Bird flu: How concerned should you be about human infection of H5N1? | Expert Answers | CNA Explains

Summary

Infectious diseases specialist Dr. Ooi Eng Eong discusses the potential threat of H5N1 bird flu to humans. He explains how the virus can jump from aquatic birds to poultry and possibly to humans, emphasizing the possibility of human-to-human transmission through a few mutations. While there's no current evidence of such transmission, the potential for a pandemic is real. The conversation covers symptoms, prevention, and the importance of public health preparedness, highlighting the lessons learned from COVID-19 in vaccine development and public health infrastructure.

Takeaways

• 🦠 Bird flu, specifically H5N1, is a concern because influenza has caused significant pandemics in the past.
• 🌊 The influenza virus is commonly found in aquatic birds and can be transmitted to poultry, causing mass deaths due to lack of adaptation.
• 🤝 Human-to-human transmission of bird flu is possible but has not yet occurred at alarming levels.
• 🔬 Research has shown that H5N1 could adapt to efficient human-to-human transmission with relatively few mutations.
• 🚫 Predicting the exact time or manner of such a mutation is not possible, and gain-of-function studies to explore this are ethically controversial.
• 🇸🇬 In Singapore, the risk of getting bird flu from food like milk, chicken, or eggs is minimal due to strict food safety controls by the Singapore Food Agency.
• 🍽️ When traveling outside of Singapore, it's advisable to avoid raw food to reduce the risk of contracting bird flu, as the virus is easily killed by heat.
• 🐦 The risk of contracting bird flu from birds at hawker centers is very low, as the viruses are primarily found in migratory aquatic birds.
• 🤒 Symptoms of bird flu in humans are similar to COVID-19, including sudden onset of fever and prominent respiratory symptoms like cough.
• 💊 There are drugs to treat influenza, such as Tamiflu, but no licensed vaccine for H5N1 exists yet, although early phase trials have been conducted.
• 🛡️ The experience from COVID-19 has improved our ability to quickly develop vaccines, particularly with mRNA technology, and has reinforced the importance of public health infrastructure and public engagement.

Q & A

What is the H5N1 virus, and why is it a concern for humans?

The H5N1 virus, commonly known as bird flu, is an influenza virus that primarily affects birds but has the potential to infect humans. It is a concern because influenza viruses have historically caused significant pandemics, and H5N1 has shown the ability to cross over from aquatic birds to poultry and, in some cases, to humans.

How does the H5N1 virus typically infect humans?

Human infections with H5N1 have mostly occurred through direct contact with infected poultry, particularly in large poultry farms. However, human-to-human transmission has not been a significant concern as of the time of the script.

Is it possible for H5N1 to be transmitted from one person to another?

Yes, human-to-human transmission of H5N1 is theoretically possible, and it may only be a few mutations away from being able to spread efficiently among humans. This potential makes it important to monitor and take the virus seriously.

What precautions can be taken to prevent the spread of H5N1?

Preventive measures include controlling the import of animals and food products, ensuring good food safety practices, and avoiding raw food, especially when outside of regions with strict controls like Singapore.

Can bird flu be transmitted through consuming food products like milk, chicken, or eggs?

In Singapore, the risk is minimal due to tight controls by the Singapore Food Agency. However, when traveling outside of Singapore, it is advised to be cautious about the origin of food products and to avoid raw food, as the virus is easily killed with heat.

What are the symptoms of bird flu in humans?

Symptoms of bird flu in humans are similar to those of COVID-19 and include fever, cough, and respiratory symptoms. In severe cases, it can lead to difficulty in breathing or shortness of breath.

Are there any differences in symptoms between adults, children, and the elderly?

Elderly individuals may exhibit non-specific symptoms such as increased fatigue and slightly elevated heart rate, while children typically present with fever, cough, and runny nose.

Is there a treatment available for bird flu?

There are antiviral drugs like Tamiflu that can treat influenza, but as of the time of the script, there is no licensed vaccine specifically for H5N1. However, vaccine development is possible if needed.

What is the difference between the H5N1 virus and the coronavirus?

