Pet owners know their companions get a rabies vaccination at the vet, but how much do you really know about the disease?
Rabies is a viral disease of mammals that infects the central nervous system. It travels directly to the brain and causes death. While deadly, rabies is a preventable disease. In the United States it is rare for humans to contract rabies, only about 3 or 4 cases a year. But in other countries, “ Around 59,000 people die from rabies every year, according to a 2015 study published in PLOS Neglected Tropical Diseases. The overwhelming majority are in Asia and Africa.” (CDC) A startling fact is that “40% of people who are bitten by suspect rabid animals are children under 15 years of age.” (WHO)
In the U.S., even though the number of humans infected has been dramatically reduced, the threat remains very real. The CDC said. “During 2014, 50 states and Puerto Rico reported 6,033 cases of rabies in animals and 1 human rabies case to CDC.” More than 90% of the animals reported to be rabid are in the wild. The top four animals are raccoons, bats, skunks, and foxes. Rabid bats or domestic dogs and cats that have been bitten by an infected wild animal pose the greatest risk for humans in the U.S.
Surprisingly, the CDC reported four times as many rabid cats than dogs in 2014 in the U.S. Not as many cat owners are taking their cats to a Veterinarian for the vaccination and this compounds the threat when the unvaccinated cat is let outside where it can more easily come in contact with an infected wild animal. Something else to consider is that bat bites are so tiny they are commonly missed on humans yet alone under a layer of fur.
The way the rabies virus is transmitted is most commonly through saliva but it can also be from contact with brain/nervous tissue. If bitten, the most effective way to decrease the chance for infection is to wash the area with soap and water thoroughly and promptly follow up with a doctor. If your doctor thinks there is a risk, or the animal is confirmed to have rabies, you will need a series of vaccinations called postexposure prophylaxis or PEP. With proper wound care and PEP, death is almost entirely avoidable. Early symptoms are flu like so it can be difficult to tell something serious is wrong. There are more specific symptoms that appear as the disease progresses such as, confusion, insomnia, anxiety, hallucinations, some paralysis, hypersalivation, difficulty swallowing, agitation, and fear of water. But once these symptoms present, the disease is too advanced and death is imminent, usually with days.
Rabies is a very old disease even dating back to ancient Egypt. One would think that today we would be able to control, if not eliminate, this dread disease. However, the poorer the area, the higher the risk or exposure to rabies (unvaccinated stray dogs) and the less they have access to treatments. The World Health Organization says that, “Vaccinating dogs is the most cost-effective strategy for preventing rabies in people. Dog vaccination will drive down not only deaths attributable to people but also the need for PEP as part of dog bite patient care.”
Raccoons, bats, skunks, foxes, and coyotes are the reservoir animals that carry rabies. They can bite/scratch other mammals that then are infected and can turn around and infect others, such as cats and dogs.
The most frequent way rabies is transmitted is though the saliva during a bite that punctures the skin. A scratch that breaks the skin can also be considered a potential threat as saliva could possibly have been on the claw. Transplants of infected organs or corneas are the only human-to-human documented cases. You cannot get rabies from petting an animal, being licked by an animal, drinking the animal’s milk, or coming in contact with its blood, urine or feces. Preparing or eating raw meat is high risk since you could be exposed to nervous bodily tissue. Just because you have been bitten or scratched by an animal doesn’t always mean that animal has rabies. But if the animal is wild or acting strangely, seek medical attention. Studies have shown that the disease has been found in animal’s saliva several days before the animal exhibits signs of infection. Dogs are often transmitters due to our closeness with them.
There is an incubation period for rabies that can vary greatly. Typically it is between 1 and 3 months, but it can be anywhere from 1 week to 1 year. There have even been cases where it was even years. There can be a fever and pain or tingling around the wound site. The virus will then travel through the nervous system where the fatal inflammation of the spinal cord and brain occur. There are two different forms of the disease that present next. Most often it is furious rabies. This form has hyperactivity, excitability, fear of water, and sometimes fear of flying. Death is days away once these symptom show. Paralytic rabies is the other form and occurs in 30% of human rabies cases. Here, the muscles become paralyzed around the wound site and then a coma follows. It is more drawn out before death occurs and is often misdiagnosed. There is no test to confirm clinical rabies before the fatal symptoms show. That is why thorough wound cleansing and PEP are so important after a bite that cannot be proven to not be a rabid animal.
