Edward R. Rensimer, MD | Rabies Doc Houston

Rabies Overview:
Illness & Treatment

Edward R. Rensimer, MD | Rabies Doctor Houston | Immunizations, Rabies Treatment Plan, Rabid Animal Bite:Scratch, feral dog:cat, raccoon, bat, Rabies Exposure_photo1109331033.jpg

Rabies Overview

Rensimer and Associates is one of only a handful medical practices and organizations in Harris County where human rabies immune globulin(HRIG) and rabies vaccine, and the expertise to appropriately consider their use post-exposure to a possibly rabid animal or pre-exposure (occupational and travel) are available. Medical insurance payors are increasingly challenging payment for these services provided through hospital emergency rooms (and so hospitals are getting out of this business) because of the extreme charges for any ER visit since they do not consider this situation a legitimate medical emergency. Rabies immunization is usually a medical “urgency”, unless the animal contact is on the face or neck.

HRIG and rabies vaccine are stocked here and our organization is trained to operationally expedite their application, including evaluating to what extent medical insurers will cover their expense and what will be the patient’s financial obligation. Because we daily immunize to rabies (hundreds of individuals/year), it is highly unlikely an insurer will decline or otherwise contend with our position on the medical necessity of rabies immunization.

Most primary care professionals and emergency first-responders are preoccupied with medical conditions that are the more usual, high-traffic problems, and so they are not skilled at proper application of anti-rabies interventions or with the specifics of the disease. It is not uncommon for patients to get misinformation or to hit an information dead-end when presenting to PCPs and ERs.


·       Rabies is a viral infection that spreads through broken skin to the local nerves, and then to the brain and spinal cord. (encephalitis/myelitis)

·       Rabies is almost invariably fatal.

·       Rabies is mainly a disease of animals. Humans gets rabies when they are bitten, scratched, or licked with infected animal saliva.

·       At first there might not be any symptoms. But weeks, or even years (up to 19) after infectious contact, rabies can cause pain, fatigue, headaches, fever, irritability, and behavioral changes. These may be followed by seizures, hallucinations, and paralysis.

·       Wild animals, especially bats, are the most common source of human rabies infection in the United States. Skunks, raccoons, dogs, cats, coyotes, foxes, and other mammals, even livestock, can also transmit the disease.

·       Human rabies is rare in the United States. As of 2017, there have been only about 55 cases diagnosed since 1990. This is because we legally require vaccination of domestic animals and exposed individuals routinely receive post-exposure treatment by immunization.

·       Between 15,000 and 40,000 people are vaccinated each year as a precaution after animal bites.

·       Rabies is far more common in other parts of the world, with about 40,000 to 70,000 rabies-related deaths worldwide each year (outside the U.S., most commonly due to unvaccinated dogs and cats).

·       The average incubation period from contact with the virus to rabies disease is 2-8 weeks (range is 5 days to 19 years) and treatment to prevent it should be started as medically urgent, usually (seldom emergent).


Rabies is caused by a virus that lives inside some animals. When a person is bitten by an infected animal, the rabies virus is spread to the person through the infected saliva of the animal (not blood).

In the U.S., principal vectors are wild animals, especially bats, skunks, raccoons, coyotes, and foxes. Domesticated animals, like cats and dogs, can carry rabies, but are usually vaccinated against it (and so, usually unlikely a risk). Dogs are the major vector in foreign countries. Any unvaccinated or sick animal lick, bite, or scratch (claws), including from livestock and rodents, warrants medical evaluation.


By the time symptoms appear, rabies is virtually 100% fatal for the person. Common symptoms include:

  • Fever
  • Headache
  • Fatigue
  • Agitation
  • Anxiety
  • Confusion
  • Unusual behavior, such as hyperactivity, fear of water (hydrophobia), or fear of air (aerophobia)
  • Hallucinations
  • Insomnia
  • Weakness in the arms or legs
  • Difficulty swallowing
  • Pain or abnormal sensations near the bite site

Most people get sick within 3 months after physical contact. This often varies and may depend on the location of the bite. The clinical illness will take less time to emerge if the bite occurred closer to the head (and so, the brain).


To determine if a person is infected with rabies virus, several tests must be performed after symptoms and signs appear (too late for preventive measures to alter the course of disease),

  • Skin biopsy (rabies virus staining)
  • Saliva virus test
  • Lumbar puncture (spinal tap) to test spinal fluid for rabies virus
  • Blood tests

Note: There are no lab tests for rabies prior to onset of illness.


