How Aspergillus Develops Antifungal Resistance and Causes Illness

In the Environment
Image of a fungal network in the grass and in the soil, with a zoom in microscopic view, showing a floral-like structure with circular spores.

Aspergillus fumigatus (A. fumigatus) is a fungus in the environment that is common in air. People can develop severe infections by breathing it in.

Image of a sprayer container, labeled as “fungicide” containing azoles.

Azole fungicides are sometimes used to kill fungi that harm crops. These fungicides are similar to the azole antifungal medicine used to treat people who become sick with A. fumigatus.

An image of a plant before and after fungicide treatment. The plant on the left is infected by a fungus, with a microscopic view of the fungal spores. An arrow with a sprayer bottle of fungicide containing azoles indicates treatment of the plant. The arrow points to a treated plant, now infected with two types of fungi, resistant and non-resistant to azoles.

Azole fungicides kill most A. fumigatus in the environment, but resistant A. fumigatus can survive and multiply.

Image of a patient in a hospital bed.

People with weakened immune systems can become infected with resistant A. fumigatus by breathing it from the environment or developing it in their bodies. These infections are hard to treat and life-threatening.

In a Patient
Image of a fungal network in the grass and in the soil, with a zoom in microscopic view, showing a floral-like structure with circular spores.

Aspergillus fumigatus (A. fumigatus) is a fungus in the environment that is common in air. People can develop severe infections by breathing it in.

Image of a year calendar with January through May crossed out, and a pill bottle labeled as and “Antifungal” containing azoles.

Some patients with chronic A. fumigatus infections take azole antifungals over a long time.

Image of a man before and after antifungal treatment. The man on the left is infected by a fungus, shown as blue dots entering through his nose and into his lungs. And arrow with a pill bottle of an antifungal containing azoles indicates treatment. The arrow points to the treated man, now with two different colored dots within his lungs, indicating resistant and non-resistant fungal spores.

Azole antifungals will kill most of the A. fumigatus in the body, but sometimes the fungus can become resistant to the medication and multiply.

Image of a patient in a hospital bed.

People with weakened immune systems can become infected with resistant A. fumigatus by breathing it from the environment or developing it in their bodies. These infections are hard to treat and life-threatening.