With as nimble and mobile as they are, one thing is for sure: bats get around. Not only are bats notable for flying long distances to migrate, they also spend large swaths of time packed close together with other members of their colony, in their preferred cave, abandoned building, or other roost.
Because of their close proximity to each other, it’s not surprising that bats transmit some communicable diseases among themselves. And, because bats are mammals, they are prone to rabies infections. But, rabies isn’t the only bat-borne disease that poses a danger to humans—in this article, we’ll be taking a closer look at the variety of diseases bats are known to carry, and we’ll be dispelling some myths related to the topic.
Photo Credit: Diego Tirira on Flickr
Typical Bat Diseases
Let’s address our question head-on before moving forward: “Do bats carry diseases?”
Yes, they do.
Bats are capable of carrying multiple diseases, in fact, and it’s possible for a bat to be infected with more than one kind of communicable infection. So, how many bat-borne diseases are there, and should humans be concerned about them?
As it turns out, there are more than 60 different viral strains of diseases that bats have been shown to carry. These are viruses that are capable of being spread from one species to another, and they’re referred to as ‘zoonotic’ viruses. Some of the more notable zoonotic, bat-borne viruses include:
- Henipaviruses. The largest of the bats—the Fruit Bat—is particularly known to carry viruses that fall under this category.
- Hantaviruses. Although Hantavirus strain outbreaks among bats appear to be relegated to parts of Africa and Sierra Leone, these viruses can still spread into neighboring regions.
- Coronaviruses. The Severe Acute Respiratory Syndrome (or SARS) virus of worldwide infamy falls under the category of Coronaviruses.
- Filoviruses. These viruses are damaging to the circulatory system, and they can spread from bats to monkeys and back again.
While these infections could arguably be considered ‘exotic’ because of the locales in which they’re known for spreading, they are still cause for concern for anyone living remotely near them. Some of these viruses are potentially fatal, including the one disease that is most commonly associated with bats: rabies.
Rabies Infections Via Bats
Bats are mammals and as such, they are prone to rabies infections if and when they come into close contact with a carrier of the disease. Rabies infections that stem from bat bites in particular have been proven to be fatal, with a documented case in 1988 tracing an encephalitis death directly to a bat bite.
In North America alone, there are normally between 1-3 deaths that occur every year due to rabies infections received from encounters with bats. These infections typically occur when a bat bites a human and the rabies virus that is active in the bat’s saliva is transferred into the bloodstream of the bite victim.
This may lead some to believe that most bats carry rabies or that even a lot of bats carry rabies. The truth is that, according to the Centers for Disease Control, most bats do not have rabies. The CDC found that after taking a sample of the blood from bats captured in the wild, only around 6% of them were shown to be infected with the rabies virus. Another study conducted by Arizona State University revealed that less than ½ of 1% of bats are actively rabid.
This may not seem like much of a consolation to someone who has just been bitten by a bat. After all, bat colonies can be quite large, with some of them easily eclipsing the 250,000 mark. Even if only 1% of a colony of 250,000 bats had rabies, that means 2,500 rabid bats within that colony take to the skies every time the colony heads out to hunt at night.
Because of the clear rabies risk that is posed by bats, it is highly advised that you never, ever attempt to handle a bat in the wild, even if it is grounded and/or sick or injured. An injured bat may feel threatened, and there’s no telling what behavior it might illicit when picked up or transported by someone who isn’t wearing protective gloves and who isn’t trained to deal with such an animal.
Remember that most rabies infections can be fairly well managed through the prompt administration of medication and wound care. Even still, dealing with a rabies infection isn’t something you want to have ruin your trip to Thailand.
If you do find a bat in need of rescue or medical help, contact your local animal control instead of trying to relocate the bat yourself.
Bat Guano: An Unlikely Source of Disease
It’s not enough that bats carry multiple communicable diseases, many of which can be fatal. As it turns out, their feces can be a source of damaging illnesses, as well.
As bat droppings accumulate below the roost of a group of bats, it can become a fertile source of nutrients for invasive organisms. The longer the roost has been active, the more nutrient-rich the ground below it becomes. After all, bats aren’t known for cleaning up after themselves.
Over time, fungal spores can be released from the bat guano into the surrounding air. Then, when a human or other animal comes into contact with the affected air, the spores can be inhaled and thus an infection of Histoplasmosis can occur. While this disease isn’t particularly fatal in every case, it can cause death, which provides yet more reasoning for not disturbing bat roosts if they’re discovered in the wild.
Smaller accumulations of bat guano aren’t necessarily considered threatening. However, established roosts that have been active for multiple years should be treated with extreme caution.
Respect Bats; Stay Healthy
Hopefully, this article has given you some things to consider when it comes to the subject of bats and diseases.
We’ve shown that, while bats have been proven to carry multiple different contagious diseases, fatal infections from them are rare. What’s more, if medical treatment can be obtained shortly after a bite or scratch from a rabid bat, the prognosis is generally good and recovery can be nearly assured.
We’ve also explored an unlikely source of bat-related disease: bat guano.
The overarching theme here is that bats should be treated with caution, just like any other wild animal that is encountered in their natural habitat. While it may be tempting to provide aid to a grounded bat by scooping it up and bringing it home, we’ve showed why this is an objectively bad idea.
Treat bats with respect, observe their privacy, and you shouldn’t find yourself at all afflicted with any of the ailments bats can proffer.