Summary
Report type: immediate notification
Started: 9 Nov 2021
Confirmed: 10 Nov 2021
Reported: 10 Nov 2021
Reason for notification: recurrence
Last occurrence: 19 Jun 2021
Causal agent: highly pathogenic avian influenza virus
Serotype: H5N8
Nature of diagnosis: clinical, laboratory
This event pertains to a defined zone within the country.

Outbreak location: Yokote City, Yokote, Akita
Started: 9 Nov 2021
Epidemiological unit: farm
Animals affected:
Species / Susceptible / Cases / Deaths / Killed and disposed of /
Slaughtered or killed for commercial use / Vaccinated
Birds / 143 000 / 2 / 89 / 142 911 / 0 / 0

Epidemiology
Source of the outbreak(s) or origin of infection: unknown or
inconclusive
Epidemiological comments: On 9 Nov 2021, the local veterinary service
in Akita Prefecture received a notification from a domestic laying hen
farm on an increase in the number of dead birds. The samples were
collected from dead birds by the local veterinary service (Livestock
Hygiene Service Centre; LHSC) and tested positive for influenza A
virus by antigen-capture kits. On 10 Nov [2021], the LHSC conducted
RT-PCR and RRT-PCR tests and confirmed that the subtype was H5. On 11
Nov, the National Institute of Animal Health (NIAH) conducted
the sequencing test and confirmed that the subtype of the virus was
H5N8, and causative virus was determined as high pathogenicity avian
influenza. Stamping-out policy is applied to the affected farm.
Destruction of all the susceptible birds in the affected farm is being
implemented. Movement and shipment restrictions are imposed on the
farms within a radius of 3 km and 3-10 km of the
affected farm, respectively.

Control measures at event level
Domestic control measures applied: official disposal of carcasses,
by-products, and waste; traceability; quarantine; screening; stamping
out; disinfection; movement control inside the country; ante- and
post-mortem inspections

Wild control measures applied: screening

Diagnostic test results
Laboratory name and type / Species / Outbreaks / Test / Test date /
Result
National Institute of Animal Health (national laboratory) / birds / 1
/ gene sequencing / 11 Nov 2021 / positive
Livestock Hygiene Service Centre (local laboratory) / birds / 1 /
real-time reverse transcription polymerase chain reaction (rRT-PCR) /
10 Nov 2021 / positive
Livestock Hygiene Service Centre (local laboratory) / birds / 1 /
reverse transcription-polymerase chain reaction (RT-PCR) / 10 Nov 2021
/ positive