Histoplasmosis is another disease associated with bats. Its symptoms vary greatly, but the disease primarily affects the lungs. Occasionally, other organs are affected. When this happens it can be fatal if untreated.
In addition, Histoplasmosis is caused by a fungus that grows in soil and material contaminated with droppings from animals, including bats. Droppings, also known as bat guano, can contaminate the soil and cause infectious spores to be released when the soil is disturbed.
Even though it can be found throughout the world, it is widespread in certain areas of the U.S. and can be found in places that harbor large populations of bats, including caves.
While most infected persons have no apparent ill effects, antifungal medications are used to treat many forms of the disease.
Bats and Diseases around the World
Even though rabies and histoplasmosis can be found all over the world, some diseases associated with bats are found exclusively in certain regions of the world. Notably, research suggests that bats might be the source of several hemorrhagic fevers, which affect multiple organ systems in the body and often lead to life-threatening diseases.
One of these diseases is Marburg hemorrhagic fever, which is found exclusively in Africa. Past outbreaks have shown that Marburg Hemorrhagic Fever kills up to 90% of those infected.
While the natural host had for years been unknown, new research suggests that fruit bats are a natural source of this virus, and the virus has been isolated repetitively from fruit bats in Uganda.
The same may be true for Ebola hemorraghic fever.
The virus that causes this disease is often referred to as the "cousin" of Marburg virus, since they are the only distinct viruses that belong to a group of viruses known as filoviruses. Like Marburg, Ebola is highly fatal and is found mostly in Africa. Recent studies indicate that, as with Marburg, bats are likely to be a natural source of this virus, although no Ebola virus has been isolated from bats.
Two other viruses - Nipah (which causes Nipah virus encephalitis) and Hendra (which causes Hendra virus disease) - are also associated with bats. Research suggests that Hendra virus is associated with fruit bats (commonly called flying foxes) in Australia. Nipah and related viruses are also associated with the same group of bats in Southeast Asia and parts of Africa, although outbreaks of disease in humans have so far been limited to Malaysia, Singapore, India, and Bangladesh. Both viruses can cause severe respiratory and neurologic disease in humans.
Another group of viruses known as coronaviruses have been detected in multiple species of bats. Coronavirus infection can sometimes cause mild respiratory illness in humans, but these viruses were also implicated in the outbreak of Severe Acute Respiratory Syndrome (SARS) in Southeast Asia. While bats do not carry or transmit SARS, research has linked coronaviruses to bats in countries all over the world.
In addition, Lyssaviruses have been discovered on every inhabited continent. This group of viruses causes rabies, in addition to other diseases that can be fatal to humans. While current rabies vaccines are effective against many of the viruses in this group, several Lyssaviruses identified in Africa and Asia primarily associated with bats cannot be prevented with current rabies vaccines.
Further studies may shed light on the role of bats as the source of these viruses and their ability to transmit diseases caused by these viruses to humans.