The confirmation of H5N1 avian influenza in backyard birds in Melipilla has raised health alerts in the country, in a context where the virus remains present both locally and globally. "The recent confirmation of H5N1 avian influenza in backyard birds in Melipilla highlights that this virus has not disappeared; rather, it has established itself as a persistent health risk," says María Jesús Hald, an epidemiologist at the Faculty of Medicine of Andrés Bello University. The specialist warns that this is not an isolated event but part of a broader trend.
In this regard, she explains that organizations such as the World Health Organization and the Food and Agriculture Organization of the United Nations have classified the spread of the virus as the largest geographical expansion recorded to date. In Chile, the virus's advance reached a critical point in 2022 when the Agricultural and Livestock Service reported its spread from the north to the far south. That year, the outbreak affected thousands of wild birds and caused high mortality in marine fauna.
"In 2022, significant mortality was recorded in marine fauna, including more than 20,000 sea lions according to official reports," details Hald. During 2023, the country faced its first confirmed human case and outbreaks in industrial farms, which necessitated the reinforcement of control measures. Globally, the expert emphasizes the magnitude of the phenomenon.
"Between 2003 and 2024, more than 870 human cases of H5N1 avian influenza have been confirmed worldwide, with a lethality rate close to 50%," she notes, although she clarifies that transmission between people remains extremely limited. Despite this scenario, Hald emphasizes that the current situation in Chile is under control. "The current scenario in Chile is, for now, contained: recent cases are concentrated in backyard and wild birds," she indicates, while highlighting that the country maintains its status free from highly pathogenic avian influenza in the commercial poultry industry.
However, she warns that "this should not be interpreted as an absence of risk, but as evidence that epidemiological surveillance is working," she asserts. Finally, the epidemiologist calls for vigilance. "Recent experience teaches us that early events are opportunities for containment.
The real risk is not in the detected case, but in the possibility of normalizing its occurrence," she concludes, emphasizing the need to maintain biosecurity, strengthen surveillance, and improve communication to avoid greater impacts.