PEP – Post Exposure Prophylaxis
The rabies PEP is a dose of the human rabies immune globulin (HRIG) and rabies vaccine given immediately. Then, the vaccine is given again routinely on days 3, 7, and 14. Even if treatment did not start immediately after exposure, this protocol is the same. If someone has already received a preexposure vaccine, then they would just receive the vaccine and not the HRIG
People being treated with PEP are not contagious to others and can go about their daily routine. If the virus reaches the nervous system, a person would be contagious through saliva, nervous bodily tissue and possibly sexual contact. PEP is successful because it prevents the virus from reaching the nervous system.
If a human is bitten, it is best to be able to observe the animal and have it tested if necessary.
In Ohio, if a domestic dog bites someone, the dog needs to be under observation for 10 days to make sure they do not exhibit signs of rabies. After that you may not have to have the PEP treatments. If you cannot observe the animal your doctor may want PEP treatments since dying is the only outcome. ???
If your pet or livestock are unvaccinated and bitten by a wild mammal that couldn’t be caught, the CDC recommends euthanasia. If the owner chooses not to euthanize, it’s 6 months strict isolation and a vaccination 1 month before release. If your animal has an expired vaccination, they should be evaluated case by case. And if your animal has an up to date vaccination, it’s a 45-day observation.
When an animal is tested for rabies, the test looks for rabies virus antigens in brain tissue. This means if an animal is suspected to have rabies, its head is removed and sent for testing to get the brain tissue.
Rabies Prevention in your pets the CDC says to:
“First, visit your veterinarian with your pet on a regular basis and keep rabies vaccinations up-to-date for all cats, ferrets, and dogs.
Second, maintain control of your pets by keeping cats and ferrets indoors and keeping dogs under direct supervision.
Third, spay or neuter your pets to help reduce the number of unwanted pets that may not be properly cared for or vaccinated regularly.
Finally, call animal control to remove all stray animals from your neighborhood since these animals may be unvaccinated or ill.”
If a 100% fatal virus that causes terrifying neurological symptoms isn’t scary enough, an article from the New Mexico Department of Health on May 19, 2015 reported, “The New Mexico Department of Health (NMDOH) announced today that a rabid fox from Lincoln County that bit a woman on April 20 had a strain of rabies that has never before been identified. The genetic sequencing of the virus was done in the Rabies Laboratory at the Centers for Disease Control and Prevention (CDC) in Atlanta. The woman received a series of rabies vaccinations that has prevented her from developing rabies, which is usually fatal.” So while the treatment saved this woman, the virus can change.
Rabies is truly a horrific disease. About 40,000 Americans go through the PEP treatment for it every year. (CDC) The decline in the number of human deaths in the U.S. from rabies since the 1970’s is directly contributed to “due to animal control and vaccination programs, modern rabies biologics following exposure, and successful outreach campaigns.” (CDC) This is a challenge in some other areas of the world since a successful campaign against rabies requires coordination of both animal and human health sectors. With perseverance and collaboration, we can continue to find a way to treat and reduce the prevalence of this virus.
Rabies, Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 2016. Web. 29 Sept. 2016.
By Enabling the Implementation of Proven Control Strategies, These Create Sustainable Rabies Elimination Programs and Could Ideally Be Expanded to Neighbouring Regions and Countries. “Rabies.” World Health Organization. World Health Organization, n.d. Web. 29 Sept. 2016.
“Human Rabies.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 2015. Web. 29 Sept. 2016.
“Rabid Fox from Lincoln County Has New Rabies Strain.” Rabid Fox from Lincoln County Has New Rabies Strain. N.p., 19 May 2015. Web. 29 Sept. 2016.