Histoplasmosis: A Common Fungal Lung Infection

Histoplasmosis is a lung infection caused by breathing in Histoplasma, a fungus that lives in the environment in certain parts of the United States and the world. Even though people living in or traveling to these areas regularly breathe in the fungal spores, most of the time, they do not get sick. People who get histoplasmosis can have mild to life-threatening symptoms of pneumonia.

Histoplasmosis is often misdiagnosed or diagnosed late because the symptoms are similar to more common pneumonias caused by bacteria or viruses. Delays in getting the appropriate treatment can lead to more severe illness or even death.

Learn about the symptoms and risks of histoplasmosis. Talk to your healthcare provider if you have concerns or think you might have histoplasmosis.

How It Spreads: From Soil to Lungs

People can get histoplasmosis by breathing in the fungus from the air. The fungus is typically found in soil and bird or bat droppings. Activities that stir up soil (like gardening) can increase the risk of histoplasmosis. Pets (dogs and cats) can also get histoplasmosis, but it does not spread between pets and people or from person to person.

In the United States, the fungus that causes histoplasmosis is mainly found in central and eastern states, especially in areas around the Ohio and Mississippi River valleys. It can also be found in other states and throughout the world.

Common Symptoms Can Lead to Delayed Diagnosis

Older man coughing

Symptoms of histoplasmosis include:

  • Fever
  • Cough
  • Fatigue (extreme tiredness)
  • Chills
  • Headache
  • Chest pain
  • Body aches

These symptoms usually appear 3 to 17 days after breathing in the fungus.

Diagnosis

If you have symptoms and suspect that you might have histoplasmosis, talk to a healthcare provider. They can test you for histoplasmosis by taking a blood or urine sample. They also may ask you to do imaging tests, like an x-ray or a CT scan of your lungs.

People at Higher Risk

Some people can develop severe histoplasmosis and get very sick. Groups who are at a greater risk for severe disease include:

  • People who have existing health problems or take medicines that lower the body’s ability to fight germs and sickness (people with weakened immune systems).
  • People over the age of 55.
  • People who are exposed to a large amount of the fungus, such as through their job.

A severe infection must be treated with prescription antifungal medicine. Some people might need to stay in the hospital.

Help Prevent Severe Illness

While it is not possible to avoid breathing Histoplasma in areas where it is common, avoiding some activities can help to reduce the risk of severe infection, such as:

  • Digging in soil, chopping wood, or anything that disturbs soil and natural surfaces with bird or bat droppings or known high levels of Histoplasma.
  • Cleaning, remodeling, or tearing down old buildings.
  • Exploring caves.
  • Cleaning chicken coops.

Large amounts of bird or bat poop should be cleaned up by a professional company that specializes in handling hazardous waste. A small amount of bird or bat poop on a hard surface is much less likely to spread histoplasmosis than a larger amount around soil or plants.

Before starting a job or activity where there’s a possibility of being exposed to the fungus that causes histoplasmosis, review  Histoplasmosis and Work.

Awareness Is Key

Knowing about histoplasmosis can help you and your healthcare provider know when to consider testing and treatment for infection.

Greater awareness about histoplasmosis is needed in the United States and around the world. In Latin America and the Caribbean, histoplasmosis is one of the most common infections among people living with HIV. There, about 1 in 3 people living with HIV who get histoplasmosis die from this condition. Learn more about CDC’s work to prevent deaths due to histoplasmosis by improving diagnosis and increasing access to lifesaving antifungal medications.

Estimated Areas With Histoplasmosis
This map shows CDC’s current estimate of where the fungi that cause histoplasmosis live in the environment in the US.

This map shows CDC’s current estimate of where the fungi that cause histoplasmosis live in the environment in the United States. These fungi are not distributed evenly in the shaded areas, might not be present everywhere in the shaded areas, and can also be outside the shaded areas. Darker shading shows areas where Histoplasma is more likely to live. Diagonal lines show the potential range of Histoplasma.

Fungal Disease Awareness Week
Fungal Disease Awareness Week 2022

Join CDC in sharing information to increase awareness in your community about fungal diseases during Fungal Disease Awareness Week.