RABIES! The perception - the reality
There Are Facts You Need To Know...
June 01, 2008
|Bat strain rabies is the rabies strain most commonly encountered in Michigan. Karrie Nash photo |
Rabies has terrorized humanity since the dawn of civilization. Fantastic fables, serious stories, silly superstitions (bats nesting in human hair) and modern day pass-it-along Internet inaccuracies fuel misperceptions of rabies. It is all very understandable for fear and lack of science based knowledge is a catalyst to confusion. But one fact remains solid: Rabies is (almost always) a fatal disease.
Old World drawings of wolf packs pursuing horse drawn sleighs -- and consuming the children that fell off as it lurched through the dark snowy woods may well be unrecognized recognition of rabid behavior. We will never know. But we do know that those tales produced great fear.
And last year when rabid coyotes on the east coast nipped humans a near rabid response of irrational human behavior followed the media reports. For months after those highly limited modern day encounters, every coyote seen on the fringes of suburbia became sensational. Rabies was presumed. The fact that most wild animals are not rabid and habituation to human presence can provoke bold behavior was all but ignored.
Our modern perception of rabies is a mulligan stew of information fueled in part by media reports. Many reports focus on the dramatic, the "furious"' stage; frothing at the mouth, acting wild, self mutilation (chewing on limbs) and snapping teeth. It makes for a good read. But the "dumb stage," often typified by docile or lethargic behavior, or simply wandering about that entices humans to pet; handle or try to help is just not as headline grabbing. And when there are no reports of rabid animals, even with an active rabies reservoir, we forget that the virus is out there.
In August of 2007 the Detroit News bannered a story that state health officials had discovered more animals with rabies than any time since the late 1950s. And then in March of this year in an excellent detailed front page story in the Flint Journal ("Rabies Rising") the strong rise of cases southeastern Michigan and the Muskegon area was noted. A good headline grabs readers, but many readers stop after the headline or lead paragraph unless the story has a personal interest. And when that happens, the science behind the story is lost.
Terrorized humanity in my lead for Woods-N-Water News is more eye catching than, "Rabies is an acute infectious disease of the central nervous system and here is what it means to you if you hunt or fish in Michigan." I chose those two words for drama, words that might scream more appropriately from a supermarket tabloid. But you are still reading.
The actual facts are less dramatic, and certainly not terrorizing, but should be of real concern for the reservoir of rabies in wildlife in all of North America is unknown and incidences with rabid animals, wild and domestic, increase in warmer weather. Statistically the threat of acquiring rabies in the United States is minuscule when compared to the hazards of every day life: drunk drivers, distracted drivers, artery choking grease burgers and cigarettes. And dozens are killed each year in Michigan on snowmobiles but phobia of that machine does not follow.
FACT: Rabies is here and rabies is a clear and present danger.
And the more people write about rabies the more people see animals that "might be rabid." Back in May of 2002 a pony on a popular school farm in Oakland County was confirmed as being rabid, leaving the Oakland County Health Department and Dr. Carol Bird, Chief of Medical Services, scrambling to reassure parents that petting the pony did not put children at risk. Reports of possible rabid wild animals skyrocketed following the rabid pony confirmation. But fact of the matter is most were not. A lactating raccoon drinking from an ornament pool on a hot day is far more likely thirsty, than rabid. But to the naive observer, a "night animal" out in day is rabid. And a bat swooping low behind a lawnmower on a sultry summer evening is in likelihood capturing bugs stirred up by the mowers passing, not searching for humans.
But on a global basis, rabies is the tenth most frequent cause of death from infectious disease, killing over 50,000 humans a year, yet literature searches reveals that rabies may be both under diagnosed and inaccurately diagnosed in the Unites States.
Confused? Health officials and State agencies are perplexed at times too.
The 2007 edition of the definitive text, Wilderness Medicine confirms that "Of 33,000 human rabies death reported world wide in 1997, scientific laboratory confirmation was available for less than 5%." To add to the confusion on rabies, we tend to think the R word and quickly imagine a mental picture of dog frothing at the mouth or a rabid bat swooping through a hunting cabin. It's not that simple: Nature is subtle and the rabies virus hides.
As outdoorsmen or women, there are facts you need to know. The word rabies is used loosely as a catch all but there are multiple variants or strain of rabies, each one linked to a singe mammal species. All are transmissible to humans and lethal if left untreated.
