or family and friends who help take care of people who have IFI. (Visit the Glossary for definitions of words that appear in bold type.)

More information about types of IFI

Molds and yeasts are both types of fungi. These fungi are not a kind of bacteria, but fungi are similar to bacteria in some ways. They live all around you. They can be in the air, soil, plants, and water. Most do not harm people, most of the time.

When a fungus gets into the body and makes you sick, this is called a fungal infection. You may have had athlete’s foot or a vaginal yeast infection. These are both kinds of fungal infections. They generally are not considered serious. But when a fungus spreads in the body and makes you very sick, this is called an invasive fungal infection. It can be life-threatening. A doctor needs to treat it right away.

Two of the more common fungi that can cause IFI are:

candida

Source:
Centers for Disease Control and Prevention. Definition of Invasive Candidiasis (03-02-2016).
http://www.cdc.gov/fungal/diseases/candidiasis/invasive/definition.html.
Accessed August 7, 2018.

Candida

A type of yeast

Can infect the bloodstream or body organs in people with weak immune systems

This infection may be called: candidemia, invasive candidiasis

aspergillus

Source:
Centers for Disease Control and Prevention. Aspergillosis (10-12-2017).
https://www.cdc.gov/fungal/diseases/aspergillosis/.
Accessed August 7, 2018.

Aspergillus

A type of mold

Can infect the lungs, sinuses, or other organs in people with weak immune systems

This infection may be called: invasive aspergillosis, invasive mold infection, fungal pneumonia

Fungi are different from bacteria and viruses

Fungi are different from bacteria and viruses
  • Many fungi can be seen with the naked eye—such as mushrooms and bread mold
  • Fungi live in the air, soil, plants, water, and even in the human body
  • Most fungi do not cause problems for people who are healthy
  • Unlike bacterial and viral infections, serious infections caused by fungi are rarely spread from one person to another

Yeasts and molds are the main types of fungi

Yeasts and molds are two types of fungi

Yeast

  • Often harmless, used in cooking
  • Can cause vaginal and mouth infections
  • Can cause serious, widespread infection in people with a weak immune system

Mold

  • Often found in warm, damp, and humid conditions
  • May cause allergy symptoms
  • Can cause serious, widespread infection in people with a weak immune system

Fungi can get into the blood, lungs, sinuses, brain, and other organs

Fungi can get into the different organs of the body

This is how fungi can get into the lungs

By breathing in spores, fungi can enter the lungs
  • Microscopic pieces of fungi can travel through the air
  • These tiny pieces are called spores
  • If you breathe in these spores and your immune system is weak, you could get an IFI in your lungs
  • Many fungi can also get into the body through the skin
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