Preventing Deaths from Histoplasmosis

Histoplasmosis is an infection caused by a fungus called Histoplasma capsulatum.  The fungus lives in the environment in the central and eastern United States, parts of Central and South America, and other areas of the world. People can get histoplasmosis after breathing in the microscopic fungal spores from the air, although most people who inhale the spores don’t get sick.

Histoplasmosis sometimes affects healthy people (particularly people who are exposed to soil in endemic areas that contains large amounts of bird or bat droppings), but the infection often goes away without antifungal medication. However, histoplasmosis can be very serious in people who have weakened immune systems, such as people with cancer or HIV/AIDS.

Why is histoplasmosis a problem?

• In Latin America, histoplasmosis is one of the most common opportunistic infections among people with HIV/AIDS, and the mortality rate ranges from 20–40%.
• The signs and symptoms of histoplasmosis are very similar to those of other respiratory infections such as tuberculosis (TB), which may lead to delays in diagnosing and treating histoplasmosis appropriately.
• The standard methods available to diagnose histoplasmosis, such as culture or histopathology, often require invasive procedures to obtain a sample for testing. In addition, culture can take days to weeks to produce results, and histopathology has limited sensitivity, meaning it doesn’t always detect the infection.

What CDC is doing to prevent deaths from histoplasmosis

• CDC is working with partners in the private sector and international government and non-governmental organizations to develop ways to diagnose histoplasmosis faster and more reliably.
• A new enzyme-linked immunosorbent assay (ELISA) can detect Histoplasma antigen in urine, and is potentially faster, cheaper, and more sensitive than traditional diagnostic methods. Earlier, more reliable diagnosis of histoplasmosis can prevent deaths by:
  • Minimizing delays in treatment
  • Saving money and resources spent looking for alternate diagnoses, and
  • Reducing unnecessary treatment for other suspected illnesses.
• CDC is helping build laboratory capacity to diagnose histoplasmosis and establish laboratory-based surveillance in several Latin American countries to better understand the public health burden of histoplasmosis.