Too add to the confusion the reports of the frequency of rabies and the mostly likely carriers can be inaccurate: Statistics are open to various interpretations. Some states only test animals that have bitten humans or pets for rabies testing, others test all collected specimens. Some rabid animals die quickly, some die slowly. And it's a lot easier to pick up a bat flopping on a lawn or carried home by the family cat than it is to capture a skunk walking in circles or a coyote or fox that seems to be rabid. In the U.S. and Canada it's estimated that perhaps 90% of rabid wild animals die undetected and untested.
Is the perceived risk of acquiring rabies the reality?
Are you at risk from bats, bears and other beasts? Look south for one answer.
Indiana ran one of the longest running studies of rabies in bats. Between 1966 and 2003 they tested 8,262 bats for rabies. 5.4%, a headline grabbing 445 bats were confirmed as rabid. But what seems to be a plague of rabies was not. The Journal of Wildlife Management in their research article "Bat Rabies in Indiana" documented that bats used in the research were mostly incapacitated bats that people found sick or dead rather than normally behaving bats. NONE of the 259 normally behaving big brown bats examined from areas where rabid bats had occurred was rabid. The article empathized that the percentage of bats infected with rabies is not the percentage of rabid bats in the overall population.
When contacted for this article, John Whitaker, Jr. of the Center for North American Bat Research and Conservation at Indiana State University added, "There were 24 human deaths from rabies from 1990 to 2000, which is a lower mortality than almost anything you can think of that causes mortality at all - bee stings, dog bites, what have you." Whitaker added, "The perception of the public is very different from reality. Many people think that half or even more of the bats flying around are rabid. However the number rabid is only 5% of the suspect bats (varies with the species) and in reality the percentage of rabid of the normally acting (non-submitted bats) is probably way below one percent."
Dr. Kim Sings, Epidemiologist of Zoonose Diseases at the Michigan Department of Community health confirmed that like Indiana, Michigan tests the bats that come into contact with human, not random samples from the wild. Last year 1,800 bats were submitted for testing with 10.8 percentage positive for rabies, an almost doubling of numbers from previous years and perhaps, not surprisingly most of those rabid bats came from in and near population centers: Southeast Michigan, Greater Lansing and Muskegon.
MDNR wildlife biologist Thomas Cooley of the state's Wildlife Diseases Lab added, "When it comes to the most likely animal for a human to have an encounter with (in or around their homes) it would be a bat. We do have skunk-strain rabies in the state with the thumb being historically the most likely location to find the strain," Cooley emphasized that when it comes to statewide rabies strains, the bat-strain would be the most likely followed by the skunk-strain.
You are off to the northwoods or just hiking a southeast Michigan State Recreation Area or barbecuing in the backyard. What do you need to know to stay rabies safe?
First a basic fact, that even with the recent surge or confirmed rabid bats in Michigan the overall number of rabies cases has dropped over the past 60 years. Back in the 1930s dogs were the largest transmitters of rabies to humans. With mandatory vaccination, rabies carried or transmitted by dogs is unlikely; although most dogs bites - from off leash undocumented dogs - result in rabies treatment in emergency rooms and county health departments. In Michigan, bats, skunks, fox and raccoon are the most likely carrier, but all mammals, including cats, dogs, cows and horses are susceptible.
According to the Michigan DNR, bat rabies is the primary strain identified today. As a result it is the focus of most of the public attention. (Our Department of Community Health in Lansing does the testing. At the community health laboratory, a slice of brain tissue is treated with a fluorescent dye places under a microscope and if there is a 'glow' when exposed to ultraviolet light the specimen is rabies positive.) Even though the last case of human rabies in Michigan was reported in Hillsdale County (1983) - believed to be from a bat - common sense dictates avoid bats. But if one is "acting funny" it should be submitted for testing if it can be captured safely. But you should not be grabbing bats with ungloved hands for testing. All furbearers are of potential concern.
In Ohio and Ontario the raccoon strain rabies is spreading, a fact worth noting since rabies knows no borders. At press time, according to Dr. Signs of the Michigan Department of Public Health, this rabies strain has reached the east side of Ohio. Michigan remains at risk with published studies in Ohio acknowledging that as rabies continues to spread across the Buckeye state it might well become the route through which raccoon rabies leap frogs into Michigan. Ohio, like New York, Vermont and Ontario has been fighting to limit the spread of raccoons in raccoons by establish vaccine corridors (akin to the function of fire breaks in wildland firefighting) sometimes with aerial drops of vaccine hidden in fishmeal, or hand placed in some habitats. Although these oral vaccine barriers have slowed rabies according to researchers at Cornell University, it is unknown when new outbreaks may occur and how fast it will spread.
