Mexico will start vaccinating birds in high-risk areas this week to prevent the spread of the highly contagious H5N1 strain of bird flu in the country, Reuters reported, citing authorities on Tuesday.

Last month, Mexican authorities detected a severe H5N1 strain of avian influenza at a commercial farm in Nuevo Leon state on the border with the United States.

Commonly called bird flu, the disease is often carried by wild birds in autumn and winter, but experts are concerned that the H5N1 strain has not followed previous trends by subsiding during the northern hemisphere summer.

The variant's rapid spread has prompted massive culls this year. At least 52 million birds have been slaughtered for health reasons so far in the Europe, Mexico's agriculture ministry said, compared with 50.2 million in the United States.