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Histoplasmosis
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Infections

Histoplasmosis

Histoplasmosis is a non-contagious fungal infection caused by breathing in spores found in soil contaminated with bird or bat droppings.

What is histoplasmosis?

Histoplasmosis is an infection caused by a fungus called Histoplasma. This fungus is common in the central and eastern United States, particularly around the Ohio and Mississippi River valleys, and is also found in parts of Central and South America, Africa, Asia, and Australia. It thrives in the environment, especially in soil containing large amounts of bat or bird droppings.

Transmission

You contract histoplasmosis by breathing in Histoplasma fungal spores from the air. This typically occurs after activities that disturb the soil, such as farming, construction, or landscaping. Histoplasmosis is not contagious; you cannot catch the infection from another person or an animal.

Symptoms

Most people who breathe in the spores never develop symptoms. If symptoms do occur, they typically appear 3 to 17 days after exposure and may include:

  • Fever
  • Cough
  • Fatigue
  • Chills
  • Headache
  • Chest pain
  • Body aches

For most, symptoms resolve within a few weeks to a month. However, some individuals may experience longer-lasting or severe infections. Those at higher risk for severe infection include:

  • People with weakened immune systems (e.g., those with HIV, organ transplant recipients, or those taking immunosuppressive medications like chemotherapy or steroids)
  • Infants
  • Adults age 55 and over

Severe histoplasmosis can develop into a long-term lung infection or spread to other parts of the body, such as the central nervous system, a condition known as disseminated histoplasmosis.

Diagnosis

To diagnose histoplasmosis, a healthcare provider will:

  • Review your symptoms, medical history, and travel history
  • Perform a physical exam
  • Order blood, urine, or tissue tests to detect the fungus
  • Potentially order a chest x-ray or CT scan of the lungs

Treatment

While some cases resolve without intervention, treatment is necessary for severe pulmonary histoplasmosis, chronic cases, or infections that have spread throughout the body. Treatment involves prescription antifungal medicines, which may be required for 3 months to 1 year.

Frequently Asked Questions

For most healthy individuals with mild symptoms, recovery typically occurs within two to four weeks without specific antifungal treatment. However, you should see a doctor if symptoms last longer than two weeks, if you experience difficulty breathing, or if you have a compromised immune system. Early diagnosis allows for targeted treatment, which is critical for preventing the infection from becoming chronic or spreading to other parts of the body.
No, you cannot contract histoplasmosis from direct contact with animals, pets, or bird feeders. The infection is only acquired by inhaling airborne spores from the environment. While bird droppings can support fungal growth, the risk comes from the soil or dust beneath the droppings becoming disturbed and airborne, not from the birds themselves. Keeping feeders clean and avoiding digging in the soil directly underneath them is a sensible precaution, but the animals are not vectors for transmission.
While mild cases resolve on their own, signs of severe or disseminated histoplasmosis require immediate medical attention. Watch for symptoms that persist beyond a few weeks, such as high fever, significant weight loss, night sweats, or jaundice (yellowing of the skin or eyes). Neurological symptoms like confusion, severe headaches, or neck stiffness, as well as abdominal pain or liver enlargement, suggest the fungus may have spread to other organs. Individuals with weakened immune systems should seek care promptly if any respiratory symptoms appear.
To reduce the risk of inhaling spores, avoid disturbing dry soil or dust in areas with heavy bird or bat droppings. If you must work in such environments, wet the soil before digging to keep spores from becoming airborne, and wear a well-fitted N95 respirator. It is also advisable to avoid entering old, enclosed spaces like attics or barns that have not been opened in a long time without proper respiratory protection and ventilation.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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