Post-rabies exposure treatment with injection of human rabies immunoglobulin (pooled human rabies antibody), called HRIG, and a 4-dose series of rabies vaccine is nearly 100% successful in preventing rabies infection.

If medical experts determine there has been a credible rabies exposure, treatment to prevent the infection from developing (post-exposure prophylaxis, PEP) should be started even before knowing for sure if the person has been truly exposed to the rabies virus (that is, if the contact animal, if available, has been shown positive for the virus).

PEP involves thoroughly cleaning the wound, giving some of the rabies antibody injection around the wound (rabies immune globulin), and starting a 4-dose series of rabies vaccine injections. The injections are usually completed over two-weeks.

If possible, the animal that contacted the person should be observed to see if it remains healthy (in which case, PEP may be withheld until the animal is cleared or becomes ill). For dogs, cats, and ferrets this is 10 days, if the animal appeared healthy and behaved appropriately at the time of contact. For other animals, the proper necessary observation period is unknown. If the animal has been killed, it can be sent to a state laboratory and examined to see if it had rabies (ask medical professionals or public health officials the safe, proper way to handle such an animal specimen); but, the tissues cannot be decomposed or such testing cannot be done.

If a person is bitten by a domestic animal (dog, cat, or ferret) that appears healthy and can be observed to see if it remains healthy, often no further treatment is necessary other than care of the wounds caused by the animal and possibly proactive antibiotics to head-off wound bacterial infection.

Rabies is almost always fatal once illness develops, although a few people with rabies have survived after experimental treatments. This is why medical professionals uniformly recommend PEP treatment for people who have been bitten, scratched, or salivated on by animals that are known to carry rabies virus. Rare rabies illness survivors do so with serious nervous system damage.


  • If you were bitten by an unfamiliar animal, make sure you know your rabies expert’s instructions for follow-up.
  • If the animal was sent to a laboratory for examination, ask when the test results will be ready.
  • Make sure you get the test results as soon as possible. You may be able to wait up to 10 days (to decide to start PEP) if it was a dog, cat, or ferret. With other animals, you may need to start PEP until test results are available; if negative for rabies, PEP can be stopped.

Take these steps to care for your wound:

  • Wash the wound thoroughly with soap and water for least 15 min., then with alcohol disinfectant, and then iodine (avoid any spray from the wound cleansing process entering the mouth, nose, or eyes). Any damaged tissue must be surgically debrided.
  • Keep the wound clean, dry, and dressed as directed by your physician.
  • Keep the injured part elevated as much as possible.
  • Ice the wound for the first several hours after contact, if practical.
  • Do not resume use of the affected area until directed.
  • Only take over-the-counter or prescription medicines as directed by your physician.
  • Keep all follow-up appointments as directed by your physician.


To minimize rabies risk, people need to reduce their risk of having contact with infected animals.

·       Make sure your pets (dogs, cats, ferrets) are vaccinated against rabies. Keep these vaccinations up-to-date as instructed by your veterinarian and in accordance with state and local laws.

·       Supervise your pets when they are outside. Keep them away from wild animals.

·       Call your local Animal Control services to report any stray animals. These animals may not be vaccinated.

·       Stay away from stray or wild animals.

·       Consider getting the rabies vaccine (preexposure) if you are traveling to an area where rabies is common (especially children) or if your job or activities involve possible contact with wild or stray animals. Discuss this with your physician.

·       Do not touch a wild, ill, wounded, or dead animal, and instruct your children on this; notify county Animal Control authorities of such animals.

Rabies Vaccine

What You Need to Know


  • Rabies vaccine can prevent rabies.
  • Rabies vaccine is given proactively to people at reasonable risk for rabies to protect them before actual exposure or after exposure as a preventive treatment.
  • Rabies vaccine is made from killed rabies virus. It cannot cause rabies.
  • Rabies “shots” are NOT a painful series given in the abdominal wall. They are usually given in the upper arm and the experience is identical to receiving a flu shot.


