Histoplasmosis

WHAT IS HISTOPLASMOSIS?

Histoplasmosis is an infectious disease caused by inhaling the spores of a fungus called Histoplasma capsulatum.  Histoplasmosis is not contagious; it cannot be transmitted from an infected person or animal to someone else.

Histoplasmosis primarily affects a person's lungs, and its symptoms vary greatly.  The vast majority of infected people have no apparent ill effects or experience symptoms so mild they don't seek medical attention and may not even realize that their illness was histoplasmosis.  

If symptoms do occur, they start between 3 and 17 days after being exposed and will appear as a mild, flu-like respiratory illness and has a combination of symptoms including fever, chest pain, dry or nonproductive cough, headache, loss of appetite, shortness of breath, joint and muscle pains, chills, and hoarseness.

HOW IS HISTOPLASMOSIS DIAGNOSED?

Histoplasmosis can be diagnosed by identifying H. capsulatum  in samples of a person's tissues or secretion, testing the patient's blood serum for antibodies to the microorganism, and testing urine, serum, or other body fluids for the H. capsulatum antigen.  On occasion, diagnosis may require a transbronchial biopsy.

WHO CAN GET HISTOPLASMOSIS AND WHAT JOBS AND ACTIVITIES PUT PEOPLE AT RISK FOR EXPOSURE OF H. capsulatum spores?

Anyone working at a job or present near activities where material contaminated with H. capsulatum becomes airborne can develop histoplasmosis if enough spores are inhaled.  After an exposure occurs, how ill a person becomes varies greatly and most likely depends on the number of spores inhaled and the person's age and how susceptible they are to the disease.

Few people will develop symptoms after a low-level exposure to materials contaminated with H. capsulatum spores.  However, longer periods of exposure to higher concentrations of airborne contaminated materials increase a person's risk of developing histoplasmosis.

LIST OF OCCUPATIONS AND HOBBIES THAT MAY PUT PEOPLE AT RISK FOR EXPOSURE
  • Bridge Inspector or Painter

  • Chimney Cleaner

  • Construction Worker

  • Demolition Worker

  • Farmer

  • Gardener

  • HVAC Service Worker

  • Microbiology Laboratory Worker

  • Pest Control Worker

  • Restorer of Historic or Abandoned Buildings

  • Roofer

  • Spelunker (cave explorer)

WHAT CAN BE DONE TO REDUCE EXPOSURES TO H. capsulatum?

The biggest thing that can be done to reduce exposures to H. capsulatum is to exclude a colony of bats or a flock of birds from a building.  The best practice is to prevent the accumulation of manure in the first place.  When a colony of bats or a flock of birds is discovered roosting in a building, immediate action should be taken to exclude the intruders by sealing all entry points.  Any measures that might harm or kill bats or birds should be avoided and calling in a professional to help or fix the problem is always recommended!

Before exclusion of a colony of bats or a flock of birds it is important to give attention to the possibility of flightless young may be present and unable to leave.  This is especially important when considering exclusion of bats in the United States as they are a protected animal.

If a colony of bats is allowed to live in a building for an extended amount of time, manure will accumulate and create a health risk for anyone who enters the roosting area and disturbs the material.  Once a roosting site is discovered in a building an exclusion plan should be made and the extent of the contamination should be determined and discussed. 

 

Removing the bat manure is not always the next step.  Sometimes simply leaving the material alone if it is in a location where no human activity is likely, may be the best course of action.

Learn more about if you need a Bat Guano Clean Up here.

Guano Clean Up

Information provided by the Department of Health and Human Services; CDC, NCID, and NIOSH