The United States’ Centers for Disease Control and Prevention (CDC) has issued a health alert after the first case of H5N1 avian influenza, or bird flu, seemingly spread from a cow to a human.

A farm worker in Texas contracted the virus amid an outbreak in dairy cattle. This is the second human case in the US; a poultry worker tested positive in Colorado in 2022.

The virus strain identified in the Texan farm worker is not readily transmissible between humans and therefore not a pandemic threat. But it’s a significant development nonetheless.

Some background on bird flu

There are two types of avian influenza: highly pathogenic or low pathogenic, based on the level of disease the strain causes in birds. H5N1 is a highly pathogenic avian influenza.

H5N1 first emerged in 1997 in Hong Kong and then China in 2003, spreading through wild bird migration and poultry trading. It has caused periodic epidemics in poultry farms, with occasional human cases.

Influenza A viruses such as H5N1 are further divided into variants, called clades. The unique variant causing the current epidemic is H5N1 clade 2.3.4.4b, which emerged in late 2020 and is now widespread globally, especially in the Americas.

In the past, outbreaks could be controlled by culling of infected birds, and H5N1 would die down for a while. But this has become increasingly difficult due to escalating outbreaks since 2021.

Wild animals are now in the mix

Waterfowl (ducks, swans and geese) are the main global spreaders of avian flu, as they migrate across the world via specific routes that bypass Australia. The main hub for waterfowl to migrate around the world is Quinghai lake in China.

But there’s been an increasing number of infected non-waterfowl birds, such as true thrushes and raptors, which use different flyways. Worryingly, the infection has spread to Antarctica too, which means Australia is now at risk from different bird species which fly here.

H5N1 has escalated in an unprecedented fashion since 2021, and an increasing number of mammals including sea lions, goats, red foxes, coyotes, even domestic dogs and cats have become infected around the world.

Wild animals like red foxes which live in peri-urban areas are a possible new route of spread to farms, domestic pets and humans.

Dairy cows and goats have now become infected with H5N1 in at least 17 farms across seven US states.

What are the symptoms?

Globally, there have been 14 cases of H5N1 clade 2.3.4.4b virus in humans, and 889 H5N1 human cases overall since 2003.

Previous human cases have presented with a severe respiratory illness, but H5N1 2.3.4.4b is causing illness affecting other organs too, like the brain, eyes and liver.

For example, more recent cases have developed neurological complications including seizures, organ failure and stroke. It’s been estimated that around half of people infected with H5N1 will die.

The case in the Texan farm worker appears to be mild. This person presented with conjunctivitis, which is unusual.

Food safety

Contact with sick poultry is a key risk factor for human infection. Likewise, the farm worker in Texas was likely in close contact with the infected cattle.

The CDC advises pasteurised milk and well cooked eggs are safe. However, handling of infected meat or eggs in the process of cooking, or drinking unpasteurised milk, may pose a risk.

Although there’s no H5N1 in Australian poultry or cattle, hygienic food practices are always a good idea, as raw milk or poorly cooked meat, eggs or poultry can be contaminated with microbes such as salmonella and E Coli.

If it’s not a pandemic, why are we worried?

Scientists have feared avian influenza may cause a pandemic since about 2005. Avian flu viruses don’t easily spread in humans. But if an avian virus mutates to spread in humans, it can cause a pandemic.

One concern is if birds were to infect an animal like a pig, this acts as a genetic mixing vessel. In areas where humans and livestock exist in close proximity, for example farms, markets or even in homes with backyard poultry, the probability of bird and human flu strains mixing and mutating to cause a new pandemic strain is higher.

The cows infected in Texas were tested because farmers noticed they were producing less milk. If beef cattle are similarly affected, it may not be as easily identified, and the economic loss to farmers may be a disincentive to test or report infections.

How can we prevent a pandemic?

For now there is no spread of H5N1 between humans, so there’s no immediate risk of a pandemic.

However, we now have unprecedented and persistent infection with H5N1 clade 2.3.4.4b in farms, wild animals and a wider range of wild birds than ever before, creating more chances for H5N1 to mutate and cause a pandemic.

Unlike the previous epidemiology of avian flu, where hot spots were in Asia, the new hot spots (and likely sites of emergence of a pandemic) are in the Americas, Europe or in Africa.

Pandemics grow exponentially, so early warnings for animal and human outbreaks are crucial. We can monitor infections using surveillance tools such as our EPIWATCH platform.

The earlier epidemics can be detected, the better the chance of stamping them out and rapidly developing vaccines.

Although there is a vaccine for birds, it has been largely avoided until recently because it’s only partially effective and can mask outbreaks. But it’s no longer feasible to control an outbreak by culling infected birds, so some countries like France began vaccinating poultry in 2023.

For humans, seasonal flu vaccines may provide a small amount of cross-protection, but for the best protection, vaccines need to be matched exactly to the pandemic strain, and this takes time. The 2009 flu pandemic started in May in Australia, but the vaccines were available in September, after the pandemic peak.

To reduce the risk of a pandemic, we must identify how H5N1 is spreading to so many mammalian species, what new wild bird pathways pose a risk, and monitor for early signs of outbreaks and illness in animals, birds and humans. Economic compensation for farmers is also crucial to ensure we detect all outbreaks and avoid compromising the food supply.

