Follow new rabies guidelines, or you may overuse or misuse vaccines
November 1, 1999 5 minutes read
Follow new rabies guidelines, or you may overuse or misuse vaccines
Centers for Disease Control addresses post-exposure prophylaxis
When a patient arrives at the ED with a dog bite, your first instinct may be to give a rabies vaccine automatically. However, new guidelines published by the Atlanta-based Centers for Disease Control and Prevention (CDC) can impact the way you give a vaccine, and if you give the vaccine at all, notes Jean Proehl, RN, MN, CEN, CCRN, president of the Emergency Nurses Association in Des Plaines, IL.
The guidelines were developed by the CDC’s Advisory Committee on Immunization Practices to promote appropriate use of post-exposure prophylaxis (PEP) regimens, notes Charles Rupprecht, VMD, MS, PhD, chief of the CDC’s Rabies Section and director of the World Health Organization’s Collaborating Center for Reference and Research on Rabies, both based in Atlanta. (See excerpt, inserted in this issue. See source box, p. 2, for information on ordering full guidelines.)
"The last strategy over the previous decade under The Healthy Persons 2000 Program was not very successful," he reports. "It was striving to cut the absolute number of human rabies exposures in half by the year 2000."
This effort was made difficult by increases in animal rabies, lack of a reporting system, and hence, no surveillance. It was largely unsuccessful, says Rupprecht. "So, for the next decade, instead of attempting to reduce exposures in half, the new guidelines underline what is and what is not the appropriate use of PEP." (See related story, p. 4.)
Here is a summary of the changes in the new guidelines:
• The vaccine should not be injected into the gluteal muscle.
"There have been vaccine failures associated with gluteal administration," notes Proehl. In adults, use the deltoid site, she says. For children, the anterior or lateral thigh may be used.
Injecting vaccine into the gluteal muscle could possibly result in a human rabies case, warns Rupprecht. "When an exposure occurs, there are three things you want to do: Infiltrate immune globulin in and around the wound. Infiltrate vaccine into the muscle. But you don’t want it to go into adipose tissue. There have been cases where inoculation into such tissue is believed to have resulted in a human rabies case."
• Don’t overuse PEP.
Although approximately 100 people a day may undergo PEP on average, there have been no vaccine failures in the United States. "That’s because PEP is overused, so probably only a minority of people are ever truly at risk," says Rupprecht. "It also tells us how efficacious these current biologicals are."
However, in other parts of the world, when PEP guidelines have not been followed, human rabies has resulted. "Those usually entail situations when an exposure is recognized, but PEP is not used, or delayed, or used inappropriately," says Rupprecht. "Those are not situations we wish to have occur in the U.S."
PEP is expensive, so when it’s not indicated, large amounts of time and money are needlessly wasted, he maintains.
• Don’t delay vaccination.
"One of the major factors why vaccine failures happen are related to delays after exposure occurs and when the patient finally presents," notes Rupprecht.
Information sheets can help ensure that patients comply with necessary follow-up care after an animal bite. "Our ED uses a specific patient instruction sheet regarding animal bites at risk for rabies," reports Proehl. The form contains specific instructions for after care and when patients should come back to the ED.(See form for Animal Bite at Risk for Rabies, p. 3.)
• As much rabies immune globulin (RIG) as possible should be infiltrated into the wound.
The remaining RIG is given intramuscular (IM) in a different site than the vaccine, and the gluteals should not be used, says Proehl. "The previous recommendation was to infiltrate half into the wound and give half IM."
There was no scientific basis for that previous practice, stresses Rupprecht. "You are trying to get the RIG to the inoculated site where the rabies virus is, to supply virus neutralizing antibodies," he says. "If that’s the case, why would you ever be giving half and half? It was a rule of thumb without any substantiation, which may lead to a less-than-ideal response."
It’s sometimes not possible to give all the RIG in a single site, notes Rupprecht. "In that case, as much as possible should be infiltrated locally, and the remainder inoculated into an IM site," he says.
• Manage ferrets as other domestic pets.
Ferrets were not mentioned in the previous guidelines, notes Proehl. "In these guidelines, the direction is to manage them as you would a domestic dog in terms of surveillance and testing," she says.
• Vaccinate when patients are exposed to bats, even when there is no bite. Several cases of bat-associated human rabies have occurred in which there is no definitive bite or scratch, notes Proehl. "So, it is now recommended than anyone who has direct contact with a bat; any unattended child/developmentally delayed person found in a room with a bat; or anyone who awakes to find a bat in their room be vaccinated," she explains.
• Be aware that all vaccines currently approved are equally effective.
Four formulations of three rabies vaccines are approved for use in the United States. They include two forms of the human diploid cell vaccine, rabies vaccine adsorbed, and purified chick embryo cell vaccine. All types are considered equally safe and effective, according to the guidelines.
Only the Imovax rabies vaccine (human diploid cell vaccine, manufactured by Connaught Laboratories in Swiftwater, PA) has been approved by the Food and Drug Administration for the intradermal dose and route for pre-exposure vaccination. "We will stay with the vaccine that we currently are using [Imovax], unless a significant positive benefit is demonstrated from one of the other preparations," says Proehl.
• Submit form to CDC.
The CDC requests health care providers to submit a form for antemortem testing of human rabies cases. (See source box, p. 2, for information on obtaining a copy of the Possible Human Rabies — Patient Information Form.) This form is used for two primary reasons, notes Rupprecht:
1. The majority of cases are negative, and these data are useful for additional case discussion and differential diagnosis of open encephalitis cases.
2. If samples are positive, it provides important epidemiological information that is usually not provided on routine submission forms.
For more information about the new rabies guidelines, contact:
• Jean Proehl, RN, MN, CEN, CCRN, Dartmouth-Hitchcock Medical Center, Emergency Department, One Medical Center Drive, Lebanon, NH 03756. Telephone: (603) 650-6049. Fax: (603) 650-4516. E-mail: [email protected].
• Charles Rupprecht, VMD, MS, PhD, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G33, Atlanta, GA 30333. Telephone: (404) 639-1050. Fax: (404) 639-1058. E-mail: [email protected].
To obtain a copy of the complete text of the rabies guidelines or a copy of the Possible Human Rabies — Patient Information Form, contact:
• National Center for Infectious Disease, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, GA 30333. Telephone: (404) 639-1050. Fax: (404) 639-1058. Web: www.cdc.gov/ncidod/dvrd/rabies.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content