H5N1
How a 21-year-old Cambodian became the world’s latest bird flu victim


Sarah Newey
Thu, 21 December 2023 

Outbreak response teams burn the carcasses of infected chickens in Dang Tong province, Cambodia - Mech Dara

Chem Seavmey’s family are still in shock. One Sunday morning, the 21-year-old woke up slightly breathless, struggling with a fever and cough. A week later, she was dead.

“I did not expect this, it was so quick,” Chem’s brother-in-law, Sok Reth, told the Telegraph. “She just got worse and worse … Although the doctors tried to help, she still passed away. I am very, very regretful and sad … it was too quick for us.”

On November 26, at a hospital in the capital city three hours from home, Chem became the third person to die from bird flu in Cambodia this year. The country has seen a spike of infections after an eight year hiatus, with six of the 12 human H5N1 cases detected in 2023 reported here, according to the World Health Organization.


“Southeast Asia has always been a bit of a hotspot… but it’s hard to say why Cambodia has seen cases this year,” said Dr Bolortuya Purevsuren, an avian influenza expert at the World Organisation for Animal Health in Bangkok. “Any new human case is always a concern, wherever it unfolds.”

These cases hold crucial clues for scientists and health officials analysing pandemic threats. Tracing how Chem caught H5N1 can help sculpt strategies to reduce the likelihood of future spillovers, while scrutinising samples of the virus that killed her allows virologists to track how the pathogen is changing – and whether the threat to humans has risen.

“Will bird flu cause the next pandemic? Who knows,” said Dr Purevsuren. “But it’s critical to have strong surveillance to monitor trends in wild birds and poultry, quickly identify signals of cases in humans, and then investigate every one that is detected.”

Awareness campaigns have been limited in rural Cambodia, where poultry is critical for both income and sustenance - Mech Dara

It was infected poultry that passed H5N1 to Chem – a “gentle, quiet” person who loved reading and playing with her nieces and nephews – according to interviews with her family, local officials and epidemiologists.

The 21-year-old, who was also a keen cook, lived with her sister’s family in Dang Tong district in southern Cambodia, some 80 miles south of the capital Phnom Penh and close to the border with Vietnam.

In early November, ducks and chickens in Chem’s village suddenly started to drop dead. Unaware it was bird flu which killed them, eight of the families which lost poultry shared the carcuses with their neighbours to eat.

“They did not inform us about the deaths because it seemed normal to them,” said Ney Norn, a village leader. “They have not heard about [bird flu] for so long and do not pay attention to this disease, so they eat them.”
‘Heavily exposed to the virus’

Among those affected were Chem’s neighbours. While they buried the smaller birds, they kept and shared the larger chickens for food because they “did not want to waste them”, according to Chem’s brother-in-law, Mr Reth.

He’s not exactly sure when – Mr Reth and his wife often work in the capital Phnom Penh – but Chem was given, cooked and ate one of these chickens. Soon, she fell sick.

Initially, Mr Reth didn’t think much of it; Chem had a history of underlying respiratory issues. Usually “she got medicines and recovered quickly… but this time it was different”.

According to a WHO situation report, the 21-year-old developed symptoms including a cough, fever and shortness of breath on November 19. She was sent to hospital in the capital four days later as her condition deteriorated. There, she tested positive for H5N1.

“It is likely that she was heavily, heavily exposed to the virus,” said Professor Munir Iqbal, head of the Avian Influenza Virus group at the Pirbright Institute in the UK, who’s team sequence human samples from across the globe. “People are regularly exposed to H5N1, but cases where people become sick are still rare. Viral load is a significant factor.”

A public health awareness poster offers advice on hygiene - Mech Dara

Across the globe, 882 people have contracted H5N1 avian influenza since 2003, including 461 who died. For the last few years, human infections have actually been relatively limited – 2023 has seen the highest toll since 2016, though the total remains far lower than the 145 cases detected in 2015, a record high.

But for Chem’s family, the diagnosis was a shock.

“We had very difficult feeling and did not expect this disease because it has never happen in this area,” said Mr Reth.

“[Chem had] hesitated to go to hospital [because] she was afraid of needles… but then [when she arrived] the doctor told us that it is a very helpless situation, because the virus has eaten a large part of [the] anatomy of lungs. He [said he] would try his best to treat her [and] we spend everything to treat her.

“But since we arrive at the hospital, doctors could not help her. She died like we all fall asleep,” Mr Reth added. “We miss her … I am full of regret about losing [my sister-in-law].”

Chem was not the only person to catch the pathogen in the village; surveillance teams deployed after her positive test result found a four-year-old also infected. On November 25 the toddler – who had a fever, cough and rash – was sent to an isolated hospital ward for treatment.

Sim Han, the village chief, said the child’s family – who lived close to Chem – had been nervous about eating the sick poultry.

“But the kid was infected because after the mother had buried the chicken, the kid went to dig it up and played with it,” Mr Han said. “When the team asked the family, firstly they tried to hide it. But since the kid was also [in a] serious condition, they confessed it.”

The toddler is recovering, but the village is scarred.

“Now no one dares to eat [sick poultry], and they only bury or burn them,” said Mr Han.

So far in Cambodia this year, despite a major scare in February, there have been no signs of human to human transmission. Instead, experts say these cases and deaths reiterate the need to focus on public education – especially in rural regions and backyard farms.

“The cases all had contact with infected birds,” said Dr Purevsuren. “It shows the importance of biosecurity on commercial farms but also in backyard chickens.”

In Chem’s village, leaders said public awareness campaigns had taken place. But they have limits in rural Cambodia, where poultry is critical for both income and sustenance – culling initiatives can hit households hard.

“Often in our country when chickens get sick, [people] cook and eat them and it is fine,” said Toek Chat, a local police chief. “So some of our people are not worried about this… they [are] hesitant to cooperate with us to eliminate their chicken. It is very difficult for our people, because they do not want to kill their chickens.”

Since the village confirmed cases, though, there has been little opposition. Local health officials have sprayed disinfectant across the area, burned and buried hundreds of birds, and launched a renewed public health education campaign.

Others said the rapid detection and response also shows the surveillance system is working.

“We do not know why there is an increase in cases,” said Dr Filip Claes, a member of the Emergency Center for Transboundary Animal Diseases at the Food and Agriculture Organization, based in Bangkok.

“But it still happens around the major festivals in Cambodia, a time where we know the exposure to poultry increases,” he told the Telegraph. “Detection [and] surveillance systems [may] now be better at picking up cases.”

Across the globe, there have been concerns this year that the enormous recent outbreak in wild birds and poultry could provide new opportunities for the highly pathogenic H5N1 strain to mutate to better infect humans - especially because mammals from elephant seals in the Antarctic to mink in Spain have died.

But in Cambodia, it is a slightly older strain of H5N1 that has been circulating, said Prof Iqbal. And so far, analysis has picked up no signs that the virus has shifted to become more transmissible in humans.

“Current evidence does not show that the virus can infect humans, in Cambodia or elsewhere,” he said.

“But tomorrow? You never know, the virus may change. Which is why we have to report these cases and analyse these cases closely.”