PRE-EXPOSURE VACCINATION (no specific exposure event)

  • People at high risk for exposure to rabies, such as veterinarians, animal handlers, rabies laboratory workers, spelunkers, and rabies biologics production workers should receive rabies vaccine.
  • International travelers who are likely to come in contact with animals in parts of the world where rabies is common and animal reservoirs are often not vaccinated; especially young children, who lack judgement.
  •  The pre-exposure schedule for rabies vaccination is 3 doses, given at the following times:
    • Dose 1
    • Dose 2: 7 Days after dose 1
    • Dose 3: 21 days or 28 days after dose 1
  • For laboratory workers and others who may be repeatedly exposed to rabies virus, periodic blood testing for enduring immunity (serum rabies antibody) is recommended and booster doses should be given as needed.


Anyone who has been bitten, scratched, or licked by an animal species known to transmit rabies (most warm-blooded animals), or who otherwise may have been exposed to rabies, should clean the wound or contact surface area of the skin thoroughly and contact a doctor who is an expert in rabies management immediately. The physician will determine if vaccination is needed.

Inexpert healthcare workers (such as emergency room physicians, nurse practitioners, physician assistants, and primary care physicians) and public health officials often give misleading or wrong advice about rabies. 

A person who is exposed and who has never been vaccinated against rabies should get 4 doses of rabies vaccine:

  • One dose right away and additional doses on the 3rd, 7th, and 14th days (those with impaired immune systems get a 5th dose on day 21 or 28).
  • They should also get another shot called Human Rabies Immune Globulin (HRIG, rabies antibody) at or about the same time as the first vaccine dose. (no later than 7 days after vaccine dose 1)

A person who has been previously vaccinated and who has suffered rabies exposure should get 2 doses of rabies vaccine: one right away and another on the 3rd day. HRIG is not needed. (unless the individual has an immune system weakened by disease or medical treatments)


Talk with a doctor before getting rabies vaccine if you:

  • Ever had a serious (life-threatening) allergic reaction to a previous dose of rabies vaccine or to any component of the vaccine; tell the physician if you have any severe allergies.
  • Have a weakened immune system because of: *
    • HIV/AIDS, or other diseases that affect the immune system.
    • Treatment with drugs that affect the immune system.
    • Cancer or cancer treatment with radiation or chemotherapy.

 * If your immune system is impaired, you may need an extra vaccine dose(s), as determined by rabies antibody measured in the blood 2-4 weeks after the last dose of the routine series.

  • If you have a minor illness, such as a cold, you can be vaccinated.
  • If you are moderately or severely ill, you should probably wait until you recover before getting a routine pre-exposure, preventive (non-exposure) dose of rabies vaccine, although the decision to delay vaccination must be made by an experienced rabies specialist.
  • If you have been exposed to rabies virus, you should get the vaccine, regardless of any other illnesses you may have or pregnancy.
  • With a legitimate exposure to rabies, there is no contraindication to the vaccine or HRIG since infection is fatal and horrific.


A vaccine, like any medicinal, is capable of causing serious problems, such as severe allergic reactions. The risk of a vaccine causing serious harm, or death, is extremely small. Serious problems from rabies vaccine are very rare.

Anything that might adversely result from the rabies vaccine or HRIG pales in significance compared to rabies disease. Therefore, any reaction or problem related to HRIG or the vaccine, regardless of severity, must be managed rather than stopping the rabies prevention protocol since rabies is virtually uniformly fatal.

Mild problems:

  • Soreness, redness, swelling, or itching where the shot was given (30% to 74%)
  • Headache, nausea, abdominal pain, muscle aches, or dizziness (5% to 40%)

Moderate problems:

  • Hives, pain in the joints, or fever (about 6% of booster doses)
  • As with other vaccines, nervous system disorders, such as Guillain-Barré syndrome (polyneuritis), have been reported after rabies vaccine, but these happen so rarely that it is not known whether they are causally related to the vaccine.


What should I look for?

Look for anything unusual, such as signs of a severe allergic reaction, very high fever, or behavioral changes.

Signs of a severe allergic reaction can include hives, swelling of the face and throat, difficulty breathing, rapid heartbeats, dizziness, and weakness. These would start a few minutes to a few hours after the vaccination.

What should I do?

  • If you think it is a severe allergic reaction or other emergency that cannot wait, call 911 or go to the nearest hospital Emergency Department or emergency facility.

  • Call your doctor on the way there or after you arrive.

  • Afterwards, the reaction should be reported to the Vaccine Adverse Event Reporting System (VAERS). Your doctor might file this report, or you can do it yourself through the VAERS website at ww.vaers.hhs.gov or by calling 1-800-822-7967.

VAERS is only for reporting reactions. They do not give medical advice.