OIE: Highly pathogenic avian influenza(H7N3), United States of America

Information received on 09/04/2020 from Dr Mark Davidson, Associate Administrator, USDA-APHIS, United States Department of Agriculture, Washington, United States of America
Summary
Report type Immediate notification
Date of start of the event 06/04/2020
Date of confirmation of the event 08/04/2020
Report date 09/04/2020
Date submitted to OIE 09/04/2020
Reason for notification Recurrence of a listed disease
Date of previous occurrence 11/08/2017
Manifestation of disease Clinical disease
Causal agent High pathogenic avian influenza
Serotype H7N3
Nature of diagnosis Laboratory (advanced)
This event pertains to a defined zone within the country
New outbreaks (1)
Outbreak 1 Chesterfield County, Chesterfield, South Carolina
Date of start of the outbreak 06/04/2020
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Farm
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 34160 1583 32577 0
Affected population Commercial meat-type turkey flock
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 34160 ** 1583 32577 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds ** 4.63% ** 100.00%
*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 Highly pathogenic avian influenza (HPAI) H7N3 was confirmed on one commercial meat-type turkey premises in Chesterfield County, South Carolina. Clinical signs included respiratory signs, snicking, and increased mortality. State officials have quarantined the affected premises and depopulation of birds has been completed. Movement controls have also been implemented. This is the first confirmed case of HPAI in commercial poultry in the United States this year. The premises has an epidemiological link to another South Carolina premises affected recently by Low pathogenic avian influenza (LPAI) H7N3. The USDA Animal Plant Health Inspection Service (APHIS) and South Carolina State Veterinarian抯 Office, part of Clemson University Livestock Poultry Health (CULPH), continue conducting a comprehensive epidemiological investigation and enhanced surveillance already underway in the area.
Control measures
Measures applied
  • Movement control inside the country
  • Surveillance outside containment and/or protection zone
  • Surveillance within containment and/or protection zone
  • Quarantine
  • Official disposal of carcasses, by-products and waste
  • Stamping out
  • Zoning
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • Disinfection
Diagnostic test results
Laboratory name and type Species Test Test date Result
National Veterinary Services Laboratories (National laboratory) Birds gene sequencing 08/04/2020 Positive
National Veterinary Services Laboratories (National laboratory) Birds real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 08/04/2020 Positive
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.