The H5N1 virus is an influenza virus with 8 different RNA segments and two types of surface proteins ('H' and 'N'), leading to a wide variety of potential strains. In contrast, coronaviruses, like SARS-CoV-2, have a single-stranded RNA with multiple genes, making gene swapping less common.

How has the COVID-19 pandemic prepared us for potential future pandemics like H5N1?

The COVID-19 pandemic has accelerated vaccine development, particularly with mRNA technology, and has provided insights into public health infrastructure and response strategies. This experience should enhance our ability to respond to future pandemics.

What role does the public play in preventing and responding to a potential bird flu pandemic?

The public plays a crucial role in maintaining awareness of the risks, practicing good hygiene, and following health guidelines when a pandemic occurs. Engagement and education are key to an effective community response.

Outlines

00:00

🤒 Importance and Risk of Bird Flu Infection

The first paragraph introduces the topic of bird flu, or H5N1, and its potential threat to human health. Dr. Ooi Eng Eong, an infectious diseases specialist, discusses the historical impact of influenza pandemics and the possibility of bird flu infecting humans through contact with poultry. The conversation highlights that while human-to-human transmission has not yet occurred at alarming levels, it is possible and could be just a few mutations away. The segment also addresses the ethical concerns of gain-of-function studies and the importance of monitoring the situation closely. Additionally, it provides reassurance about the safety of consuming food products in Singapore due to strict import controls by the Singapore Food Agency (SFA), and advises caution when consuming raw food outside of Singapore.

05:04

💊 Understanding Bird Flu and Preparedness for a Pandemic

The second paragraph delves into the specifics of the H5N1 virus, including its genetic makeup and how it differs from the coronavirus. It explains the structure of the influenza virus, which has 8 different RNA segments and two types of proteins on its surface, leading to a vast number of potential virus combinations. In contrast, the coronavirus has a single-strand RNA with multiple genes, making it less prone to gene swapping. The paragraph also discusses the challenges of producing vaccines in advance due to their limited shelf life and the high costs of maintenance. The conversation turns to the lessons learned from COVID-19, emphasizing the rapid vaccine development capabilities, particularly with mRNA technology, and the importance of regional vaccine production. It concludes with the need for ongoing public health infrastructure readiness and public engagement to ensure preparedness for potential pandemics.

Keywords

💡H5N1

H5N1, commonly known as bird flu, is an infectious type of influenza virus that primarily affects birds but has the potential to infect humans. In the video, it is discussed as a possible cause for a future pandemic, highlighting the need for public awareness and preparedness. The term is used to emphasize the virus's zoonotic nature and its potential for human-to-human transmission.

💡Influenza

Influenza, often referred to as the flu, is a contagious respiratory illness caused by influenza viruses. The video script discusses the historical impact of influenza, causing significant pandemics, and its potential to cause future outbreaks. Influenza is central to the video's theme, as it sets the context for the discussion on bird flu and its implications for public health.

💡Zoonotic

Zoonotic refers to diseases that can be transmitted from animals to humans. In the context of the video, the H5N1 virus is highlighted as a zoonotic disease, primarily transmitted from aquatic birds to poultry and potentially to humans. The concept is crucial for understanding the origins of bird flu and the risks it poses to human populations.

💡Mutation

Mutation in the script refers to changes in the genetic material of a virus, which can potentially alter its characteristics, such as transmissibility and virulence. The video discusses the possibility of H5N1 mutating to a form that could be efficiently transmitted from human to human, emphasizing the unpredictable nature of viral evolution.

💡Pandemic

A pandemic is an outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population. The video raises the question of whether bird flu could become the next pandemic, indicating the global health concern and the importance of monitoring and preparing for such events.

💡Gain-of-Function Study

Gain-of-function study refers to research that aims to increase the transmissibility or virulence of a pathogen. The video mentions this in the context of ethical concerns, as such studies could potentially create more dangerous forms of viruses, like H5N1, which could pose a risk to human life.

💡Singapore Food Agency (SFA)

The Singapore Food Agency (SFA) is mentioned in the script as an organization responsible for ensuring food safety and security in Singapore. It is highlighted for its strict control over imported food products, which helps to mitigate the risk of bird flu transmission through food consumption within the country.

