Rabbit haemorrhagic disease,
United States of America
Information received on 02/07/2020 from Dr Mark Davidson, Associate Administrator, USDA-APHIS, United States Department of Agriculture, Washington, United States of America
Summary
Report type Follow-up report No. 22 (Final report)
Date of start of the event 08/07/2019
Date of confirmation of the event 17/07/2019
Report date 02/07/2020
Date submitted to OIE 02/07/2020
Date event resolved 03/07/2020
Reason for notification Recurrence of a listed disease
Date of previous occurrence 16/04/2019
Manifestation of disease Clinical disease
Causal agent Rabbit haemorrhagic disease virus
Serotype RHDV2
Nature of diagnosis Laboratory (advanced)
This event pertains to a defined zone within the country
Related reports Immediate notification (19/07/2019)
Follow-up report No. 1 (08/08/2019)
Follow-up report No. 2 (16/08/2019)
Follow-up report No. 3 (30/08/2019)
Follow-up report No. 4 (03/12/2019)
Follow-up report No. 5 (07/01/2020)
Follow-up report No. 6 (06/03/2020)
Follow-up report No. 7 (13/03/2020)
Follow-up report No. 8 (27/03/2020)
Follow-up report No. 9 (06/04/2020)
Follow-up report No. 10 (13/04/2020)
Follow-up report No. 11 (20/04/2020)
Follow-up report No. 12 (27/04/2020)
Follow-up report No. 13 (05/05/2020)
Follow-up report No. 14 (13/05/2020)
Follow-up report No. 15 (19/05/2020)
Follow-up report No. 16 (27/05/2020)
Follow-up report No. 17 (01/06/2020)
Follow-up report No. 18 (09/06/2020)
Follow-up report No. 19 (17/06/2020)
Follow-up report No. 20 (23/06/2020)
Follow-up report No. 21 (29/06/2020)
Follow-up report No. 22 (02/07/2020)
New outbreaks (10)
Outbreak 1 Bernalillo County, Bernalillo, New Mexico
Date of start of the outbreak 03/05/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Cottontail rabbits:Sylvilagus(Leporidae) 3 3 0 0
Affected population Wild Cottontail rabbits (Sylvilagus sp)
Outbreak 2 Arapahoe County, Arapahoe, Colorado
Date of start of the outbreak 19/05/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Backyard
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Rabbits 20 11 0
Affected population Non-commercial domestic rabbits (Oryctolagus cuniculus)
Outbreak 3 Montezuma County, Montezuma, Colorado
Date of start of the outbreak 27/05/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Backyard
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Rabbits 33 15 0
Affected population Non-commercial domestic rabbits (Oryctolagus cuniculus)
Outbreak 4 Santa Fe County, Santa Fe, New Mexico
Date of start of the outbreak 05/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Backyard
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Rabbits 1 1 0
Affected population Non-commercial domestic rabbit (Oryctolagus cuniculus)
Outbreak 5 Orange County, Orange, California
Date of start of the outbreak 16/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Cottontail rabbits:Sylvilagus(Leporidae) 1 1 0 0
Affected population Wild Desert cottontail rabbit (Sylvilagus audubonii)
Outbreak 6 Clark County, Clark, Nevada
Date of start of the outbreak 16/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Desert Cottontail:Sylvilagus audubonii(Leporidae) 1 1 0 0
Affected population Wild Desert cottontail rabbit (Sylvilagus audubonii)
Outbreak 7 Potter County, Potter, Texas
Date of start of the outbreak 17/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Cottontail rabbits:Sylvilagus(Leporidae) 4 4 0 0
Affected population Wild Cottontail rabbits (Sylvilagus sp)
Outbreak 8 Bernalillo County, Bernalillo, New Mexico
Date of start of the outbreak 20/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Backyard
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Rabbits 1 1 1 0 0
Affected population Non-commercial domestic rabbit (Oryctolagus cuniculus)
Outbreak 9 Kimble County, Kimble, Texas
Date of start of the outbreak 22/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Backyard
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Rabbits 2 1 0
Affected population Non-commercial domestic rabbits (Oryctolagus cuniculus)
Outbreak 10 Sanpete County, Sanpete, Utah
Date of start of the outbreak 30/06/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Not applicable
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
European Rabbit:Oryctolagus cuniculus(Leporidae) 7 4 0 0
Affected population Feral European rabbits (Oryctolagus cuniculus)
Summary of outbreaks Total outbreaks: 10
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Cottontail rabbits:Sylvilagus(Leporidae) 8 8 0 0
Rabbits 57 1 ** 29 0 0
Desert Cottontail:Sylvilagus audubonii(Leporidae) 1 1 0 0
European Rabbit:Oryctolagus cuniculus(Leporidae) 7 ** 4 0 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Cottontail rabbits:Sylvilagus(Leporidae) ** ** 100.00% **
Rabbits ** 50.88% ** **
Desert Cottontail:Sylvilagus audubonii(Leporidae) ** ** 100.00% **
European Rabbit:Oryctolagus cuniculus(Leporidae) ** 57.14% ** 57.14%
*Removed from the susceptible population through death, destruction and/or slaughter
