By Erin K Costello and Emma Sands
As usual, this time of year we see an increase in posts asking for advice concerning animal bites and rabies. This is most likely due to spring and summer arriving (for those of us in the northern hemisphere anyways), bringing with them the beautiful weather needed for enjoying things like camping, hiking, walking outdoors, and other forms of activity that brings us humans, and our pets, closer to wildlife. Sadly, the advice being given in the anti-vax echo chambers is frightening. Many of these anti-vax groups and websites have an agenda to push, something we here at What’s The Harm, can relate to since we too have an agenda. Although, unlike the anti-vax communities, our agenda is solely the health and well being of our readers, regardless of how it is that you find this health and well being. We don’t have an anti-science message so we won’t judge if you use modern medicine, or alternative methods to achieve good health. If it works for you, great! We only become concerned when people are hurting themselves, their kids, or other people by chasing lies and ineffective treatments. Because of this, we feel it’s important to provide the facts concerning rabies, and inform readers what the medical community advises for those at risk of possible exposure. As always, if you have any concerns, questions, or fears, please consult your physician to discuss any further actions.
WHAT IS RABIES?
Rabies, or otherwise known as lyssavirus, is a zoonotic disease (transmitted from animals to people) that causes inflammation of the brain, which is almost always fatal. The virus is neurotrophic in nature, meaning the virus will specifically infect nerve cells and travel to the central nervous system through neural pathways. This will ultimately affect the central nervous system and cause acute encephalomyelitis (ADEM) in mammals. Viruses are different from bacteria and fungi, as they must be inside a host cell to replicate. After the rabies virus is transmitted (often from bat, fox, coyote bites etc) it is then able to replicate in a host cell.
In a host cell, viruses can hijack the cells machinery to produce its own mRNAs (the code for making proteins) and then assemble these proteins (again by stealing resources from the host). Once many virions (the complete virus package) are formed, these form buds out the side of the cell and keep on infecting, replicating, spreading through the nerves leading to the brain.
Viruses are classified based on the way they store their genetic code (DNA or RNA). The virus that causes rabies is known as a negative-sense single-stranded RNA virus (or (-)ssRNA virus). Much like you, I am not sure on what all that means but I do have a point in including this information. The negative-sense single stranded RNA viruses are quite complex. The most interesting complexity I found is their ability to suppress the innate immune response of the cells it infects. Basically the virus not only infects and spreads in the host, but it also shuts down the immune system preventing the host from attempting to combat the disease, thus preventing the natural formation of antibodies in the immune system. Because of this, natural immunity is rarely found in humans, and humans could, in theory, contract rabies over and over again if the disease wasn’t almost always fatal in humans. With many other diseases our immune system is able to familiarize itself with a pathogen, either through vaccination or by contracting the disease, and is given a chance to fight the illness. Our immune system does this by developing specific antibodies for specific diseases. Our b memory cells then remember the pathogen that caused the disease as well as the antibodies that succeeded in defeating the disease. Our immune system is able to do this when exposed to the rabies through the vaccine because the vaccine consists of the inactivated virus, unlike when naturally exposed to the full rabies virus when infected. When exposed to the full virus, rabies shuts down our immune system before it begins to fight.
HOW CAN YOU CATCH RABIES?
The risk of infection is caused by a bite or scratch from an infected animal. The animal needn’t be alive to spread infection since it can spread from a dead animal. The virus is transmitted through saliva or brain/nervous system tissue. You can only become infected by coming into contact with these secretions and tissues. In the U.S rabies is no longer commonly found in dogs, cats, or livestock since most are now vaccinated. However, rabies or not, you should still seek medical treatment after a bite or scratch from any animal. Since about the 1960’s rabies in the U.S is most commonly found in wild animals. The wild animals most often reported to the Center for Disease Control and Prevention as having found to be infected with rabies are raccoons, skunks, and bats. Rabies is also reportedly found in foxes and other small rodents such as rabbits, though not as common as the previously listed wild animals.
In North and South America the most common wild animal to infect humans is the bat. Infected bats spreading the disease to humans is also becoming a rising concern in Europe and Australia. Asia and Africa see humans most often infected by dogs.
Although it has never been recorded or confirmed, human to human transmission by bite is theoretically possible. It is also possible, though extremely rare, for the virus to spread from human to human in aerosol form, such as a sneeze. Although still rare, the most common way humans spread rabies to other humans is through organ transplants when the disease goes undetected.
SIGNS AND SYMPTOMS
There are many symptoms of rabies and not every human or animal infected will experience all symptoms. However, there are a few signs that are almost always found in every case. In animals the most common symptoms are pica, fever, seizures, paralysis, hydrophobia, open or dropped jaw, inability to swallow, and change in demeanor. Change in demeanor is most commonly described as becoming agitated, or is most often recognized as excessive salivation and drooling. Some animals however, most commonly wild animals, have also been reported to behave oddly docile. This can manifest as no longer having a fear of humans or by showing a tame nature. Infected animals can often appear to be hallucinating and disoriented, sometimes acting drunk or in “dumb” form.
Same or similar symptoms found in animals are also regularly found in infected humans. The first symptoms to appear in humans often resemble the flu; symptoms such as fever, weakness and discomfort, and headache. These signs usually last a few days. The next symptoms are often itching at site of infection (bite), anxiety, confusion, and agitation. Next a person would see other forms of cerebral dysfunction such as delirium, odd behavior, insomnia, and hallucinations. They’d also exhibit difficulty swallowing, excessive salivation, hydrophobia, and paralysis.