💡Ferret

In the script, ferrets are used as a model organism in research to study the transmission of H5N1. The researchers investigated how many mutations the virus would need to adapt to efficient transmission between ferrets, which serves as a proxy for potential human-to-human transmission.

💡Tamiflu

Tamiflu, mentioned in the video, is an antiviral medication used to treat influenza. It is brought up in the context of discussing the availability of treatments for bird flu, noting that while there is no licensed vaccine for H5N1, antiviral drugs like Tamiflu could be used in treatment.

💡mRNA Technology

mRNA technology is a method of vaccine development that uses a small piece of the virus's genetic code to stimulate an immune response. The video script highlights the rapid vaccine development capabilities enabled by mRNA technology, which was demonstrated during the COVID-19 pandemic and could be applied to future threats like bird flu.

💡Public Health Infrastructure

Public health infrastructure refers to the systems, resources, and services in place to protect and improve the health of a community. The video discusses the importance of a robust public health infrastructure in being prepared for and responding to potential pandemics, such as a bird flu outbreak.

Highlights

Influenza has caused big pandemics in the past and everyone should care about bird flu.

Influenza virus lives in aquatic birds which can carry the virus for a long time.

The virus has crossed over from aquatic birds to poultry in the past, causing mass poultry deaths.

Human-to-human transmission of bird flu is possible but has not occurred at alarming levels yet.

H5N1 may only be a few mutations away from efficient human-to-human transmission.

Gain-of-function studies to understand H5N1 mutations for human transmission are ethically unacceptable.

There is no way to predict when or how H5N1 may start spreading human-to-human.

In Singapore, getting bird flu from eating food like milk, chicken or eggs is not possible due to tight controls.

When traveling outside Singapore, avoid raw food to reduce bird flu risk as the virus is easily killed with heat.

The risk of getting bird flu from birds at hawker centers in Singapore is very minimal.

Symptoms of bird flu in humans are similar to COVID-19, including fever, cough, and respiratory issues.

Elderly may show non-specific symptoms like fatigue and slightly elevated heart rate with influenza.

Children with bird flu will exhibit typical symptoms like fever, cough, and runny nose.

There are drugs to treat influenza like Tamiflu, but no licensed vaccine for H5N1 yet.

Producing vaccines for H5N1 in advance is challenging due to shelf life and cost.

Influenza viruses have 8 different RNAs and two different proteins on the outside, unlike coronaviruses.

COVID-19 has taught us valuable lessons on vaccine development and public health response.

mRNA technology allows for rapid vaccine development, which is beneficial for future pandemics.

Governments and public health infrastructure should be prepared to respond to potential pandemics.

Engaging the population and raising awareness is crucial for effective pandemic response.

Transcripts

You've probably seen headlines about H5N1 or bird flu on

and off over the past few years, but could it infect humans?

And could we one day pass bird flu from one person to another?

And could it possibly be the next pandemic?

I'm Chan Eu Imm and this is Dr Ooi Eng Eong.

He's an infectious diseases specialist and today we're answering your questions

about bird flu.

Dr Ooi, do I need to care about bird flu?

I think the short answer is yes.

I think everyone should care about bird flu.

The reason is because influenza has caused big pandemics in the past.

Influenza virus lives in aquatic birds,

so these birds can carry the virus for a very long time.

Occasionally, where they perhaps land

or mix with farm animals, then what has happened in the past

is that the virus has crossed over from the aquatic birds to poultry.

And because the virus has not been adapted to poultry, they die in masses.

What are the chances of human-to-human transmission one day?

It is definitely possible.

So far, the human cases have mostly gotten it

from poultry because that's where the contact is, right?

Because the poultry farms are big.

Human-to-human infection hasn't occurred

at levels that would be of any alarm at all.

Years ago, there was this experiment done

where the researchers asked how many mutations,

does H5N1 need

to adapt to transmission from ferret to ferret,

and the answer is not that many.

So this thing that hasn't happened

is entirely possible.

And it may just be a few mutations away.

