Where Do I Start?
If you are reading this, you likely are concerned that you or a loved one has been exposed to the rabies virus. I will not reiterate the basic science of the virus, animal reservoir/vectors, modes of transmission, disease manifestations and course, prognosis, and preventive options. All that information is easily obtained by Internet search – try cdc.gov or another of our websites: www.traveldoc.com for more information on rabies.
Instead, as one of the very few sites providing comprehensive rabies risk analysis and preventive services in Harris County (cases are referred to us by the U.S. Centers for Disease Control, Atlanta, GA and Harris County Animal Control/Public Health), I want to give distilled information that is of most use in guiding your immediate actions and allaying your anxiety. This information should serve as an operational primer so you can quickly do the right thing.
The most common source animal in the U.S. is bats. Most dogs and cats are domesticated and vaccinated, so not as subject to carrying the virus. Outside the U.S., dogs and cats most commonly cause human rabies.
IMPORTANT: The key issue with such common animals is whether the owner is known and whether the animal’s rabies vaccination status is up to date, or whether the animal can be kept in observation for 10 days after the contact.
Recently, the CDC made it clear that feral cats can be a source.
Key Action Items
- Contain and quarantine an animal that bit or scratched you. If the animal behaves normally (not sick, behaving atypically, or dead) after 10 days from your contact, you are ok (no further action needed).
- Wear rubber or plastic gloves and collect the bat or animal carcass in a container or plastic bag and take it to the Harris County Animal Control or call them or your local county officials to pick it up. If off-hours or weekend, ice or refrigerate it. The specimen can be autopsied and brain tissue studied for rabies virus (if not too decomposed). If negative, you are ok.
- An exception to the 10-days observation period may be if a bite/scratch is very close to your brain, such as on the face (in this case, you will need to consult with an expert).
- The most immediate effective rabies prevention action is to thoroughly and aggressively clean an animal bite/scratch with soap and water to wash-out the tissues completely – for at least 10 minutes. Clean out any debris, tissue fragments, or tissue that appears devitalized.
- If you had been in a state of diminished consciousness or awareness (sleep, intoxication, etc) and subsequently find a bat sharing your space, you are at risk. There have been fatal rabies cases with nothing more than that story and no apparent bite or scratch marks on the victim. Physical bat contact while impaired/asleep is presumed. Likewise, if the exposed person is a child, you will need to weigh the reliability of their story on whether or not they had contact with a bat. Unless you are certain there could not have been contact, rabies immune prophylaxis is indicated.
Rabies Post-Exposure Intervention
- We “over treat” for rabies exposure. There is no doubt that very few encounters with risky animals will result in human rabies. However, since cases of survival are only a few and there is no established effective treatment, it is considered a virtually fatal disease. We do not approach this hoping you are lucky.
- Rabies vaccine is safe (very small chance of any serious adverse effects); the disease is deadly, but the vaccine is no more worrisome than any other standard vaccine, such as that for tetanus.
- Rabies vaccine is effective. Given along with human rabies immune globulin (HRIG) it prevents the disease, if given timely.Because rabies immunization is an unique situation of relying upon this intervention as de facto treatment for a fatal disease and most patients presenting with this problem have no idea of the adequacy of their immune system, we check the vaccine’s performance in each case by checking the blood for adequate levels of protective rabies antibody some weeks after the final dose. This is not standard practice, but we believe it should be. All vaccines have variable efficacy – in this case, there is no room for failure.
- Rabies vaccine is given in a 4-dose series. Despite “urban legend” rumors, it is not a series of extraordinarily painful shots in the belly. The HRIG dose is weight-based and as such results in a significant volume of fluid with the consistency of syrup, deep in the muscle – and so, far from pleasant. But, it is only given once.The rabies vaccine injection experience is identical to a “flu” shot.
- Rabies exposure is a medical urgency, but not usually emergency, since it takes days – months for the virus to travel from the wound entry to the brain (cases as long as 8 years have been recorded).For this reason, fewer and fewer hospital Emergency Departments or Urgent Care Centers are stocking HRIG and vaccine – insurers want to discourage patients from seeking and receiving non-emergent rabies preventive services there with the huge ER facility charges. The insurer may contend with paying for rabies vaccine and HRIG given in emergency centers; even decline to do so.
- Insurers will generally cover the HRIG and vaccine for legitimate post-exposure risk, but not for pre-exposure prevention, such as for animal handling occupations and risky travel.However, medical insurers do not determine medical necessity for HRIG and vaccine, only their willingness to pay for it. Only a physician with expertise in these matters can diagnose and treat, and so are qualified to determine medical necessity. The physician who recommends rabies preventive intervention will do so regardless of the source of payment for the services.
Although, you may have many more questions, this should provide enough information to take appropriate, timely action. The biggest problem is the lack of information in the general medical community about what to do with rabies exposure cases and where to get services.
Feel free to call us: 713-973-6078.
For more specific information on rabies disease, vaccination, or HRIG, please visit our website: www.traveldoc.com
Edward R. Rensimer, MD, FACP