Animal Bites

ALSO KNOWN AS

Also see Rabies

DESCRIPTION

* An infection that affects the central nervous system (brain, spinal cord, and cranial nerves) of animals and humans

SYMPTOMS

* Symptoms may develop 30-50 days after the bite.
* Often there is only pain and local swelling at the bite site.
* Fever
* Headache
* Numbness or tingling at the bite site
* Swallowing difficulty
* Anxiety and restlessness
* Declining mental function
* Sore throat
* Nausea
* Muscle stiffness
* Excessive salivation (not real foaming at the mouth, but increased saliva)
* Itching at the site of the bite
* Muscle Cramps
* Tingling and numbness of the skin in other parts of the body
* Paralysis of muscles including respiratory muscles (breathing)
* In severe cases:

1. Hydrophobia -- fear of water because liquids can cause spasm in the throat and make swallowing difficult
2. Aerophobia -- in some, air can also trigger spasm in the respiratory (breathing) muscles
3. Excitement and agitation followed by periods of calm
4. Drooling
5. Gasping for air
6. Convulsions, Seizures, Coma, and death
7. Death occurs due to heart or respiratory failure
8. Only 7 people worldwide have been known to survive untreated Rabies (i.e., did not receive the series vaccination for Rabies after being bitten or exposed to a rabid animal).

CAUSE

* Virus -- RNA virus is transmitted via the saliva of the infected animal.
* The virus in the saliva enters a wound (after a bite) or skin cut, and travels via the nerves to the central nervous system, where it can multiply in the gray matter of the brain. Then the virus spreads out along certain nerves to infect many other tissues.

* The time between the bite and the onset of symptoms (incubation period) may range from days to years, but in most cases it is between 3-12 weeks.

HOW THE DIAGNOSIS IS MADE

* History of the bite, occupation, illnesses, travels, allergies, surgeries, habits, and vaccination history of the patient (i.e., Rabies, Tetanus, etc.) and his pets are helpful.
* Medical exam will reveal:

1. Bite mark
2. Fever
3. Agitation
4. Numbness
5. Paralysis

* Tests:

1. The virus needs to be found in the saliva or brain tissues, including the spinal fluid (CSF).
2. Fluorescent antibody (protein associated with Rabies) test will be positive in the infected animal.
3. The rabid animal should be captured if possible, terminated, and tested for the virus.

RISK FACTORS

* Animal bite from wild or unvaccinated pets
* All warm-blooded animals (Mammals) can carry the virus.
* Bats (most common in the US), dogs, cats, foxes, raccoons, and skunks
* Veterinarians
* Laboratory workers
* Animal handlers
* Travel to areas with high rate of Rabies in animals

TREATMENT

* Clean the wound
* Support the blood pressure, breathing, and heart if affected
* Immunoglobulins (HRIG) are protective Proteins that are given right away to fight the infection.
* The patient receives a vaccine to develop his or her own protective immunoglobulins down the road. Vaccines can be any of the following (HDCV, RVA, and PCEC).
* Report to the doctor if you have allergies, especially to eggs.
* In those who have been vaccinated prior to exposure, two booster shots (to provide more protection) of the vaccine are recommended.
* Tetanus vaccine, if not updated, is often given.

IF YOU SUSPECT THIS CONDITION

* Get to your doctor as soon as you can. If there is difficulty breathing, Seizures, confusion, or Coma -- call 911.

PREVENTION

* Vaccinate your pets -- dogs need Rabies vaccinations every 2 years, especially in areas with wild animals.
* Avoid contact with wild animals
(e. g., feeding, petting, etc.).
* If bitten, wash the site with soap and water and contact your physician and local health department immediately. Delay in treatment can result in death. Treatment after the bite from an animal with Rabies is with the Rabies vaccination series, which must begin soon after the rabid bite.
* Vector control and contact your doctor
* If traveling to an area known for Rabies, you must receive a vaccine (HDCV, RVA, and PCEC) before leaving. Vaccination is important for high-risk occupations.

SIMILAR CONDITIONS

* Other Infections:

1. Encephalitis
2. Tetanus
3. Guillain-Barre Syndrome