The World Organisation for Animal Health (WOAH) reported that the situation concerning highly pathogenic avian influenza (HPAI) in both Brazil and Mexico has been resolved.
WOAH issued separate reports on each country on December 6.
Brazil
While HPAI has never been in any commercial poultry flocks in Brazil, the presence of an H5N1 variant of the virus was first confirmed in migratory wild birds in May 2023. Since that time, 871 investigations of probable cases of avian respiratory and nervous syndrome have been carried out, and 161 outbreaks of HPAI have been detected in wild birds (158) and backyard birds (3), WOAH reported. A total of 1,357 birds were affected in these outbreaks.
Those cases appeared in eight states: Sao Paulo, Espirito Santo, Rio de Janeiro, Santa Catarina, Parana, Rio Grande do Sul, Bahia and Mato Grosso do Sul.
Since the onset of the outbreaks, there has not been a consistent increase in the number of outbreaks, and there have been two detection peaks: June 2023 (37 outbreaks) and September-October 2023 (28 and 27 outbreaks, respectively). After that, the number of outbreaks stabilized with sporadic detections, until reaching complete remission. All outbreaks have been resolved and closed.
Active surveillance for HPAI remains in place in Brazil.
Mexico
In July, the presence of H5N1 HPAI was confirmed at a single farm in Temascalcingo that was the home to 80 native birds. The premises had no link to commercial poultry farms and the nearest poultry production unit was 12 kilometers away.
Control measures at the farm were conducted and no new instances of HPAI were reported. With all criteria met to get an avian influenza-free designation, the situation is considered resolved, WOAH stated.
WOAH still has an active report concerning H7N3 HPAI in poultry, but no new cases have been reported since May.
View our continuing coverage of the global avian influenza situation.
