Review of the Highly Pathogenic Avian Influenza in Argentina in 2023: Chronicle of Its Emergence and Control in Poultry

Abstract

Highly pathogenic avian influenza (HPAI) is a highly contagious viral disease that represents a significant threat to poultry production worldwide. Variants of the HPAI virus (HPAIV)H5A/Goose/GuangDong/1/96 (H5 Gs/GD/96) lineage have caused five intercontinental epizooticwaves, with the most recent, clade 2.3.4.4b, reaching Argentina in February 2023. Initially detectedin wild birds, the virus quickly spread to backyard and commercial poultry farms, leading to economic losses, including the loss of influenza-free status (IFS). By March/April 2023 the epidemichad peaked and vaccination was seriously considered. However, the success of strict stamping-outmeasures dissuaded the National Animal Health Authority (SENASA) from authorizing any vaccine. Suspected cases sharply declined by May, and the last detection in commercial poultry wasreported in June. The effective control and potential eradication of HPAIV in Argentina were due toSENASA’s early detection and rapid response, supported by private companies, veterinarians, andother stakeholders. Stamping-out measures have been effective for virus elimination and reducedfarm-to-farm transmission; however, as the virus of this clade may remain present in wild birds,the risk of reintroduction into poultry production is high. Therefore, maintaining continuous activesurveillance will be crucial for promptly detecting any new HPAIV incursion and taking appropriateaction to contain virus dissemination.