Humans & bats evolved to live in frequent proximity, yet rarely meet. That keeps us both safe.
ORLANDO, Florida––The January 14, 2018 death of Ryker Roque, 6, at the Arnold Palmer Hospital for Children in Orlando, just 20 minutes from Disney World and half an hour from Walt Disney’s Wild Animal Kingdom, came as a shocking reminder to most people who heard about it that the U.S. is still a rabies-endemic nation, and that anyone can become infected and die if bitten by a rabid bat.
As bats are the most numerous and broadly distributed of mammals, found in almost the whole of North America, a rabid bat may be encountered almost anywhere.
We need bats more than bats need us
But this scarcely means bats are bad news. Devouring as many as 600 mosquitoes per hour of flying time, bats may contribute even more than insecticides to keeping us safe from mosquito-borne diseases, which kill more than a million people per year, worldwide. Bats also have an essential role as pollinators.
Indeed, despite the rabies risk from bats, humans need bats much more than bats need us. White nose disease, for example, a fungal ailment which may spread in part through human intrusions into bat caves, and is almost as deadly to bats as rabies is to us, is believed to have killed more than six million bats in 31 states since 2006, and is still uncontrolled.
Insecticides also kill bats, as does much other human activity, mostly without human awareness that bats are harmed.
The best way to handle a bat encounter is to not handle the bat
Because all bats inhabiting the U.S. and Canada are strictly nocturnal air-feeding insectivores, who rarely fly at human head height or lower, most Americans and Canadians enjoy the benefits of having bats around while rarely seeing a bat, seldom thinking about bats except at Halloween, and never having trouble with bats.
Therein lies the risk. Because most Americans and Canadians rarely if ever encounter bats, most have little idea what to do if they find a bat on the ground, in an attic, under a bridge, or elsewhere, or if a bat flies through an open door, window, or ceiling trap door into their home.
That the best way to handle a bat encounter is to not handle the bat is not as widely known as it should be. Most bats found indoors will quickly exit, if a nearby door or window is left open. There is no need to chase the bat, hit the bat, or scare the bat. If the bat circles, the bat is probably looking for a way to escape.
Many bat species cannot take off from the ground
Practically unknown is that most bat species rarely if ever descend to the ground voluntarily, and many bat species cannot take off from the ground.
Typically bats roost upside down, clinging to the insides of hollow tree trunks, wood walls, or cave ceilings, and fly by dropping into a glide.
Bats found hanging upside down or crawling along a vertical or elevated wood surface tend to be healthy and in no need of human intervention.
If a bat is found grounded, the bat is probably seriously ill or injured.
A rescue can be attempted by scooping the bat up gently with a long-handled shovel, then using the shovel to catapult the bat as high into the air as possible. Healthy bats glide into flight, usually as soon as they start to fall back down, and soon disappear. A bat who crashes usually would not survive long anyhow, and might even be rabid.
Nothing involving a bat should be done without wearing a long-sleeved shirt, long pants, a hat, and work gloves. Insectivorous bats who bite humans must be presumed rabid, since humans are not easily mistaken for insects.
Bat bites, unfortunately, are often not recognized by the victims, tending to be no larger and no more painful than mosquito bites. Wash any body part that has had direct contact with a bat immediately with soap and hot water for about five minutes, then seek medical attention if there is any sign of a wound or blemish, no matter how apparently trivial.
Let the doctor determine whether a bite has actually occurred. This is something that victims and others who have never actually seen bat bites are notoriously poor at recognizing, sometimes with fatal consequences. Bats tend to have long but narrow fangs, leaving deep but almost invisible and sometimes painless punctures.
Though Roque’s death was reported in news briefs by media from Orlando to New York City to Houston, less information about rabies avoidance accompanied most of the reports than accompanied scattered mentions in October 2017 that an unidentified middle-aged woman had died from a rabid bat bite in Sebring, Florida, after failing to seek treatment.
Sebring is about three hours’ drive south of Roque’s home in Eustis, Florida. Every major Florida city, from Jacksonville in the north to Miami in the south, is within a three-hour radius of either Sebring or Eustis.