Once symptoms appear in both animals and humans it is usually too late and survival is extremely rare.
HOW LONG BEFORE SYMPTOMS SHOW?
The incubation period (time from exposure to onset of symptoms) in both animals and humans may last for weeks to months. However, once this period is over and symptoms appear, it is often too late to seek effective treatment for the disease. This is why it is so important to seek medical attention during the incubation period, and since this time frame can vary without prediction it is best to seek treatment immediately after risk of exposure. During the incubation period, the disease spreads through the central nervous system until it reaches the brain. Once it has reached the brain and multiplied, symptoms will begin to show. The length of time it takes to do this can vary and is usually determined in part by the location of exposure (bite). The closer the bite or exposure is to the central nervous system, the shorter the incubation period will often be.
WHAT TO DO AFTER EXPOSURE
Once symptoms appear in a person, there aren’t any known treatments for rabies that are widely accepted or that carry much success. Death is almost always the outcome at this point. This is why it is so important to seek immediate medical treatment once bitten or scratched, or when risk of exposure is considered. Rabies can be prevented, and almost always is prevented when immediate treatment is sought.
Regardless of your possible risk of exposure to rabies, you should always seek treatment for an animal bite or scratch. Often times there can be nerve or tendon injury, or a risk of local and system infection. Once you seek treatment for a bite or scratch your doctor will determine your rabies risk factor. Deciding this risk factor will almost always err on the side of caution. If proof of a rabies vaccine for the animal that attacked you can be provided, then the risk is usually considered to be low or non existent. In which case it could be determined that there is no need for preventative measures. However, if the animal was wild, or if no proof of vaccination exists or can be found, then the risk is routinely believed to be considerable enough to administer preventative measures. These measures only vary slightly for most people. If the patient has never been vaccinated against rabies, which most of us in the U.S haven’t been, then the treatment should include both passive antibody, which is an immune globulin (HRIG) shot, and the vaccine. Those who have been previously vaccinated for rabies, or are receiving preexposure vaccination for rabies, should only receive the vaccine. Both treatment options are recommended regardless of time frame between possible exposure and seeking treatment. The vaccine should be given at recommended intervals that prove most safe and effective. It is important to show up for every scheduled interval to effectively avoid contracting rabies.
TREATMENTS ONCE INFECTED
Like I’ve made a point of stressing throughout this article, if you have been exposed to rabies, or even POSSIBLY been exposed to rabies, seek immediate medical treatment for the best chance of survival. If you fail to seek medical treatment before symptoms set in and you are in fact infected with rabies, then you should get your affairs in order since death is almost imminent.
There had been some hope in a treatment known as the Milwaukee Protocol or Wisconsin Protocol, named after the location in which it was first administered successfully. This course of treatment was developed and named by Dr. Rodney Willoughby in 2004 after a 15-year old girl was admitted to a Milwaukee hospital after a rabies diagnosis. After consultation with Centers for Disease Control and Prevention in Atlanta, the team assigned to the girl’s care formulated and implemented a new procedure. The procedure involved placing the girl in a drug-induced coma and given and an antiviral cocktail composed of ketamine, ribavirin, and amantadine. The theory considered that rabies pathology stems from central nervous system neurotransmitter dysfunction, so doctors hypothesized that suppressed brain activity would minimize damage while the patient’s immune system developed an adequate response. The patient survived, and was discharged 76 days later. This procedure seems to have worked. She did show some speech impairment and difficulty walking 131 days after discharge though it is unknown how long those conditions remained. Years later she was able to attend college, and remained the only successful case of the Milwaukee Protocol in the U.S. As of 2016 there have been 48 additional attempts to treat symptoms onset rabies with this method globally. These attempts have produced only 7 additional survivors. The Milwaukee Protocol for rabies is medicine’s version of a “Hail Mary” pass, only with less success. Because of this I’m going to say this again, if you’ve been exposed to rabies, or have a possible risk of exposure to rabies, seek immediate medical attention. If you fail to do so, and you end up contracting rabies, you almost certainly die.
CAN YOU DEVELOP NATURAL IMMUNITY?
While researching facts about rabies I found additional information that some readers may find interesting. I found it to be amazing. I considered writing about this in detail however that would take much more time and scientific understanding than I currently possess. Also, since this discovery does not alter the way any of us should approach a risk of rabies exposure, there’s no need to add it to the post here. However, I will provide a link and brief explanation. Scientists have discovered a group of Peruvians who are believed to have survived rabies exposure, and possible infection, without treatment or onset of symptoms. Blood taken from 63 people showed that 7 people were found to have “rabies virus neutralizing antibodies.” One of these seven received the vaccine previously, though the other six had not. The 6 individuals also reported to have been bitten by bats in the past, showing that rabies exposure is very possible to have happened. Normally, antibodies are only produced in humans who are vaccinated for the rabies virus. Scientists can only conclude that the six unvaccinated people who showed rabies antibodies must have been exposed to rabies and survived this exposure, and possibly even survived a rabies infection, suggesting their immune systems managed to build up a natural immunity to rabies. There is much more to this study and discovery! If you find this interesting I suggest you check out this link here to learn more.
Of all the diseases we face contracting, rabies is one that I take seriously. Rabies, and tetanus for that matter too, are two absolutely horrific ways one can suffer and then die. Both are also completely and easily preventable and should be prevented whenever exposure is possible. If you ever think you may have been exposed, or simply worry you could have been exposed, please contact your physician or seek urgent medical care immediately. DO NOT turn to Facebook groups for advice, and certainly refrain from taking the advice of anyone other than your medical care provider. Rabies