E-News Message from the CVMA Regarding Rabies

Periodically we receive news items from the Colorado Veterinary Medical Association. We would like to pass this one about the shortage of human rabies vaccine along to our readers.

HAN Advisory—Health Alert Network Broadcast

National Shortage of Rabies Vaccines

There are two rabies vaccines currently licensed for use in the United States: Imovax, a human diploid cell vaccine manufactured by Sanofi-Pasteur, and RabAvert, a purified chick embryo cell vaccine produced by Novartis. Novartis has limited supplies available and is only shipping vaccine in cases in which a patient has demonstrated severe allergic reaction to Imovax. They are expecting additional vaccine to be available sometime in July. Sanofi-Pasteur closed their production facility for renovation and is using a finite supply of vaccine they had stockpiled. They are currently distributing vaccine at a higher rate than historic levels and do not anticipate any additional production until their facility comes back on line sometime in 2009.

Currently, neither company is releasing any vaccine to health care providers (HCP) for pre-exposure prophylaxis. Sanofi is still supplying vaccine directly to HCP but if supplies continue to diminish, it may begin to require health department consultation and approval on a case-by-case basis prior to releasing vaccine. Therefore providers are urged to carefully evaluate patients to determine if post-exposure prophylaxis (PEP) is indicated according to the Advisory Committee for Immunization Practices (ACIP) recommendations. Additional updates are available at http://www.cdc.gov/rabies/.

Pre-Exposure Prophylaxis

• No vaccine is being released to medical providers for pre-exposure prophylaxis including travel immunizations.
• For persons with high risk of rabies exposure (lab workers, animal control officers, veterinary staff, wildlife biologists), physicians can request vaccine through the state health department. Requests are forwarded to the Centers for Disease Control where they are prioritized and vaccine shipped as it becomes available.
• Patients should be advised to be extra vigilant in avoiding rabies exposure by not petting, feeding, or handling animals while traveling; avoiding contact with wildlife; vaccinating pets; and other prevention strategies.

Post-Exposure Prophylaxis (PEP)

• Rabies PEP is a medical urgency not an emergency. PEP can be delayed pending tests result, efforts to locate the biting animal, or to obtain consultation on the need for treatment.
• The need for PEP depends on the species of the biting animal, prevalence of rabies in the area, circumstances of the bite, and availability of the animal for testing or observation.
• High-risk species in Colorado are bats and skunks. Raccoons, foxes and other wild carnivores represent a lower risk, but still would necessitate PEP if the animal were unavailable for testing.
• PEP is not indicated for rodent bites.
  
• Bites from herbivores (horses, cattle, deer, etc.) rarely would require PEP. The exception would be bites involving ill livestock from eastern Colorado.
• In most cases, dog and cat bites occurring in Colorado do NOT require PEP even when the biting animal is unavailable. The last case of indigenous rabies in a Colorado dog was 1974 and in a cat was 1985. There has been one case of imported rabies in a dog (2003) that represents the only rabid domestic pet in Colorado in the past 18 years.
• Dog and cat bites should be reported immediately to the local animal control agency so the biting animal can be quarantined for a 10-day observation period. Treatment should not be initiated when the biting animal is available for observation or likely can be located.
• PEP for bites from out-of-state dogs/cats or unlocated animals should be evaluated on a case-by-case basis.
• Consultation with the state health department is encouraged prior to initiating PEP and is available 24/7.

Rabies in Colorado

As noted above, rabies in domestic animals is extremely rare in Colorado. Bats have been the only endemic rabies host reported statewide over the past 30 years. On the eastern plains skunk rabies has been detected the past 2 years and ongoing surveillance is monitoring its spread. A rabies-positive coyote infected with skunk variant virus was confirmed last year in Prowers County. No endemic rabies transmission in terrestrial mammals has been documented in Front Range, Mountain, or Western Slope counties since the early 1970s. Eight sporadic cases of rabies in terrestrial mammals have been reported in the past 20 years as the result of spill-over infections from bats: 4 skunks, 2 fox, 1 bobcat, and the domestic cat from 1985. In addition to the imported rabid dog in 2003, two rabid cows were imported into the state during this period (1991, 2005).

Resources

• Guidance on rabies PEP is covered in Human Rabies Prevention – United States, 2008, Recommendations of the ACIP. This document can be accessed at: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr57e507a1.htm
• Colorado rabies statistics and policies can be found at: http://www.cdphe.state.co.us/dc/Zoonosis/rabies/index.html
• Consultation is available through your local health department or the Colorado Department of Public Health and Environment, Communicable Disease Epidemiology Program at 303.692.2700 (regular business hours) or 303.370.9395 (after hours, weekends, holidays).