C Raina MacIntyre, Professor of Global Biosecurity, NHMRC L3 Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW Sydney; Ashley Quigley, Senior Research Associate, Global Biosecurity, UNSW Sydney; Haley Stone, PhD Candidate, Biosecurity Program, Kirby Institute, UNSW Sydney; Matthew Scotch, Associate Dean of Research and Professor of Biomedical Informatics, College of Health Solutions, Arizona State University, and Rebecca Dawson, Research Associate, The Kirby Institute, UNSW Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What’s the difference? is a new editorial product that explains the similarities and differences between commonly confused health and medical terms, and why they matter.

The terms “shyness” and “social anxiety” are often used interchangeably because they both involve feeling uncomfortable in social situations.

However, feeling shy, or having a shy personality, is not the same as experiencing social anxiety (short for “social anxiety disorder”).

Here are some of the similarities and differences, and what the distinction means.

How are they similar?

It can be normal to feel nervous or even stressed in new social situations or when interacting with new people. And everyone differs in how comfortable they feel when interacting with others.

For people who are shy or socially anxious, social situations can be very uncomfortable, stressful or even threatening. There can be a strong desire to avoid these situations.

People who are shy or socially anxious may respond with “flight” (by withdrawing from the situation or avoiding it entirely), “freeze” (by detaching themselves or feeling disconnected from their body), or “fawn” (by trying to appease or placate others).

A complex interaction of biological and environmental factors is also thought to influence the development of shyness and social anxiety.

For example, both shy children and adults with social anxiety have neural circuits that respond strongly to stressful social situations, such as being excluded or left out.

People who are shy or socially anxious commonly report physical symptoms of stress in certain situations, or even when anticipating them. These include sweating, blushing, trembling, an increased heart rate or hyperventilation.

How are they different?

Social anxiety is a diagnosable mental health condition and is an example of an anxiety disorder.

For people who struggle with social anxiety, social situations – including social interactions, being observed and performing in front of others – trigger intense fear or anxiety about being judged, criticised or rejected.

To be diagnosed with social anxiety disorder, social anxiety needs to be persistent (lasting more than six months) and have a significant negative impact on important areas of life such as work, school, relationships, and identity or sense of self.

Many adults with social anxiety report feeling shy, timid and lacking in confidence when they were a child. However, not all shy children go on to develop social anxiety. Also, feeling shy does not necessarily mean a person meets the criteria for social anxiety disorder.

People vary in how shy or outgoing they are, depending on where they are, who they are with and how comfortable they feel in the situation. This is particularly true for children, who sometimes appear reserved and shy with strangers and peers, and outgoing with known and trusted adults.

Individual differences in temperament, personality traits, early childhood experiences, family upbringing and environment, and parenting style, can also influence the extent to which people feel shy across social situations.

However, people with social anxiety have overwhelming fears about embarrassing themselves or being negatively judged by others; they experience these fears consistently and across multiple social situations.

The intensity of this fear or anxiety often leads people to avoid situations. If avoiding a situation is not possible, they may engage in safety behaviours, such as looking at their phone, wearing sunglasses or rehearsing conversation topics.

The effect social anxiety can have on a person’s life can be far-reaching. It may include low self-esteem, breakdown of friendships or romantic relationships, difficulties pursuing and progressing in a career, and dropping out of study.

The impact this has on a person’s ability to lead a meaningful and fulfilling life, and the distress this causes, differentiates social anxiety from shyness.

Children can show similar signs or symptoms of social anxiety to adults. But they may also feel upset and teary, irritable, have temper tantrums, cling to their parents, or refuse to speak in certain situations.

If left untreated, social anxiety can set children and young people up for a future of missed opportunities, so early intervention is key. With professional and parental support, patience and guidance, children can be taught strategies to overcome social anxiety.

Why does the distinction matter?

Social anxiety disorder is a mental health condition that persists for people who do not receive adequate support or treatment.

Without treatment, it can lead to difficulties in education and at work, and in developing meaningful relationships.

Receiving a diagnosis of social anxiety disorder can be validating for some people as it recognises the level of distress and that its impact is more intense than shyness.

A diagnosis can also be an important first step in accessing appropriate, evidence-based treatment.

Different people have different support needs. However, clinical practice guidelines recommend cognitive-behavioural therapy (a kind of psychological therapy that teaches people practical coping skills). This is often used with exposure therapy (a kind of psychological therapy that helps people face their fears by breaking them down into a series of step-by-step activities). This combination is effective in-person, online and in brief treatments.

For more support or further reading

Online resources about social anxiety include:

• This Way Up’s online program for managing excessive shyness and fear of social situations
• Beyond Blue’s resources on social anxiety
• a guide to looking after yourself if you have social anxiety, from the Western Australian health department
• social anxiety online program for children and teens from the University of Queensland
• inroads, a self-guided online program for young adults who drink alcohol to manage their anxiety.

We thank the Black Dog Institute Lived Experience Advisory Network members for providing feedback and input for this article and our research.

Kayla Steele, Postdoctoral research fellow and clinical psychologist, UNSW Sydney and Jill Newby, Professor, NHMRC Emerging Leader & Clinical Psychologist, UNSW Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.