OIE: Highly pathogenic avian influenza(H7N3), Mexico

Information received on 09/03/2018 from MVZ Joaquín Braulio Delgadillo álvarez, Director General de Salud Animal, Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA) Secretaría de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación, Ministerio de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación, México, Mexico

Summary

Report type Immediate notification
Date of start of the event 12/02/2018
Date of confirmation of the event 03/03/2018
Report date 09/03/2018
Date submitted to OIE 10/03/2018
Reason for notification Recurrence of a listed disease
Date of previous occurrence 31/05/2017
Manifestation of disease Clinical disease
Causal agent Highly pathogenic avian influenza virus
Serotype H7N3
Nature of diagnosis Clinical, Laboratory (advanced)
This event pertains to a defined zone within the country

New outbreaks

Summary of outbreaks Total outbreaks: 2
Outbreak Location
  • GUANAJUATO ( San Felipe, San Felipe )
  • QUERETARO ( Cadereyta de Montes, Cadereyta de Montes )
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Birds 1926 1387 1387 539 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds 72.01% 72.01% 100.00% 100.00%

* Removed from the susceptible population through death, destruction and/or slaughter;

Epidemiology

Source of the outbreak(s) or origin of infection
  • Introduction of new live animals
Epidemiological comments A farm was detected in Guanajuato within the framework of the permanent National program for active epidemiological surveillance. It initially had 1,400 Rhodes Island Red chickens, before the introduction of 500 white chickens towards the end of the laying phase, supposedly coming from a farm in Jalisco where vaccination is applied. This was verified through serology on 30 sera with two titers of 1:256, four titers of 1:512 and 24 titers of 1:1024. This introduction is considered to be the source of infection of the susceptible birds. Isolation in Querétaro was obtained after the reporting by an authorized laboratory, which provided the official laboratory with the samples.
As difficulties were faced during typing of the virus, several diagnostic assays were performed until confirmation. Isolated viruses in Guanajuato and Querétaro presented an IVIP of 2.84 and 2.86, respectively.
In both cases, measures to control the epidemic were applied, including quarantine of the premises and killing of the birds. Pre-emptively, a focal zone and a perifocal zone of three and ten kilometers respectively were implemented, where the absence of the disease has been verified. The National veterinary services will keep the epidemiological surveillance going and inform the OIE about any evolution.

Control measures

Measures applied
  • Movement control inside the country
  • Screening
  • Quarantine
  • Official disposal of carcasses, by-products and waste
  • Stamping out
  • Zoning
  • Disinfection
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • No other measures

Diagnostic test results

Laboratory name and type SENASICA level-3 biosecurity laboratory ( National laboratory )
Tests and results
Species Test Test date Result
Birds haemagglutination inhibition test (HIT) 18/02/2018 Positive
Birds intravenous pathogenicity index (IVPI) test 19/02/2018 Positive
Birds neuraminidase inhibition assay 03/03/2018 Positive
Birds virus isolation 19/02/2018 Positive
Birds virus sequencing 23/02/2018 Positive

Future Reporting

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