One issue of real concern is the illegal and legal transportation of wildlife including the capture and release in new locations of wildlife by Wildlife Damage and Nuisance Wildlife Control Permit holders, who may unknowing take infected animals over a present or future barrier zone. Its worth nothing that raccoon rabies was first diagnosed in Florida in 1947 and is now found in all eastern state up to Maine. The virus made a huge leap northward with the help of man when in the late 1970s, over 3,000 raccoons were transported from Florida and released in West Virginia to stock private hunting clubs. Others were released in Kentucky. And in March of 2003, Virginia had their first human fatality from raccoon rabies, a previously healthy 25 year old male. According to the CDC he became symptomatic before the diagnosis of rabies was made - too late for effective treatment.
Michigan has developed a Contingency Plan for the Management of (RSR) Raccoon Strain Rabies. This cooperative effort is developing an enhanced surveillance system for the early detection of RSR in the hopes that if an outbreak - or single case - is confirmed it can be contained to the area. The detailed report, not yet widely noted among many sportsman includes these two critical statements, "To implement a rabies control program such as described in this proposal, this enhanced rabies surveillance must be initiated before the disease becomes endemic in wildlife and must be sustained for as long as rabies continues to be reported in terrestrial animals in regions surrounding the rabies free area. Because raccoon strain rabies also affects other terrestrial carnivorous and unvaccinated domestic animal, surveillance cannot be limited to raccoons alone, and in fact, the presence of raccoon strain of the virus in Michigan may be detected first in other species such as in cats and dogs."
The report empathizes the differences in rabies. While most public literature in Michigan focuses on bats, the RSR contingency plan states clearly, "The submission of bats in contact with humans and domestic animals must continue to be part of the regular rabies control activities. However, bat rabies is an independent cycle from raccoon strain rabies, and a rabies case in a bat will not imitate a rabies control response." As Federal and State agencies and departments of health and the CDC monitor the rabies situation, all outdoor recreationists need to know the what ifs. What if a bat scratches you? What if a fox snaps at your leg? What if a raccoon bites your hand? The what ifs are endless.
Rabies exposure is a medical urgency, not a lights and siren medical emergency. There is no need to race for the ER from the hunting lodge. But any bite by a wild mammal, or undocumented domestic pet dog, cat, ferret, horse, cow or other mammal must be suspect and taken extremely seriously. Failure to have immediate follow up can lead to death. And there are actions you need to take first.
• Immediately wash the area with soap and water, be it a bite or the tiniest of scratches, or just saliva on your skin. Soap destroys the protective overcoat of rabies virus.
• If there is a safe way to confine the animal, do so. Do not destroy the head. A dead animal can be kept on ice-double bagged. Always wear gloves and clean any tools with one part bleach to nine parts water. Notify your health department and Michigan DNR if it is a wild animal, health department and local police if the animal is domestic. Let them know what happened to the animal. A coffee can with a lid can hold a bat.
• Seek medical attention through your physician or hospital emergency room as soon as possible. You will likely receive a series of post exposure rabies prophylaxis human rabies immune globulin and vaccine: a non-painful series of life saving shots.
According to the National Association of State Public Health Veterinarians, Inc. "Rabies is transmitted only when the virus is introduced into bite wounds, open cuts in skin, or onto mucus membranes from saliva or other potentially infectious neural tissue." It is possible, but rare to contract rabies if infectious material from a rabid animal such as saliva gets directly into your eyes, nose or mouth. A bite or scratch by a large mammal can not be missed but you can have exposure with a bat without knowing under special circumstances because of their very small sharp teeth and the saliva factor.
• Bat found in the room of an unattended/sleeping child.
• Bat found in a room with a person under the influence of alcohol or drugs or with other sensory or mental impediment.
• You wake up in a cabin with bat "on you" but can't find bite mark.
When you are unsure of the exposure possibility always err on the side of caution and immediately share the circumstance of the encounter with health professionals. With rabies reports rising, warm weather here and the virus' insidious nature, caution is in order as we head for the woods, however the rabies situation in Michigan is not the premises of a bad Fox Network Special with foaming at the mouth crazed beasts leaping out from behind the trees and melting back into the underbrush. Rabies is simply a fatal disease that can usually be avoided and treated--when common sense is employed.
Jonathan Schechter is a naturalist/paramedic in Brandon Township, certified in Advanced Wilderness Life Support by the Wilderness Medical Society. His interest in rabies began in 1982 when he was exposed to a rabid bat in Oakland County and underwent post exposure prophylaxis treatment. Schechter can be reached at firstname.lastname@example.org. More detailed information can be found on rabies at CDS.gov/rabies and