Skip Navigation LinksSkip Navigation Links
Centers for Disease Control and Prevention
Safer Healthier People
Blue White
Blue White
bottom curve
CDC Home Search Health Topics A-Z spacer spacer
Blue curve MMWR spacer

An Imported Case of Rabies in an Immunized Dog

On November 7, 1986, rabies was diagnosed in a dog euthanized November 4th in a Westchester County, New York, animal hospital. For years, Westchester County has reported rabies only in bats.

The dog, a mixed Rhodesian Ridgeback, was acquired in December 1983 in Bamenda, Cameroon, by the owners, Americans living in West Africa. The dog had been regularly vaccinated against rabies. It had received its first inactivated rabies vaccine in February 1984, when it was 10 to 12 weeks old. A second dose was administered 1 year later. The dog arrived in the United States on January 16, 1986, and received a third dose of inactivated rabies vaccine in early March. The dog had not been bitten by any animal after its arrival in the United States. The owner reported, however, that just before leaving Cameroon on January 14, 1986, the dog had been scratched by a stray dog in a hotel lobby in Douala, Cameroon. The wound was cleaned thoroughly, but no rabies vaccine was administered at that time.

On October 3l, l986, the owner, a school teacher in Yonkers, New York, brought the dog to school with her. Two students were exposed to the dog's saliva, and fifteen other students and a teacher had minor contact with the dog. That afternoon, the dog was noted to have paralysis of the lower jaw and was taken to a local animal hospital. The dog was ambulant, remained docile, and did not exhibit any furious signs. It was discharged with a diagnosis of a "viral infection", and instructions were given to force-feed it. The dog was again seen in the clinic the morning of November l, but because of deteriorating neurologic conditions was taken to a second animal clinic on November 2. It was kept overnight and discharged November 3. That evening the dog was returned to the first animal hospital and was euthanized the next day. Direct flourescent antibody testing and isolation of the virus in neuroblastoma cells at the New York State Health Department confirmed the diagnosis of rabies. Analysis by monoclonal antibodies (1,2) indicated that the virus differed from strains isolated from bats or terrestrial wildlife in the United States. It was, however, identical to rabies strains isolated in West Africa, a finding that suggested the dog had acquired rabies there.

A total of 37 individuals received post-exposure prophylaxis for possible exposure to the dog during its illness and the 2-week period prior to onset. This included the dog's owner, the veterinarians and their assistants, four neighbors, 17 students, and a teacher. Reported by E Argentina, B Bowman, AS Curran, MD, K Farrell, F Guido, GN Haloukas, MM Landrigan, BO Mojica, MD, FR Morrissey, C Ryan, VO Sousa, MD, F Virtuoso, Westchester County Dept of Health, C Trimarchi, R Gallo, B Rudd, D Morse, MD, State Epidemiologist, New York State Dept of Health; Viral and Rickettsial Zoonoses Br, Div of Viral Diseases, Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: Dog rabies is endemic in most of Africa, Asia, and Latin America (3). In the United States, however, dog rabies has decreased dramatically, from 5,688 cases in l953 to 113 in 1985. Wildlife rabies, on the other hand, has increased considerably and accounts for 91% of all reported cases; the main reservoirs are skunks, raccoons, and bats (4). Epidemiologic studies (5) and monoclonal antibody analysis (1,2) have shown that dogs in the United States are usually infected by rabid terrestrial wildlife species.

Current Public Health Service quarantine regulations (6,7) require that all dogs imported from countries with endemic rabies have a valid certificate of rabies vaccination and be vaccinated against rabies at least 30 days prior to entering the United States. These requirements were fulfilled for this dog since it was vaccinated twice with an inactivated vaccine that normally gives a 3-year immunity.

Rabies must be suspected when dogs imported from rabies-endemic areas develop unexplained neurological disease, even if the dogs have been vaccinated. The 9H-month incubation period reported here is very rare (8,9,10), although a few cases with incubation periods 6 months have been reported in dogs released from quarantine in the United Kingdom (8,9). In addition, vaccine failures such as the one described here are uncommon (10) and represent only 4% to 6% of reported cases in the United States for 1971-1973 (5). Failures following the administration of inactivated rabies vaccines may result from an incomplete immunization schedule, poor handling of the vaccine, or inadequate immunologic response (11). Regarding vaccine potency, the three vaccine lots from which this dog was vaccinated had been tested and shown potent by the manufacturers and national testing agencies.


  1. Smith JS, Sumner JW, Roumillat LF, Baer GM, Winkler WG. Antigenic characteristics of isolates associated with a new epizootic of raccoon rabies in the United States. J Infect Dis 1984;149:769-74.

  2. Smith JS, Reid-Sanden FL, Roumillat LF, Trimarchi C, Clark K, Baer GM, Winkler WG. Demonstration of antigenic variation among rabies virus isolates by using monoclonal antibodies to nucleocapsid proteins. J Clin Microbiol 1986;24:573-80.

  3. Acha PN, Arambulo PV III. Rabies in the tropics: history and current status. In: Kuwert E, ed. Rabies in the tropics. Berlin: Springer-Verlag, 1985:343-59.

  4. CDC. Rabies surveillance annual summary, 1985. Atlanta, Georgia: US Department of Health and Human Services, Public Health Service, 1986.

  5. Kappus KD. Canine rabies in the United States, 1971-1973: study of reported cases with reference to vaccination history. Am J Epidemiol 1976;103:242-9.

  6. Public Health Service. Importations: dogs and cats. Federal Register 1986;42(1):54-6.

  7. CDC. Compendium of animal rabies control, 1987--prepared by: the National Association of State Public Health Veterinarians, Inc. MMWR 1987;35:807-10, 815-8.

  8. Kaplan MM. The epidemiology of a fickle virus. Proc Roy Soc Med 1971;64:225-8.

  9. Turner T. The risks and problems associated with the importation of dogs, cats and other mammals--I: rabies. Br Vet J 1984;140:96-106.

  10. Clark KA, Kelly VP, et al. Rabies vaccination: field observations during epizootics in dogs. Modern Vet Pract 1981;Dec:907-11.

  11. Blaucou J, Firon JP, Rollin PE. Defaut de reaction immunitaire du chien apres vaccination contre la rage. Etude d'un cas -- consequences. Rec Med Vet 1983;159(10):789-93.

Disclaimer   All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to

Page converted: 08/05/98


Safer, Healthier People

Morbidity and Mortality Weekly Report
Centers for Disease Control and Prevention
1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A


Department of Health
and Human Services

This page last reviewed 5/2/01