After Covid breather, H5N1 bird flu threat looms on the horizon

At a time when the world in general, with few exceptions, has returned to near normality after the Covid-19 pandemic, it is a matter of concern that the threat of the H5N1 bird flu is looming on the horizon. The World Health Organisation (WHO) last Friday urged ‘heightened vigilance from all countries’ against bird flu. The latest trigger is the infection of the father of an 11-year-old Cambodian girl who recently died of the virus. Test results from 11 additional contacts of the girl were awaited. “We are really concerned about the potential human-to-human transmission coming from this initial spillover from animals,” said Dr Sylvie Briand, director of global infectious hazard preparedness and emergency preparedness for WHO.
A December WHO risk assessment of circulating H5N1 clade 2.3.4.4b viruses classified the risk to humans as ‘low.’ Briand said the WHO believes that level “has not changed,” given the Cambodian cases, “but we are really looking at this new information to see if we need to change the way we see things or not.” The clade of the Cambodian cases’ virus is currently unknown. H5N1 is “worrying, given the wide spread of the virus in birds around the world and increasing reports of cases in mammals, including humans,” she said while describing the virus as a “severe respiratory disease with a range of symptoms, from mild to fatal, with a mortality rate of over 50%,” she added.
The girl, from the southeastern province of Prey Veng, reportedly became ill February 16, suffering from a 102-degree fever, cough, and throat pain, according to a tweet from the Cambodian government. She died shortly after arriving at a hospital in the capital, Phnom Penh, the Associated Press reported, citing the country’s health ministry. It has not yet been determined how the girl or her dad was infected. But 22 chickens and three ducks at her home recently died, and there have been an unusual number of deaths among wild birds in the area as of late, BNO News reported, citing Cambodian government officials. It’s also unclear if the girl’s contacts who are experiencing symptoms had contact with birds.
If human-to-human transmission of H5N1 is confirmed in Cambodia, interventions like isolating cases, contact identification, and the use of antivirals after exposure can be used to prevent further spread among humans, Briand said. Disease surveillance can also be increased in areas that see such transmission, and in surrounding communities. And an attempt can be made to “control the source of the virus in the animal population, reducing the risk of spillover from animals to humans,” she added. “We are not there yet,” she said, referencing the need for such actions. But stakeholders at regional, national, and global levels are “starting to exchange information so everybody is aware of the risk and can very quickly react.”
Rajiv Chowdhury, senior epidemiologist and professor of global health at Florida International University, told Fortune that the illnesses in Cambodia “raise the concern that we are transitioning from what has been a bird-to-human status quo to more of a human-to-human transmission scenario.” Recent days have brought increased reports of H5N1 bird flu spreading among mammals throughout the world — a situation that must be “monitored closely” owing to their physiological similarities with humans, WHO Director General Tedros Adhanom Ghebreyesus said at a February 8 news conference.
H5N1 avian flu has infected millions of birds around the world this season. But it’s rare in humans and is almost always transmitted by direct contact with sick birds. Roughly 900 human cases have been reported over the quarter century it’s been known to exist, with no sustained transmission reported among humans. But “we cannot assume that will remain the case,” Ghebreyesus added.