Histoplasmosis: Ohio River Valley Disease

Histoplasmosis: Ohio Vally River Disease

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Histoplasmosis a Common Ohio River Valley Disease

Histoplasmosis is a fungal infection that displays symptoms of tuberculosis. It is caused by certain airborne spores entering the lungs and growing as mold (Histoplasma).

It is commonly called Ohio River Valley Disease, Cave Disease, Spelunker’s Lung, or Darling’s Disease, named for Samuel Taylor Darling, who first diagnosed the condition in 1905 in Panama. The majority of cases in the United States develop in states east of the Mississippi River. Positive skin tests occur in as many as 8% of people who live in these areas.

It gets its name the Ohio River Valley Disease because the infection commonly occurs in this area.

It can affect dogs and cats; however, not spread by these animals. It is also not spread from person to person. The fungus grows in the soil then is transmitted to people and pets by contaminated bat guano and other bird droppings through touch and inhalation of spores in attics and other areas.

Histoplasmosis Symptoms

Histoplasmosis symptoms start 3-17 days after exposure, with an average of 12-14 days. Indications include flu symptoms, chest tightness and pain, shortness of breath, and severe cough — histoplasmosis patients are known to bruise or break ribs while coughing.

Some patients, however, develop no symptoms or simply present symptoms of a cold, which can delay proper treatment of the disease.

Severe cases of histoplasmosis are most often associated with a compromised immune system, such as in AIDS or cancer patients, or when lung function is depleted, as in COPD, emphysema, or chronic bronchitis. The most severe cases may require surgery to scrape the mold off the lungs.

Forms of Histoplasmosis

There are three forms of the disease: asymptomatic primary histoplasmosis, acute symptomatic pulmonary histoplasmosis, and chronic progressive disseminated histoplasmosis, the most debilitating form of the disease.

Asymptomatic Primary Histoplasmosis

Asymptomatic primary histoplasmosis is the most common form. It typically presents few symptoms in otherwise healthy people, except for some possible slight scarring of the lungs.

Acute Symptomatic Pulmonary Histoplasmosis

In acute symptomatic pulmonary histoplasmosis, there can be fever, muscle aches, headaches, and chills, along with non-specific respiratory symptoms. In 40%-70% of acute cases, chest x-rays may be normal, presenting a diagnostic challenge.

This disease can affect vision, causing tiny retinal scars called histo spots. Effects on the eyes often lay dormant for years when a histoplasmosis patient may start to see wavy lines, darkening vision, or loss of peripheral vision.

The acute form can also cause arthritis or pericarditis (inflammation of the sac surrounding the heart) when the immune system responds negatively to the unusual amount of fungal matter.

Chronic Progressive Disseminated Histoplasmosis

The third and most serious form is chronic progressive disseminated histoplasmosis. It involves mouth ulcers and lesions in the oropharyngeal areas. It can also affect the intestinal tract, adrenal, or central nervous system (CNS). In addition, many body parts can be affected, including the liver and bone marrow. Encephalopathy or meningitis is possible. Without quick diagnosis and treatment, this form can be fatal.

Diagnosis and Treatment

If the patient has no history of exposure to contaminants, it can be complicated to diagnose. A culture sample can take 2-12 weeks to grow enough to identify the fungus. Unfortunately, this can seriously delay proper treatment.

The disease is treated with antifungals such as Sporanox (itraconazole), Nizoral (ketoconazole), or amphotericin B (Fungizone, Amphocin). Dosage and route of administration are generally determined by individual patient conditions, and the treatment can last as long as six months or more.

In some cases, the disease can become dormant and reactivate during times of stress or illness.


To prevent histoplasmosis, avoid areas contaminated with bird or bat droppings, such as attics where birds and bats nest. In addition, avoid high dust areas such as farm fields when plowing as the plowing disturbs the contaminated soil. Flocks of nesting birds or bats can also significantly contaminate construction sites and caves. If you cannot avoid contaminated areas, ensure you have the proper equipment and protection from touching and preventing spores from entering the lungs.

Histoplasmosis can be controlled, but it is an insidious disease and can be deadly if not quickly and adequately treated.

Protection Against it by Hiring a Professional Wildlife Removal Company

As we mentioned, bats and birds are carriers of this fungus and can infect people and pets when their droppings, urine and feces are touched or inhaled. Therefore, it is critical to hire a professional wildlife removal company to eliminate them. Never attempt on your own without the proper protection and equipment.

The Critter Detective is a professional company you can trust to eliminate your wildlife animal problem safely and humanely. In addition to removing these wildlife animals, we offer repair of the damage they caused and cleanup of their droppings, urine and feces. Contact us today.