Condition. Rabies

What is rabies in humans?

Rabies is a potentially deadly virus. It can be spread to humans through a bite from the saliva of an infected animal. In the United States, animals most often carrying rabies virus and transmitting the disease to humans include: 

• skunks
• coyotes
• bats
• foxes
• raccoons

In the developing countries of Southeast Asia and Africa, rabies is most commonly spread to people by stray dogs. Those at risk for contracting the virus should get a vaccine to protect themselves. If the affected person starts showing signs and symptoms of rabies, virus infection almost always leads to death.

Rabies causes

Rabies virus causes rabies infection. The virus is carried and spread by the saliva of infected animals. For example, it can be transmitted by an infected animal biting another animal or biting a human. Occasionally, the rabies virus can be transmitted when infected saliva enters the eyes or mouth (mucous membranes). For example, this might happen if an animal with signs of rabies licked an open sore or cut on a person’s skin. For a human to get rabies, two things must happen: 

1. the person should have contact with a rabid animal
2. during the contact, the transmission of infected material should occur, including exposure to the spit of the rabid animal from a bite or scratch

Mechanisms of infection transmission

• Bites from rabid animals are the most widely recognized method of transmitting rabies to humans.
• Scratches by rabid animals are less likely to cause the disease than bites, yet are still considered a potential method of rabies transmission.

Among the infected tissues in rabid animals is spit. The virus is transmitted when infected material gets into bite wounds, open cuts on the skin caused by scratches, or onto mucous membranes. At that point, the infection spreads from the site of introduction to the brain, then all through your body’s significant organs.

Rabies can get into humans through organ and tissue transplants in rare situations. 

What animals can transmit the rabies virus?

Any mammal can spread the rabies virus. However, animals most likely to transmit rabies to humans are: 

Farm animals and pets

• Dogs
• Cats
• Cows
• Ferrets
• Horses
• Goats

Wild animals

• Beavers
• Bats
• Coyotes
• Monkeys
• Foxes
• Skunks
• Raccoons
• Woodchucks

Prevalence

Every year, researchers from the Centers for Disease Control and Prevention (CDC) gather data about instances of rabies in humans and animals from the state health divisions and distribute the data in an outlined report. In 2015, 50 states and Puerto Rico reported 5,508 instances of rabies in animals and three cases in humans to the CDC. This number of announced cases decreased by 8.7 percent compared to 2014 (6,033 animals and one human instance of rabies). Wild creatures represented 92.4 percent of cases of rabies in 2015. Bats were the most out of control natural life species (30.9 percent of animal cases in 2015), trailed by raccoons (29.4 percent), skunks (24.8 percent), and foxes (5.9 percent). Household animals represented 7.6 percent of every out-of-control animal announced in the United States in 2015. The number of announced rabid dogs increased in 2015 as opposed to 2014. However, the number of revealed rabid cats diminished from 272 in 2014 to 244 in 2015. In addition, the number of rabid cows in 2015 expanded contrasted with 2014, while the number of rabid horses and donkeys decreased. During this century, in the United States, human deaths caused by rabies have declined from at least 100 every year to 2-3. Two projects have been in charge of this decrease. Firstly, animal control and immunization programs started in the 1940s, and oral rabies vaccination programs in the 2000s have eliminated domestic dogs as a reservoir of rabies in the United States. Secondly, viable human rabies vaccines and immunoglobulins have been produced.

Rabies risk factors

Certain factors can increase the risk of contracting the rabies virus. These include: 

• Living in or traveling to developing countries in which rabies is more common. The list includes countries in Southeast Asia and Africa.
• Participating in activities where you may come in contact with animals that often carry the rabies virus. Such activities may include camping without taking safety precautions to keep animals away from your campsite or exploring dark caves where bats like to live.
• Working at a job requiring you to handle the virus (in a laboratory).
• Wounds on the neck, hands, or head. These allow the virus to spread more rapidly to the brain.

Complications

As with any disease, rabies has some complications. They include: 

• the constant pressure inside the skull (intracranial pressure)
• irregular heartbeats (cardiac arrhythmias)
• respiratory failure
• seizures
• acute renal failure
• heart failure
• gastrointestinal hemorrhage
• coma

In some cases, paralysis occurs at the early onset of signs of rabies. 

You can learn about symptoms of rabies in humans by Clicking Here.