Although caving in Jamaica is a thrilling experience there is one big danger:

HISTOPLASMOSIS!!

• Histo-what?
  
  histoplasmosis is a fungal infection that converts to a yeast infection within one's body. The disease is a non-transmittable acute often self-limiting infection of the lungs resulting from unusually heavy inhalation of the airborne spores of the fungus Histoplasma capsulatum.




• O.K. histoplasmosis, but what has this to do with cavers?
  
  The growing conditions for the fungus are warmth (more than 20 - 24 °C), moisture and soils with lots of humus and animal excrement (especially the excrement of bats and blackbirds). That's why the thick layers of guano in the Jamaican bat caves are an ideal breeding ground for this fungus. Other high-risk zones are old chicken houses, barns, belfries, pigeon lofts,... anywhere that there is soil with an accumulation of bat and/or bird excrement.




• Do you find it only in Jamaica?
  
  NO! It is important to know that all tropical bat caves over the world are potential breeding grounds for histo. So you can get in Jamaica, but also e.g. Cuba, Puerto Rico, Mexico, Central and South America, Canada and also in the United States (Ohio, Missouri, Mississippi, Virginia, Maryland,...). People who grew up in these regions may already have developed some resistance against the disease.




• Big Warning about caving in Africa !!!!
  
  Histoplasmosis capsulatum has an African brother: Histoplasmosis duboissi . This disease appears in the west and in the middle of Africa. It hits particularly the lymph nodes, subcutaneous connective tissue and can expand in other organs like the liver and spleen. Cold abscesses, bone and joint aberrations arise. The result is most of the time fatal. Take care while caving in Africa!




• And the old continent?
  
  Read what A.G. Fincham, et al, wrote about us Europeans in their article "Histoplasmin sensitivity among cavers in Jamaica" :
  
  Cavers of European origin are particularly useful in studies of Histoplasma distribution in caves since the organism is almost unknown in Northern Europe and Asia (Edwards and Billing, 1971). Frankland (1974), in a discussion of the study of the incidence of histoplasmosis infections amongst cavers, said that "The Northern European speleologist would seem to be a particularly suitable experimental animal for such studies coming from a non-infected area and being guaranteed to probe deeply into any underground focus of infection wherever he goes." :)




• What are the symptoms of histo?
  
  The early symptoms are flu-like: fever, headache, cough, hot-cold feelings, cold shivers, loss of appetite, shortness of breath, hoarseness, joint and muscle pains. But in many patients there is a deep feeling of discomfort just under the breastbone.
  People who develop symptoms usually develop them within a week to 10 days of contracting the infection; then the symptoms frequently vanish within four or five days. Normally your immune system will keep the infection under control so that it does not severely damage your lungs or other organs in your body.
  
  But it is very important to understand that histo is NOT curable. This means that it will stay in your body for the rest of your life. You can have a perfect normal life once you have histo, but there are things you need to know so that histo will not reactivate and do significant damage to your lungs and possibly move into other parts of your body.
  First and foremost: Do NOT take steroids unless you are in a life-threatening situation. Steroids artificially depress one's immune system. If that happens, your histo can reactivate, even after a period of 50 years!




• Are you immediately sick?
  
  No, the incubation period is usually 3 to 18 days, with an average of 10 days.




• Is it contagious?
  
  No, the illness is not contagious.




• When you have histo what is the treatment?
  
  Most people's immune systems will control histoplasmosis without any treatment. Others, however, who develop more severe forms of histo will probably need antifungal treatment and possibly other kinds of treatment as well.




• Are there complications?
  
  There is a possibility depending on the number of spores that are inhaled and your general health condition. People with weakened immune systems are at the greatest risk for developing severe and disseminated histoplasmosis. Included in this high-risk group are persons with AIDS, lupus and/or other immune disorders or people receiving immuno-suppressive drugs.
  
  
  • Mild infection: Light flu-like symptoms. Lasts one to three days. If you are living in a region where the organism is endemic and/or you already have histo, chances are great you will belong to this category.
    
  • Acute lung infection: The "cavers disease". This is self-limiting and affects only the lungs. Even without treatment you will be better in two weeks up to three months. Although as a caver you may think that this is the only form of histo you can contract, this is clearly not true. You can develop all the mentioned forms of histo along with serious complications.
    
  • Chronic histoplasmosis: Looks like tuberculosis on a chest x-ray. CT scans are more distinctive in diagnosing histo. Unfortunately you will also need to tell the medic what histo is as most health care professionals have never treated anyone with this disease. Otherwise you could end up with a useless treatment against tuberculosis.
    
  • Disseminated infection: a rare form of the disease, the fungus has spread throughout the body. Serious symptoms: loss of weight, extreme tiredness, anemia...The patient often dies within four to ten months without treatment.
    



• Damned, how can we prevent to get it?
  
  This is a difficult one.
  
  
  • The perfect solution is not entering caves... O.K. I know.
    
  • You can try to wear respirators. Yeah, try it in a hot tropical cave, chances are great you will suffocate.
    
  • Next try, don't make dust. The spores are living in it. But now I have heard that you can get histo in wet caves too.
    
  • Try medication. Cavers have tried experimental prophylactic doses of Sporanox (Itraconazole) or Nizoral (Ketoconazol).
    Take care: these medication can have severe side effects. Before experimenting please take contact with your doctor for his advise.
  
  Currently there is no way to prevent histo. Think twice before entering tropical bat caves.
  
  This page was made together with Katharyn Waldron.
  
  
  P.S. You want to read more about histo? Go to the LINKS page.
  
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  You want more info? mail me: guy.van.rentergem@skynet.be