Histoplasmosis epidemiology and demographics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Serge Korjian M.D., Aravind Kuchkuntla, M.B.B.S[2]

The incidence of histoplasmosis is estimated by the Centers of Disease Control to be around 500,000 every year in the United States. In the United States, an estimated 60% to 90% of people who live in areas surrounding the Ohio and Mississippi River valleys (where Histoplasma is common in the environment) have been exposed to the fungus at some point during their lifetime.

Histoplasmosis is the most common endemic fungal infection in the United States and parts of Mexico and South America.

• The incidence of histoplasmosis is estimated by the Centers of Disease Control to be around 500,000 every year in the United States.^[1]
• The incidence of histoplasmosis in adults aged 65 years and older in the U.S. is estimated to be 3.4 cases per 100,000 population.
• Rates are highest in the Midwest, with an estimated incidence of 6.1 cases per 100,000 population.

• In the United States, an estimated 60% to 90% of people who live in areas surrounding the Ohio and Mississippi River valleys (where Histoplasma is common in the environment) have been exposed to the fungus at some point during their lifetime.
• The true prevalence of chronic histoplasmosis infection is unknown.
• Histoplasmosis in Europe without travel to endemic areas is rare.

• Histoplasma capsulatum is distributed worldwide, except in Antarctica, but most often associated with river valleys.
• It is most commonly reported in the Ohio and Mississippi river valleys in the United States, but is observed throughout the Midwestern and Southern US.
• Histoplasmosis is reportable in the following states and U.S. territories:^[2]

• Alabama
• Arkansas
• Delaware
• Illinois
• Indiana
• Kentucky
• Michigan
• Minnesota
• Mississippi
• Nebraska
• Pennsylvania
• Puerto Rico
• Rhode Island
• Wisconsin

• Outbreaks have been reported associated with travel to many countries in Central and South America, most often associated with visiting caves.^[3]

• Infants and adults aged 55 years and older are at higher risk of developing the disease.^[2]

• Histoplasmosis does not have any gender or race predilection.

• Histoplasmosis also is endemic in parts of Asia, Southeast Asia, and India.
• In China, 75% of cases occur along the Yangtze River, and is usually seen in patients with AIDS.
• Histoplasmosis is especially a problem in areas of the world where antiretroviral therapy (ART) is not widely available, because ART helps keep HIV-infected people from reaching the stage where they are most vulnerable to histoplasmosis and other opportunistic infections.
• In Latin America, for example, histoplasmosis is one of the most common opportunistic infections among people living with HIV, and approximately 30% of HIV/AIDS patients diagnosed with histoplasmosis die from it.^[4]