Rabies Hydrophobia
What is it?
Rabies is a severe viral infection of the brain that primarily affects animals. Raccoons, skunks, bats, foxes, and other mammals may be rabid; domestic dogs and cats can also become infected. Rabies may be transferred to humans through the saliva of an infected animal, usually by a bite, although the virus can also enter the bloodstream via a lick over broken skin. The rabies virus travels to the brain and attacks the central nervous system. Rabies is fatal in humans unless measures are taken right away to prevent the disease from developing, so if you are bitten by an animal, see a doctor immediately. Do not wait to see if rabies develops—once symptoms appear, the course of the disease is irreversible despite treatment, and death occurs within a few days. Symptoms most often emerge in four to eight weeks, but anywhere from 10 days to six months may lapse between the bite and the appearance of symptoms. Treatment consists of a series of vaccines and is effective only if administered in time.
What Causes It?
Rabies virus infection causes rabies.
Prevention
- Immunize pets against rabies. Human rabies is rare in the United States, thanks to extensive animalvaccination programs. Rabies in wild animals, such as raccoons, skunks, and bats, remains a problem.
- People at high risk (veterinarians and other animal handlers, hunters, cave explorers, and people planning to live in developing countries where rabies is prevalent) should get an annual rabies vaccine.
- Stray animals in areas where rabies is common are often killed by local authorities to prevent the spread of the disease.
- A quarantine is imposed on imported animals in countries where rabies is not present, including England, Japan, and Australia.
Diagnosis
- Patient history and physical examination.
- Biopsy of nerve tissue.
- Every effort should be made to capture the animal inflicting a bite so that its brain can be tested for the presence of the virus. Healthy-appearing domestic animals are kept under observation for 10 days to watch for any behavioral abnormalities.
How to Treat It
- Call a doctor immediately if bitten by an animal.
- Wash the wound gently but thoroughly with soap and water and then apply antiseptic.
- Immunization within two days of a bite usually halts the disease from developing. Two types of immunization are necessary: a passive immunization provides antibodies for immediate protection against the rabies virus; the active vaccine provokes the production of antiviral antibodies for long-term protection against the virus. The passive vaccine is injected around the wound as well as into a muscle. The active vaccine is given in a series of injections. People who have already received the active vaccine need only receive the passive one for treatment.
- Antibiotics and a tetanus booster shot may be given to prevent associated bacterial infections.
- Hospitalization is necessary if symptoms appear; however, the outlook is unfavorable at this point.
When to Call a Doctor
- EMERGENCY See a doctor immediately if you have been bitten by an animal; do not wait for symptoms of rabies to appear.
For more Johns Hopkins health information, please visit Johns Hopkins Health Alerts.
For medical appointments at Johns Hopkins, please call 866-386-1617.
All information contained within the Johns Hopkins Symptoms and Remedies website is intended for educational purposes only. Consumers should never disregard medical advice or delay in seeking it because of something they may have read on this website.
Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.