Mexican authorities decreed a health emergency due to an outbreak of avian flu in the central state of Guanajuato, where some 582,000 domestic fowl exposed to the virus could be slaughtered to eradicate it, officials said.

The Sagarpa agriculture secretariat said in a communique Friday that technicians of the National Food Health, Safety and Quality Service, or Senasica, confirmed "the presence of the H7 avian flu virus on seven farms of the Bachoco company in Guanajuato.

Sagarpa said that since Wednesday night an emergency prevention operation has been in force due to the increased mortality from "suspected avian flu," so that tecnicians were sent to inspect the Bachoco farms in the Guanajuato municipalities of Dolores Hidalgo and San Luis de la Paz.

Official laboratories said that clinical diagnoses "will determine the number of poultry that must be slaughtered to eradicate the outbreak."

Mexican authorities said the outbreak "will not affect the national supply of poultry products," since Mexico has 137 million laying hens, of which 2.8 million are in Guanajuato, or 2.35 percent of the total.

They also said that this virus is exclusive to birds and represents no risks to humans.

Last June saw an outbreak of the same virus that led authorities and producers to slaughter more than 22 million affected poultry. EFE