A dozen people in Cambodia are suspected of having been infected with the H5N1 bird flu strain tearing through the world’s avian population – sparking global panic about a spillover of the deadly virus to humans.
The 12 suspected cases are located in the same province as an 11-year-old girl who died from the infection Wednesday, raising fears the virus may be spreading from human to human for the first time in decades.
The Khmer Times – a local newspaper – reported that the suspected patients have all been tested for the virus and are waiting on lab confirmation, four of whom are symptomatic.
Several experts in America fear the close proximity of the cases may be a sign of human transmission after causing an unprecedented number of cases among the world’s bird population over the past year.
The virus has only ever been detected in around 870 cases, but around half resulted in death. In little over a year, more than 58million birds in the US and 200million globally have been culled to prevent its spread. In recent weeks it has been detected in mammals such as minks, foxes and sea lions.
This picture released by Cambodia’s Communicable Disease Control Department (CDCD) on February 23, 2023, shows villagers posing with posters about H5N1 virus threats, in Prey Veng province – where a girl died from the virus this week and 12 more are suspected to have been infected
A Cambodian man carries dead chickens at a market in Phnom Penh – the capital and most populous city of Cambodia
A young girl in Cambodia has died from the H5N1 bird flu. She was infected with the virus last week. She is the nation’s first case since 2014 (file photo)
Before the cases in Cambodia, only one case of H5N1 in humans had been detected this year. Cases in humans have been rare in recent years
The above map shows bird flu cases detected in poultry facilities (left) and in wild birds (right) in 2022 and 2023. The WHO has warned the world to prepare for a potential bird flu pandemic saying the virus could jump to humans
Dr Arturo Casadevall, an immunologist at Johns Hopkins, reacted to the suspected outbreak in Cambodia. He wrote on Twitter: ‘Key information is whether the 12 infected people obtained it from a bird source or from human-to-human transmission, which would be very worrisome.’
Dr Eric Feigl-Ding, an epidemiologist and Chief of COVID Task Force at the New England Complex Systems Institute, tweeted: ‘Hope this wasn’t human to human, but I’m now getting to be worried,’
H5N1 was first detected in chickens in Scotland in 1959, and again in China and Hong Kong in 1996. It first was detected in humans in 1997.
Human-to-human transmission of H5N1 is incredibly rare, but not impossible. In 1997, officials confirmed 18 H5N1 cases in Hong Kong, some of which were acquired through human-to-human transmission. The outbreak stayed relatively small, though. And did not spiral into a massive issue at either the local or global level.
This recent outbreak has caused particular concern. More than 15million domesticated birds, and countless wild animals, have been struck down by the virus. There is nothing to be done that can prevent the spread among wild birds, but officials are working to keep domesticated populations away from them. In the UK, all farmed chickens are now required to stay indoors.
While the virus is believed to be constantly circulating among wild birds, the massive swell of cases among domesticated birds has alarmed experts. Because domesticated birds often interact with humans, the risks of a spillover event are greatly increased.
Cambodian Health Minister Mam Bunheng warned that bird flu poses an exceptionally high risk to children who may be feeding or collecting eggs from domesticated poultry, playing with the birds or cleaning their cages.
The virus can spread to humans when a person has an open wound exposed to an infected bird. Usually, infections occur when a person is pecked or clawed by a bird. Transmission can also occur from a dead bird to a human.
World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus said the agency still deems the risk of bird flu to humans as low. ‘But we cannot assume that will remain the case, and we must prepare for any change in the status quo,’ he said earlier this month.
He advised people not to touch dead or sick wild animals and for countries to strengthen their surveillance of settings where people and animals interact.
Cambodia had 56 human cases of H5N1 from 2003 through 2014, and 37 of them were fatal, according to the World Health Organization.
Each person had samples were taken for analysis for a lab in Phnom Penh, the nation’s capital, around 40 miles west of the rural province of Prey Veng, where the suspected cases were detected.
It is unclear whether this group of people had any interaction with the 11-year-old girl, or if they come from the same part of the province. It is also unclear whether they had interactions with any birds that could be carrying the virus.
More than 1.1million people live in Prey Veng, it is the third most populous province in the country, and known to be densely populated.
Prey Veng is also were the girl who eventually died lived. She became ill on February 16 and was sent to be treated at a hospital in the capital
She was diagnosed last Wednesday after suffering a fever up to 39C (102F) with coughing and throat pain. She died shortly after her diagnosis, the Health Ministry said in a statement Wednesday night.