Wildlife management & public health response
If the two Florida bat rabies victims had died from one of the rabies strains occurring in terrestrial mammals in North America––dog, fox, skunk, or raccoon––news of the deaths might have been followed by vigorous attempts to eradicate the rabies source and protect other vulnerable animals. Escalated efforts would be made to enforce the vaccination requirements for dogs. Baited doses of the oral rabies vaccine––Raboral––would be hand-distributed and perhaps even air-dropped in likely habitat for the host species while cold winter weather permits.
Public health authorities, veterinarians, and agricultural extension services would urge people to vaccinate all domestic mammals against rabies, as a precaution. Rabies can infect and kill cats, cattle, goats, sheep, horses, indeed almost any mammal, with opossums the lone native or common North American species never known to become rabid in the wild. But even opossums have become infected in laboratory experiments.
Dogs, foxes, skunks, raccoons, and bats are the only frequent carriers of rabies, simply because rabies tends to kill species other than those that host endemic strains so quickly that that they have little opportunity to inflict a rabid bite before becoming incapacitated by the combination of high fever and weakness in the hindquarters that accompanies the onset of the “furious” rabies phase that precedes paralysis and death.
Another way to put this is that only dogs, foxes, skunks, raccoons, and bats are likely to carry “dumb” rabies, meaning rabies without obvious visible symptoms.
Oral rabies vaccines tend to break down and lose effectiveness in warm weather, limiting the opportunity to vaccinate terrestrial mammals to just a few weeks in most of the southern U.S., and a few months in the northern states.
Sold only to government agencies, made to special order, Raboral doses are custom-tailored to release the vaccine through the action of the stomach enzymes of the target species. The same version of Raboral manufactured for use against fox rabies will also work in jackals, coyotes, dogs, and foxes, but the formulas made for use in vaccinating skunks and raccoons are different.
The combination of inoculating domestic species, using conventional vaccines, with distribution of Raboral to vaccinate wildlife, has reduced the numbers of rabid terrestrial mammals reported around the U.S. to fewer than 4,000 per year.
The Centers for Disease Control & Prevention announced in September 2007 that dogs are no longer believed to be a host reservoir for rabies in the U.S., although rabid dogs are occasionally imported by accident from abroad, or (rarely) wander into parts of the U.S. southwest from Mexico. Yet about five dozen dogs per year in the U.S. become rabid through contact with infected foxes, raccoons, skunks, and––especially––bats.
More than 2,000 rabid bats per year are found in the U.S., but because most bats live well away from human discovery, this is believed to be well below 1% of all the rabid bats at large.
“Old disease for bats in the New World”
Advises Pablo Beldomenico, wildlife moderator for the Program for Monitoring Emerging Diseases (ProMED), “Genetic evidence suggests that rabies is an old disease for bats in the New World. Bats from most of the bat species in North America, when sampled in sufficient numbers, have been found to be infected with rabies virus. Rabies viruses recovered from bats were shown to be distinct from rabies viruses recovered from terrestrial mammals, suggesting that these viruses evolved within their bat hosts. Bat rabies viruses of bats are genetically diverse, exhibiting mutations characteristic to each host bat species. It should be taken into account, however, that bat rabies can be transmitted to humans and their domestic animals, being infections almost always fatal, unless treated.
Agrees ProMED infectious diseases moderator Martin Hugh-Jones, “The anti-rabies vaccine should ALWAYS be given if you think you have been bitten, scratched, or contaminated with the blood or saliva of a suspected rabid animal in ALL cases.”
Why no bat rabies preventive vaccine?
Eventually a vaccine may be developed to attack bat rabies much as Raboral has enabled U.S. and European wildlife and public agencies to attack rabies in foxes, skunks, and raccoons. But because almost all insectivorous bats are air-feeders, who would not accept a baited vaccine pellet unless it flew like a bug, and because bats dwell in hard-to-access cracks and crevices, a bat rabies vaccine would have to be aerosolized, to be sprayed into bat habitat and inhaled, and would have to be bio-engineered to ensure that it could not harm other species who might also live in hollow tree trunks, caves, and attics.
