More information about IFI caused by molds

Molds are a type of fungus. They are all around us. Molds are common in soil, decaying food, air, and water. They cause little harm to most people. But when mold spores (tiny pieces of fungus) are breathed in, they can sometimes infect the lungs, sinuses, or other body organs. This is more likely if a person already has a serious illness or a weakened immune system (see What puts a person at risk for IFI due to molds? below).

Many different types of molds can infect the body. The most common type is called Aspergillus. It usually infects the lungs, but can also infect the sinuses, brain, or other organs. When Aspergillus causes serious infection, it is called aspergillosis or when found in the lungs, fungal pneumonia. Another type of mold that can cause serious infection is called Mucorales. When Mucorales cause serious infection, it is called mucormycosis.

These infections are rare but are becoming more common. They are most likely to occur in people with specific risk factors (see below). At one cancer hospital, more than 10% of people who had a certain type of stem cell transplant developed an invasive mold infection within 12 months after their transplant.

These infections can be very serious. Aspergillosis may lead to death in up to 41% of the people who get this type of infection.

Some of the factors that can increase a person’s risk include:

• Having a low white blood cell count for a long time (such as people with blood cancers)
• Getting a stem cell or solid organ transplant
• Using steroid medicines
• Having AIDS or other specific immune system diseases
• Having uncontrolled diabetes
• Living in certain climates (mold growth is affected by temperature, humidity, rainfall, and wind)

Signs of IFI caused by molds, such as fever, are common to other types of infections. So, it can be hard for doctors to tell that a mold is the problem, even using imaging tests like x-rays. They may try to take a sample of blood or body tissue and look at it under the microscope (microscopy) or see if anything grows from it (culture). Results from these tests can take some time. Different kinds of tests are becoming available that may help doctors more quickly diagnose IFI due to molds.

Doctors will choose an approach based on the person being treated and the specific type of mold causing the infection. Treatment may include antifungal medicine, as well as surgery, if the mold is growing in a part of the body where it can be removed. Other ways that doctors may try to help fight the infection include:

• Giving medicines to increase white blood cells in the body if the person's white blood cell count is low
• Reducing the amount of other medicines that may affect the immune system
• Treating any problems related to the person’s metabolism such as controlling blood sugars in patients with diabetes