**Not calculated because of missing information
Epidemiology
Source of the outbreak(s) or origin of infection
  • Unknown or inconclusive
Epidemiological comments Update 2 July 2020: Utah (UT)--There has been one feral European rabbit (Oryctolagus cuniculus) detection of RHDV2 in Sanpete County. Utah State Animal Health Officials and the United States Department of Agriculture (USDA), Animal and Plant Health Inspection Services (APHIS) have begun an epidemiological investigation into the outbreaks. California (CA)--There has been one wild Cottontail rabbit (Sylvilagus sp) detection of RHDV2 in Orange County. California State Animal Health Officials and the USDA, APHIS continue an epidemiological investigation into the current outbreaks. Nevada (NV)--There has been one wild Desert cottontail rabbit (Sylvilagus audubonii) detection of RHDV2 in Clark County. Nevada State Animal Health Officials and the USDA, APHIS continue an epidemiological investigation into the current outbreaks. Colorado (CO)--RHDV2 confirmed in domestic rabbits (Oryctolagus cuniculus) from two additional non-commercial premises. Total positive premises in Colorado is six. The affected premises have been quarantined and depopulation is pending. Colorado State Animal Health Officials and USDA, APHIS continue an epidemiological investigation into the current outbreaks. Arizona (AZ)--Arizona State Animal Health Officials and the USDA, APHIS continue an epidemiological investigation into the current outbreaks. Texas (TX)--RHDV2 confirmed in domestic rabbits (Oryctolagus cuniculus) on one additional non-commercial premises in Kimble County. Total positive premises in Texas is eight. There has also been one wild Cottontail rabbit (Sylvilagus sp) detection of RHDV2 in Potter County. Texas State Animal Health Officials and the USDA, APHIS continue an epidemiological investigation into the current outbreaks. New Mexico (NM)--RHDV2 confirmed in domestic rabbits (Oryctolagus cuniculus) from two additional non-commercial premises. Total positive premises in New Mexico is 41. Forty of the affected premises have been quarantined and depopulation has been completed on 30 of the affected premises. Disposal activities are ongoing. Eight of the affected premises have completed cleaning and disinfection activities and continue a 90-day fallow period. New Mexico State Animal Health Officials and the USDA, APHIS continue their epidemiological investigation into the current outbreaks. General clinical signs seen in confirmed cases from all the affected states include lethargy, seizures, and sudden death. All affected States have received or are pursuing import of European Union-licensed RHDV2 vaccine for emergency use by special approval of the USDA. Administration of RHDV2 vaccine has begun in New Mexico, Colorado, California and Texas. In all States, State Animal Health Officials direct the use of the vaccine including record and ID requirements. State Animal Health Officials in states where feral or wild lagomorph detections of RHDV2 have occurred were given permission by the USDA to begin designating laboratories that can perform RHDV2 testing for their state following standard operating procedures and a testing algorithm provided by the National Veterinary Services Laboratories. Laboratories have been designated in Colorado, California and New Mexico.
Control measures
Measures applied
  • Vaccination in response to the outbreak (s)
  • Surveillance within containment and/or protection zone
  • Traceability
  • Quarantine
  • Disinfection
  • No treatment of affected animals
Measures to be applied
  • No other measures
Diagnostic test results
Laboratory name and type Species Test Test date Result
National Veterinary Services Laboratories (National laboratory) Cottontail rabbits reverse transcription - polymerase chain reaction (RT-PCR) 22/06/2020 Positive
National Veterinary Services Laboratories (National laboratory) Desert Cottontail reverse transcription - polymerase chain reaction (RT-PCR) 22/06/2020 Positive
National Veterinary Services Laboratories (National laboratory) European Rabbit antigen (Ag) detection ELISA 30/06/2020 Positive
National Veterinary Services Laboratories (National laboratory) European Rabbit reverse transcription - polymerase chain reaction (RT-PCR) 30/06/2020 Positive
National Veterinary Services Laboratories (National laboratory) Rabbits reverse transcription - polymerase chain reaction (RT-PCR) 25/06/2020 Positive
National Veterinary Services Laboratories (National laboratory) Rabbits reverse transcription - polymerase chain reaction (RT-PCR) 30/06/2020 Positive
National Wildlife Health Center (National laboratory) Cottontail rabbits reverse transcription - polymerase chain reaction (RT-PCR) 30/06/2020 Positive
Future Reporting
The event cannot be considered resolved, but the situation is sufficiently stable. No more follow-up reports will be sent. Information about this disease will be included in the next six-monthly reports.
Map of outbreak locations