Provider Advisory

FOR IMMEDIATE RELEASE

Fatal Case of Histoplasmosis Suspected to be Acquired in Whitman County

This is an advisory from the Whitman County Public Health (WCPH) Disease Prevention Team regarding a recent fatal case of histoplasmosis that is suspected to be acquired locally in Whitman County.

Histoplasmosis is a disease caused by inhalation of the environmental fungus Histoplasma capsulatum, typically found in soil contaminated with bird or bat guano (feces). Histoplasmosis is common in the areas around the Ohio and Mississippi River Valleys; however, the range of suitable habitat likely extends across the eastern United States as well as some areas of the western U.S., including eastern Washington. Depending on host immune status and exposure intensity, a range of manifestations can occur, generally after a 3-17 day incubation period. This includes asymptomatic, acute or chronic pulmonary, or life-threatening disseminated infections. Reactivation infections may also occur months or years after exposure, generally following an immune compromising event. No direct human-to-human transmission has been reported. Histoplasmosis also does not spread between animals and people.

Alert Categories

Current Situation

Earlier this year WCPH was notified of a fatal case of histoplasmosis in a Whitman County resident. Public health investigation identified no travel outside Washington in the previous year and no lifetime travel to areas of high endemicity for histoplasmosis.

We are working closely with Washington State Department of Health and CDC on this case.

Actions Requested

Health Care Providers are requested to do the following:

1. Consider histoplasmosis or other fungal etiology in a patient with community acquired pneumonia of unknown etiology who is not responding to a course of empiric antibiotics or who reports notable exposures to bird or bat droppings.
2. Consider testing for H. capsulatum in patients with clinically compatible symptoms (CDC: Testing Algorithm for Histoplasmosis).
   
   1. Common symptoms of acute histoplasmosis include fever, cough, chest pain, headache, myalgias, shortness of breath, or rash (erythema nodosum/erythema multiforme).
   2. Reactivated infections are more likely to present in immunosuppressed persons as disseminated histoplasmosis, with gastrointestinal ulcerations, or masses, skin or mucosal lesions, lymphadenopathy, pancytopenia, hepatosplenomegaly, meningitis, encephalitis or focal brain lesions.
   3. People most likely to be exposed to histoplasmosis include, but are not limited to, the following: farmers, pest control workers, construction or excavations workers, poultry keepers, landscapers and gardeners.
3. Report to Whitman County Public Health any patient who:
   1. lives or works in Whitman County AND
   2. meets clinical criteria (as described above) AND
   3. has positive laboratory testing for histoplasmosis or an epidemiological link to a confirmed case.
4. Consider referencing guidance from the Infectious Disease Society of America for treatment of mild or moderate acute pulmonary histoplasmosis (2025) and archived guidance which includes treatment of severe or disseminated histoplasmosis (2007).

Testing & Diagnosis

CDC recommends ordering enzyme immunoassay (EIA) urine antigen tests. Clinicians may consider obtaining a serum specimen to test concurrently for antibody by immunodiffusion (ID) or complement fixation (CF) which may increase sensitivity of diagnosis; false positives from previous infection can occur, but antibody positivity typically wanes within three years after infection.

Imaging can be notable for: pulmonary infiltrates, cavitation, enlarged hilar or mediastinal lymph nodes, or pleural effusions.

Disseminated infection is more common in immunocompromised patients and can present with gastrointestinal ulcerations, or masses, skin or mucosal lesions, lymphadenopathy, pancytopenia, hepatosplenomegaly, or meningitis, encephalitis or focal brain lesions.

Resources

• Clinical Overview of Histoplasmosis (CDC)
• Diseases & Conditions: Histoplasmosis (Mayo Clinic)
• What Workers Should Know about Histoplasmosis (CDC)

Questions or Concerns?

We're here to help.

• Contact the Whitman County Public Health Disease Prevention Team at 509-397-6280.
• Visit cdc.gov/histoplasmosis for more detailed national guidance.

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© Whitman County Public Health Dept. 2025