New Zealand, - Outbreaks of Infectious bursal disease (Gumboro disease) in birds in farms in Otago

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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 03/06/2019 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

New outbreaks (1)

Outbreak 1 Waikouaiti, Waikouaiti, Dunedin City, Otago Date of start of the outbreak 03/06/2019 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.

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https://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=31586

[Pathfinder]

Infectious bursal disease (Gumboro disease), New Zealand

Information received on 11/09/2019 from Dr Tony Zohrab, , Policy and Trade Branch, Ministry for Primary Industries, Wellington , New Zealand

Summary Report type Follow-up report No. 1 Date of start of the event 10/06/2019 Date of confirmation of the event 03/09/2019 Report date 11/09/2019 Date submitted to OIE 11/09/2019 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)

New outbreaks (1)

Outbreak 1 Hillgrove, Waitaki District, Otago Date of start of the outbreak 19/08/2019 Outbreak status Continuing (or date resolved not provided) Epidemiological unit Farm Affected animals Species Susceptible Cases Deaths Killed and disposed of Slaughtered Birds 160000 10 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 160000 10 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 The Ministry for Primary Industries (MPI) is investigating the possible finding of infectious bursal disease type 1 virus in a layer chicken farm enterprise. Routine surveillance by the poultry industry detected seroconversion for IBD virus on a chicken farm near Dunedin in the South Island of New Zealand. Preliminary testing as part of an MPI investigation suggests the presence IBD type 1 virus. Samples have been sent to the OIE reference laboratory in France for confirmatory testing. Tracing and testing of in-contact properties is in place. A flock on a second farm which is directly linked to the Waikouaiti farm and is part of the same enterprise has tested positive for IBD virus on serology. A delimiting survey of South Island egg and meat production facilities is underway, and movement controls have been applied to both affected premises. No clinical disease or change in production parameters is evident in either of the affected farms. 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). The initial notification and this follow-up report 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. 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 Movement control inside the country Traceability Disinfection Vaccination prohibited No treatment of affected animals Measures to be applied No other measures

Diagnostic test results Laboratory name and type Species Test Test date Result Laboratory for investigation and swine, poultry and fish study, Ploufragan, France (OIE Reference Laboratory) Birds gene sequencing Pending

Future Reporting The event is continuing. Weekly follow-up reports will be submitted.

...

https://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=31673