Rabies is a viral infection of the brain. It is typically contracted from the bite of an infected animal. In the U.S., the illness is exceedingly rare but often deadly. In an April 2010 article published by the Centers for Disease Control and Prevention, Dr. J. House and colleagues reported 31 cases of human rabies occurred in the U.S. from 2000 through 2009. Rabies has a long incubation period followed by an early stage of the illness, which precedes the development of nervous system symptoms. Recognizing early stage rabies may provide an opportunity for life-saving medical intervention.
Fever and Chills
The development of fever, chills and other flu-like symptoms indicate the onset of early stage rabies. Early stage rabies is preceded by an incubation period of 20 to 90 days after the infectious bite. During this symptom-free period, the rabies virus migrates from the site of infection (the bite wound) to the brain through the nerves.
Loss of Appetite, Nausea and Vomiting
Early-stage rabies typically causes loss of appetite, nausea and vomiting. Abdominal pain may also occur, although it is not a prominent feature of this stage of the illness.
Headache
Headache is a common symptom of early stage rabies. The headache typically persists throughout the illness.
Sore Throat and Cough
Sore throat and cough may develop during early stage rabies, although these symptoms are not uniformly present in all people with the illness.
Lethargy and Malaise
Early-stage rabies causes an overall sense of unwellness known as malaise. This typically progresses to lethargy, a state of mental dullness and sluggishness. The development of lethargy typically heralds the impending onset of late stage rabies with full-blown brain involvement. Once brain-related symptoms develop, rabies is usually fatal.
Pain or Abnormal Sensations at the Site of the Bite
The only distinctive symptom of early stage rabies that can help distinguish it from a simple flu-like illness is the presence of pain, itching, burning or tingling at the site of the animal bite. When this symptom is present, it is an ominous sign the disease is moving into the late stage. According to the CDC, the time from the first symptom of early-stage rabies to late stage disease is typically two to 10 days.
References
- Centers for Disease Control and Prevention: Rabies
- Centers for Disease Control and Prevention: What Are The Signs and Symptoms of Rabies?
- Centers for Disease Control and Prevention: Path of the Rabies Virus
- Centers for Disease Control and Prevention: Rabies Information for Doctors
- Centers for Disease Control and Prevention, MMWR: Human Rabies--Kentucky/Indiana, 2009
