Dr. Luke blamed himself for not having thought to examine the boy a day earlier. If she had treated the boy for influenza, she could have saved him.
But the warning she raised and the resulting emergency actions demonstrate the strength of Cambodia's disease tracking system and its importance to the global biosurveillance system.
It is the result of many years of international and local investment, training and public education. This shows that frontline work in low-income countries is becoming increasingly important to global systems for detecting zoonotic diseases – pathogens that jump between animals and humans, like COVID-19. The goal is to identify and contain them, buy time to produce enough vaccines or drugs to treat them, or embark on a frantic mission to develop new ones.
a growing threat
H5N1 is one of many viruses that cause influenza in birds. Since its emergence in Hong Kong in 1996, it has evolved into a version that causes outbreaks in wild and farmed birds and occasionally spreads to humans.
In 2020, a particularly virulent new virus caught the attention of scientists as it spread along migratory routes into parts of Africa, Asia and Europe.
By 2022, the virus had reached North and South America and was killing wild and domestic animals, including livestock and marine mammals.
So scientists were alarmed when they reported two people infected with H5N1 in Cambodia in February 2023. Was this a new version of the virus returning to Asia and killing people? Scientists have discovered that the virus has been present in birds throughout that time, but there have been no such human cases in the country for nearly a decade.
Genetic analysis revealed that the virus infecting Cambodians was a familiar subtype and not one from the Americas. Nonetheless, last year Cambodia reported 11 people infected with bird flu, five of whom died. This is more than anywhere else in the world.
Global anxiety over H5N1 has heightened in recent weeks. The virus was discovered in goats and dairy cows in the United States, and then in Texas farm workers who became ill.
As viruses move between species, scientists fear they could evolve and easily spread not only from birds to mammals, but also from person to person.