And that's why we need to take H5N1 seriously.

But there's no way to know when or how it will happen?

Unfortunately not.

Theoretically, you can use a gain-of-function study

to ask what mutations can allow H5N1 to spread efficiently

from human to human, but that is ethically unacceptable, right?

Because you are creating something that is of,

that puts human lives in danger when it actually doesn't exist just yet.

So unfortunately, the answer to your question is, we don't know.

But this is a space that everyone's watching closely.

Can I get bird flu from eating food like milk, chicken or eggs?

In Singapore, no.

Theoretically, it is possible but the Singapore Food Agency (SFA)

has a very tight control over what gets imported into Singapore.

And so for things like eggs and even fresh produce and all that, they send

SFA staff from Singapore out to these farms where they import food

from to ensure that good food security practices are always in place.

Now, when you travel out of Singapore, then do be aware of

the kind of checks on

where the food comes from and all that, may not be as good as in Singapore.

And so in general, just avoid raw food, when outside of Singapore

because the virus is easily killed with heat.

So if it's cooked, it's safe.

Can we get bird flu from birds at the hawker center?

I think the short answer is no.

The risk is very minimal.

The reason is because the viruses are mostly in the migratory aquatic birds.

So not so much in

the birds that we see around like sparrows and pigeons and all that.

What are the symptoms of bird flu in humans?

I think the symptoms will be quite

similar with COVID-19.

So obviously, I think the first one will be fever.

I think that will be quite prominent.

And sometimes very high fever. With influenza virus,

very often the the patient can even tell you

what time the fever started because it's a very sudden onset.

And then of course the respiratory symptoms, especially cough

will be very prominent.

And then, and that's when it's in the upper airway,

when it goes down to the lower airway, then you can get

difficulty in breathing or shortness of breath.

Does it differ between adults and children or maybe older adults like the elderly?

The elderly, at least for influenza, the disease can be very non-specific

in the sense that, the only sign that they are

unwell is maybe, they're more tired than usual.

And if you measure their heart rate, it is a little bit high, but that's it,

that's all they have until they get the severe form of disease.

And then they go down very quickly.

And children?

Children will get the fever and cough, of course. (Eu Imm) The usual.

Yeah, the runny nose and all that.

Is there any treatment available for bird flu?

There are drugs to treat influenza.

Tamiflu being probably the more famous one.

For H5N1, there's no vaccine that's been licensed yet, although I think

the companies have produced these vaccines in the past,

have done at least some early phase trials on it.

So they should be able to scale it up quite quickly.

The problem with producing the vaccine en masse

before the event is that every vaccine has a shelf life.

Then it becomes very expensive to upkeep these things,

especially when you don't know when it is going to happen

and whether it would happen.

Doctor, help us understand

the difference between the H5N1 virus and the coronavirus?

So influenza virus is a virus with 8 different RNAs

and the outside is decorated with two different proteins.

One is the "H", one is the "N".

And because there are 18 different "H" types and there are 11 different "N" types,

and so how many influenza viruses are there? It is 18 times 11.

So that's how many different influenza viruses there are.

Whereas in coronavirus, it is basically just one single strand of RNA inside.

There are multiple genes on that one single strand.

So in that sense it's more difficult for

coronaviruses to swap genes with one another.

Doctor, people are worried that this, H5N1, could be

the next big pandemic coming out of COVID-19.

Are we prepared? Has COVID-19 prepared us well?

We learned from COVID-19 that

we can make vaccines now quite quickly, especially with mRNA technology.

So it would be great to see that,

at least for the region, we have the ability to make these vaccines

for our part of the world, that we don't have to queue up to buy vaccines

from Europe or from North America.

So that's one.

I think two is that,

we've gone through COVID-19 and I think the government

has also gone through some exercise

to see what went well and what did not go so well.

So I think with those two things, we should at least

from the public health infrastructure, have the ability to respond.

And certainly,

we need to keep

engaging the population as well

so that they are aware of what they need to do when it does happen.

Okay, that's all we have for now.

We hope we've answered some of your questions.

If you have any more, drop them in the comments below and thanks for watching.