Infectious bursal disease (Gumboro disease),
New Zealand
Information received on 03/09/2019 from Dr Tony Zohrab, , Policy and Trade Branch, Ministry for Primary Industries, Wellington , New Zealand
Summary
Report type Immediate notification
Date of start of the event 10/06/2019
Date of confirmation of the event 03/09/2019
Report date 03/09/2019
Date submitted to OIE 03/09/2019
Reason for notification Recurrence of a listed disease
Date of previous occurrence 1999
Manifestation of disease Sub-clinical infection
Causal agent Infectious bursal disease virus
Serotype 1
Nature of diagnosis Laboratory (advanced)
This event pertains to the whole country
Related reports Immediate notification (03/09/2019)
Follow-up report No. 1 (11/09/2019)
Follow-up report No. 2 (19/09/2019)
Follow-up report No. 3 (27/09/2019)
Follow-up report No. 4 (10/10/2019)
Follow-up report No. 5 (22/10/2019)
Follow-up report No. 6 (05/11/2019)
Follow-up report No. 7 (21/11/2019)
New outbreaks (1)
Outbreak 1 Waikouaiti, Waikouaiti, Dunedin City, Otago
Date of start of the outbreak 10/06/2019
Outbreak status Continuing (or date resolved not provided)
Epidemiological unit Farm
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 489500 46 0 0 0
Affected population A commercial layer and rearing chicken farm.
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 489500 46 0 0 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds 0.01% 0.00% 0.00% 0.00%
*Removed from the susceptible population through death, destruction and/or slaughter
Epidemiology
Source of the outbreak(s) or origin of infection
  • Unknown or inconclusive
Epidemiological comments As part of routine surveillance for infectious bursal disease (IBD) virus by the poultry industry, ten layer hens tested sero-positive in a chicken flock near Dunedin in the South Island of New Zealand. Further testing as part of a Ministry for Primary Industries investigation has found evidence of infection in two additional layer flocks and three rearer flocks on the same farm. No clinical disease or change in production parameters is evident in any of the positive flocks. MPI is undertaking a pathway assessment, but as the findings are isolated to premises with a high health status and there are no clinical signs, MPI is considering whether this finding may be vaccine-associated. New Zealand previously had an incursion of a vaccine associated infectious bursal disease virus serotype 1 in 1993. The incursion was attributed to the use of a contaminated vaccine in a single hatchery. An industry led eradication programme was undertaken with the last serum reactor farm removed in 1999. Since that time, the New Zealand poultry industry have run a sero-surveillance programme with annual testing of commercial layer, rearing, meat-chicken and meat-chicken breeder farms. A non-pathogenic infectious bursal disease virus serotype 2 (IBDV2) has been previously recognised as present in New Zealand (Rawdon et al, 2019). This notification is being provided on the basis of preliminary test results suggesting the presence of a strain of infectious bursal disease virus serotype 1. Further testing is being completed at the OIE reference laboratory in France to confirm these initial results. A follow-up report will be provided to confirm or annul this report. Reference: Rawdon et al. Detection of infectious bursal disease virus serotype 2 (IBDV-2) in New Zealand poultry and waterfowl. Surveillance, Volume 46, Issue 1, pp 4-7, Mar 2019.
Control measures
Measures applied
  • Traceability
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • Movement control inside the country
  • Disinfection
Diagnostic test results
Laboratory name and type Species Test Test date Result
National Animal Health Laboratory (National laboratory) Birds gene sequencing 12/08/2019 Positive
National Animal Health Laboratory (National laboratory) Birds gene sequencing 20/08/2019 Positive
National Animal Health Laboratory (National laboratory) Birds real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) 06/08/2019 Positive
National Animal Health Laboratory (National laboratory) Birds reverse transcription - polymerase chain reaction (RT-PCR) 08/08/2019 Positive
National Animal Health Laboratory (National laboratory) Birds reverse transcription - polymerase chain reaction (RT-PCR) 14/08/2019 Positive
National Animal Health Laboratory (National laboratory) Birds virus neutralisation test (VNT) 19/07/2019 Positive
Laboratory for investigation and swine, poultry and fish study, Ploufragan, France (OIE Reference Laboratory) Birds gene sequencing Pending
Poultry Veterinary Services (Private Laboratory) Birds antibody detection ELISA 28/06/2019 Positive
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.
Map of outbreak locations