There are no treatments designed specifically for humans infected with bird flu, let alone H5N1. Those who fall ill are treated with regular antiviral drugs such as Zanamivir and Peramivir.
In case of an outbreak, the US does have a stockpile of vaccines designed to prevent infection from H5N1.
It is sold under the name Audenz and was approved in 2021 by the Food and Drug Administration for people six months and older. It is a two-dose vaccine.
Health officials have taken samples from a dead wild bird at a conservation area near the Prey Veng girl’s home, the ministry said in another statement Thursday. It said teams in the area would also warn residents about touching dead and sick birds.
Experts warn that the virus is adapting in ways that allow it to cause outbreaks in other mammals – increasing the risk it could spread among people.
In October, an outbreak of the bird flu ravaged a population of 52,000 mink at a farm in Spain.
Some of the critters were initially infected by eating meat from birds that died while infected.
There were also signs of mink-to-mink spread of the flu, which is unusual for a mammal population and signals a change to the virus.
In Peru, 716 sea lions were found to have died from the bird flu in recent weeks. Local officials worry that the virus has also spread between the animals – which are also mammals.
The world is suffering what has been described as the worst bird flu outbreak ever recorded, with over 58million birds in the US alone having been culled or killed by the virus over the past year.
The above map shows locations where there is a growing risk of a zoonotic virus outbreak. Dr Jennifer Nuzzo, a public health expert at Brown University in Rhode Island, warned that Texas was also a potential epicenter
Unlike usual spikes in bird flu that last months, this outbreak sustained itself through the summer of 2022 and is spread almost entirely by wild birds
For the US poultry industry the battle has been deadliest in history. The outbreak has ramped up pressure on the industry to protect its flocks and forced them to kill millions of birds to avoid the deadly spread.
To protect their domesticated birds, farmers around the country have installed extra protections from wild flocks, including installing vibrating mechanisms in containers holding chicken feed to avoid worker contamination.
The disease is so contagious that wind can carry bird droppings to a barn vent causing the virus to circulate inside.
It can also be spread to commercial flocks by workers stepping on wild-bird feces outside of a barn and spreading it inside with each step.
Some farms have installed motion-detecting alarms, known as ‘sound cannons’, as well as bright laser systems to shoo away wild birds without harming them.
The recent spread of the virus has lead to rampant inflation of both chicken and egg prices in the US and across the world.
Federal officials also fear that the spring migration of birds could also reignite spread of the deadly virus.
It comes as experts express greater fears of the threat of zoonotic diseases spreading in America. Last week, experts at Harvard University, in Cambridge, Massachusetts, and New York University, warned about the risks of zoonotic transmission.
In an editorial, they accuse the US of being too obsessed with external threats such as bioterrorism and lab leaks while failing to keep a close eye on the risks in its own backyard.
They called for an overhaul of regulatory agencies, including the US Department of Agriculture.
Experts have already warned that the next zoonotic outbreak could occur in China — because of its wet food markets — and Rwanda and Brazil — where urbanization and expanding agriculture are bringing people into contact with wild animals they would previously have been separated from.
But they also warn that Texas — one of the world’s leading producers of meat — could also be a hotbed for new dangerous viruses.
In the piece, they urged: ‘What is needed is not simply for agencies to do their jobs better or to paper over the gaps, but a fundamental restructuring of the way that human-animal interfaces are governed.
‘A One Health approach, which NBS-22 claims as its guiding principle, would take the health of other living things not merely as the occasional means or obstacles to human health, but as continuous with it.
‘The first step in implementing such an approach would be to create a high-level process for integrating the broken mosaic of multiple agencies, with their unclear and sometimes competing mandates, into an effective, comprehensive regime.’
Figures show 10billion animals were killed for meat in the US in 2022, the highest number on record and up 204million in 2021.
The country is also a leading importer of live animals — which could harbor diseases — bringing in about 200million annually according to estimates.
There is also a large wild game market which raises about 40million animals annually.
Scientists warned that infections could jump from animals to humans at any stage in the meat supply chain — from the rearing facility right through to slaughter and where it is consumed.
They warn there is a higher risk with live imported animals because these come into the US with no health and safety checks on arrival, meaning they could bring new diseases into the country.
There is also a higher risk with game animals, because these are not sanitized or regulated before being eaten.
Evidence is mounting that the US is already facing a growing number of animal-to-human infections.
The country recorded more animal-to-human infections in the second half of the 20th century than any other country globally, the scientists said.