In response to a number of questions submitted from the ProMED-mail Moderator to the USDA, Animal and Plant Health Inspection Service (APHIS), Veterinary Services (VS) with regard to the outbreak of rabbit hemorrhagic disease (RHD) that occurred in rabbits in the domestic area of an exotic animal facility in NY, I offer the following:

1. Currently available epidemiologic information about the outbreak of RHD that occurred in the affected facility is insufficient to ascribe an origin for the rabbit calicivirus isolated. We have information that rabbit meat from US-origin suppliers who receive rabbit meat from many sources including rabbit meat imported from China was prepared for the zoo carnivores in the same kitchen in which the rabbit diets were prepared. Food and other samples from the kitchen have been received and tested for rabbit caliciviruses at the USDA, APHIS, VS, Foreign Animal Disease Diagnostic Laboratory, Plum Island, NY. While RHD virus was isolated from the rabbits in the petting zoo, all samples from the kitchen have been negative for rabbit caliciviruses. USDA, APHIS does not regulate imported commercial rabbit meat.

An alternate scenario is infection from rabbit owners who visited the petting zoo. However, we have had no recent reports of RHD virus infections in rabbitries in the United States. In short, we have no unequivocal epidemiologic information on which to make a determination of the origin of the virus.

2. USDA, APHIS has not issued any alerts attributing the RHD outbreak at the facility to RHD-virus infected rabbit meat because we have insufficient information to make such a recommendation. It would be less than responsible to warn of "RHD virus-infected rabbit meat" when we have no idea if that is true. US experiences with RHD have involved backyard "herds" and now, the petting zoo.

3. USDA, APHIS has no indication that RHD virus-infected rabbit meat has been imported into the United States. However, the rabbit meat suppliers receive their supply from various companies, including one company that imports rabbit meat from China.

4. USDA, APHIS has no data to suggest that US-origin rabbit meat is fed at the affected facility. This is unclear because the company from which the zoo purchases is of US origin but receives meat from China through a chain of suppliers. There is no way to determine how much meat was directly from China and how much meat was of US origin.

5. The RHD viruses are considered exotic to the United States. As stated previously, "commercial" rabbit producers have not reported disease. Extensive tracebacks from this and earlier outbreaks have not yielded any indication of an associated origin from US rabbit raisers, including commercial producers. Therefore, no meat from infected rabbits reaches commercial distribution. It is improbable that US origin rabbit meat infected with RHD virus has been marketed to wholesale or retail outlets.--

Thomas E. Walton, DVM, PhD, ScD, Director
Centers for Epidemiology and Animal Health
USDA, Animal & Plant Health Inspection ServiceVeterinary Services
Fort Collins,
CO....................................tg/pg/es


RHD outbreak in New York - December 2001
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Sent: Tuesday, December 11, 2001 2:11 PM
Subject: Emergency Management Warning : Rabbit Hemorrhagic Disease (ViralHemorrhagic Disease of Rabbits ) in Flushing, New York

Rabbit Hemorrhagic Disease Confirmed in a Captive Exotic Animal Facility in Flushing, New York. Two out of six rabbits on exhibit in the domestic animal section at a captive exotic animal facility were found dead on Saturday, December 1 and Sunday, December 2, 2001, respectively. Two additional rabbits were in an off exhibit area for a total of eight rabbits in the collection. This is not considered a zoonotic disease. Animals were necropsied by zoo pathologists and lesions consistent with rabbit hemorrhagic disease (RHD) were found. Samples from the dead rabbits were sent to the Foreign Animal Disease Diagnostic Laboratory (FADDL) on Plum Island, NY. Test results were positive by hemagglutination on one rabbit and negative on the other on Friday, December 7, 2001. A third exhibited rabbit died on Sunday, December 9, 2001.

The remaining rabbits were quarantined and isolated from other animals. The five remaining rabbits were euthanized on Monday, December 10, 2001, and additional samples will be sent to FADDL. Cleaning and disinfectionof the area will be done. From the epidemiological data gathered so far, the source of the virus is unknown.

APHIS, Veterinary Services (VS), the State Department of Agriculture of New York, and facility managers are working together to address thissituation. VS will assist the affected State in the depopulation and cleaning and disinfecting of the premises. VS will also investigate reports of suspect RHD as part of its foreign animal disease surveillance program and will continue to diagnose suspect cases at FADDL.

DNA Sequencing Results from the Utah/Illinois RHD Outbreak in August 2001> The sequence alignments were taken from the polymerase region of the RHDV genome. It showed distinct differences between the 3 isolates (Mexico, Korea, Utah) and the Iowa isolate. The sequence pair distance of the 3 isolates had percent similarities of over 95% while the Iowa isolate differed more from the others. The biggest difference was between theIowa and the Utah isolates at 14.5%.. If you have any questions, please contact the USDA, APHIS, Veterinary Services, Emergency Programs staff at 301-734-8073, 800-940-6524, or EMOC@APHIS.USDA.GOV.

