Eight days ago, Media Reports: H5N2 Poultry Outbreak – Sinaloa, Mexico, we looked at multiple media reports of an outbreak of H5N2 on a farm in Sinaloa. Mexico’s Agricultural Ministry (SAGARPA) and National Health Service, Food Safety and Food Quality (SENASICA ) websites have been strangely quiet on the issue, however.
While in recent years it has been mostly been HPAI H7N3 viruses that have cropped up in Mexico (see OIE: Mexico Reports HPAI H7N3 In Two States), Mexico has a long history of LPAI (low pathogenic) H5N2 outbreaks going back more than 20 years (1994).
LPAI avian viruses are considered less dangerous than HPAI viruses, but those of the H5 and H7 subtype have been known to convert to a higher pathogenicity, hence the need to control both types of viruses. It is not immediately clear why, more than three weeks after the event began, today’s report indicates that culling has not been completed.
Source of the outbreak(s) or origin of infection
- Unknown or inconclusive
Following the epidemiological surveillance activities carried out by the Veterinary Services of Mexico, avian influenza subtype H5N2 has been identified ; the intravenous pathogenicity test revealed that it corresponds to a low pathogenic avian influenza virus. The virus was isolated in a commercial farm of laying hens in the State of Sinaloa. The corresponding epidemiological investigation was initiated, including sampling in 4 industrial poultry farms and in 33 backyard poultry farms located in the 10-km zone around the outbreak, with a total of 720 samples of blood serum and tracheal and cloacal swabs, without detecting evidence of virus circulation. The production unit has been quarantined and a sanitary barrier has been set up. A humanely slaughter of birds programme will be launched even though it is a virus of low pathogenicity. Note by the OIE Animal Health Information Department: H5 and H7 avian influenza in its low pathogenic form in poultry is a notifiable disease as per Chapter 10.4. on avian influenza of the Terrestrial Animal Health Code (2015).
- Movement control inside the country
- Vaccination prohibited
- No treatment of affected animals
Measures to be applied
- Disinfection / Disinfestation
- Stamping out