Since an aerolized rabies vaccine for bats exists only in theory, awareness of bat rabies remains our first and most effective defense against it.
Lack of awareness killed Ryker Roque, the six-year-old Florida victim.
Ryker Roque loved finding and learning about animals. His mother, Michelle Roque, 49, told Orlando Sentinel reporter Jason Ruiter that he “returned from the woods across from his house nearly every day with either a dead bug or lizard in his hands. So when his dad, Henry Roque, 54, brought home a sick bat he found while working maintenance at the Quality Inn & Suites in Mount Dora, the first grader couldn’t resist and got too close to the nocturnal mammal — a seemingly harmless act that turned fatal.”
The sick bat lived in a bucket on the Roque family porch for four days.
“Cried at the thought of getting shots”
“In the middle of the night, something told me, ‘You need to get out there and get rid of that bat,’ ” Michelle Roque said. “Something was telling me it needed to go.”
Recounted Ruiter, “When Ryker was bitten, he told his parents the tiny cut on his finger was only a claw mark from the bat.
“He swore up and down that it was only a scratch and not a bite,” the mother said. “So I Googled it. It said to put his hand under hot water for five minutes.”
Henry and Michelle Roque, added NBC News reporter Maggie Fox, “knew they should have taken Ryker for immediate medical attention, but relented when Ryker cried at the thought of getting shots. A week or so later, Ryker complained of numb fingers and a headache. Henry feared he’d hit his head while playing and rushed him to the hospital.”
Elaborated Ruiter, “Ryker told his mom and dad he couldn’t feel his fingers. Within hours, his arm began to twitch, flinging from his side. Then he came down with a severe headache, became confused and couldn’t walk.”
The Arnold Palmer Hospital for Children put Ryker Roque into a medically induced coma, trying to save him with an experimental technique called the Milwaukee protocol. The idea is to slow the advance of the rabies infection toward the victim’s brain, while treating the fever and other symptoms, buying time for the victim’s own immune system to fight off the deadly virus.
“Ryker told me ‘I know you can fix this,’ and his hands were shaking before they put him down, and he said , ‘Daddy can you fix this?’ and I said ‘I’ll try, I’ll try to fix it,'” Henry Roque told ABC News.
Milwaukee protocol developer Rodney Willoughby, M.D., of the Children’s Hospital in Wisconsin, told media that since 2004 the protocol has saved the lives of at least two children in the U.S., and 18 people around the world, in about 80 attempts.
The first person to undergo the Milwaukee protocol, Jeanna Giese, was bitten by a rabid bat she was trying to carry out of her church on September 12, 2004. She was then 15. She became only the sixth person on medical record to survive rabies, and the first to escape severe brain damage.
“She’s doing wonderfully,” Willoughby said. “She never even missed a school year. “She’s married, had twin children, and is doing so well I never hear from her.”
The Milwaukee protocol in September 2017 saved a three-year-old boy who was bitten by a rabid dog in the Dominican Republic. In November 2017 the Milwaukee protocol saved a 14-year-old boy who with his brother and sister suffered vampire bat bites in Rio Unini, Brazil, a rural community on the Rio Negro, a major Amazon tributary––but the brother and sister died.
The Milwaukee protocol has also saved six vampire bat victims in the Amazon region of Peru.
Vampire bats sometimes prey on humans.
Castro da Silva, father of the Rio Unini survivor, told Claudia Tanner of The Daily Mail that “More than 88 people in our area were bitten by bats in 2017. We reported the incidents but never got help. Every day, for over a year, my 10-year-old daughter would get up drenched in blood from bites on her elbows, on her hands and to her toes. She suffered more than 20 lacerations during this period. But rabies symptoms took some time to appear.”
Vampire bats, fortunately, do not occur in North America. Yet any bat may be rabid, and the best approach to a bat is not to approach the bat at all.