Please forward this information to other Federal, State, and industry counterparts as necessary. -----definitions--------- Emergency Management Issue is for information with no impact on APHIS Emergency Management Notice is an ongoing incident with potential impacton APHIS Emergency Management Warning is an ongoing incident with almost certain impact on APHIS


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RABBIT HEMORRHAGIC DISEASE OUTBREAK- USA (UTAH) August 2001
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A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

From: ProMED-mail
Source: Bruce Akey [edited]
Viral hemorrhagic disease in Utah
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A telephone call from the Utah state diagnostic laboratory today informed me of a confirmed case of viral hemorrhagic disease in a rabbitry in the state. The diagnosis has been confirmed by testing at Plum Island. Preliminary epidemiological work does not indicate a likely source. This seems to be mirroring the previous outbreak in Iowa, for which no source was ever determined. Tracing the movement of rabbits from the affected farm is continuing.
-- Bruce L Akey, MS, DVMChief, Office of Laboratory Services
Virginia Dept. Agriculture and Consumer Svcs.1100 Bank St, Suite 615
Richmond, VA 23219(804) 786-9202*****

[2]Date: Wed, 22 Aug 2001 03:12:34 +0800
From: "bunny"
Source: United States Department of Agriculture Animal and Plant Health
Inspection Service [edited]
Emergency management warning: rabbit calicivirus disease
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Rabbit calicivirus disease (also known as viral hemorrhagic disease of rabbits) has been identified in a rabbitry of about 750 rabbits in Utah County, Utah. The owners have lost about 65 rabbits. The premises is quarantined, and animal movements into and out of the premises [are being traced].Trace outs were found in Montana and Illinois. The Utah origin rabbits remained on the Montana premises. Two other rabbits from the Montana premises were destined for slaughter via a tractortrailer containing about 3600 rabbits. Movement restrictions were placed on the truck in Idaho. The premises in Illinois is also under quarantine and no further movement of rabbits has been identified from that premises; that owner has lost about 20 rabbits.

There is still no information on the source of the virus introduction. All trace outs from the initial Utah premises are complete. Rabbits were sent to only three other premises -- in Utah, Montana, and Illinois. Montana traced the movement of rabbits from the premises that received the Utah rabbits. Two other rabbits from that Montana premises, on route to the truck for slaughter, were [in contact] with rabbits destined for the Montana state fair. The rabbits at the state fair were quarantined by the state veterinarian.

The Animal and Plant Health Inspection Service (APHIS), veterinary services, and the state departments of agriculture of Utah, Montana, Idaho, and Illinois are working together to address the situation. Veterinary services will assist the affected states in the depopulation and cleaning and disinfecting of the premises. They also will investigate reports of suspected rabbit calicivirus disease as part of the foreign animal disease surveillance program and will continue to diagnose suspected cases at the United States Department of Agriculture (USDA) Foreign Animal Disease Diagnostic Laboratory (FADDL).

A fact sheet and questions and answers are posted on the APHIS website: . The Utah State laboratory submitted samples to Plum Island on August 15. Rabbit calicivirus disease or toxic hepatopathy was suspected on the basis of the clinical history and microscopic lesions in the liver. On 17 Aug, hemagglutination tests and electron microscopy carried out by FADDL confirmed the diagnosis. The state and federal offices were notified and foreign animal disease investigations began immediately. Epidemiological information is being collected and additional samples are being sent to FADDL.

Rabbit calicivirus was first reported in 1984 in the People's Republic of China. The first report of the virus in the western hemisphere was in Mexico City in 1988. Mexico was successful in eradicating the virus. Rabbit calicivirus disease is a highly infectious viral disease of the European rabbit (_Oryctolagus cuniculus_). This is the species from which all domestic and commercial rabbits in the United States are derived. Rabbits native to North America (cottontail rabbits and jack rabbits) do not develop clinical disease and are not susceptible to rabbit calicivirus.

Humans and other mammals are not affected by the rabbit calicivirus. Rabbit calicivirus is a highly contagious virus that can be transmitted by direct contact with infected rabbits or indirectly by contact with objects contaminated with virus. The virus damages the liver, intestines, and lymphatic tissue and causes terminal blood clots. Infected rabbits die within 6 to 24 hours of the onset of a fever, with few clinical signs.-- ProMED-mail

[Checking records of the Office International des Epizooties records: "19 June 2000, Dr Alfonso Torres, deputy administrator, Veterinary Services, United States Department of Agriculture, Washington, DC: End of previous report period: 10 April 2000 (see Disease Information, 13 [14], 55, dated 14 April 2000). End of this report period: 13 June 2000. The investigation of rabbit haemorrhagic disease in Crawford County, Iowa, was considered closed as of 12 May 2000. An extensive epidemiological investigation failed to determine how the rabbits became infected. No new cases of rabbit calicivirus disease have been reported." Otherwise it has only been reported from Cuba in the Americas. Mod.MHJ]...............tg/mhj/sh
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Rabbit Hemorrhagic Disease Outbreak in the USA-March 2001


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