Bird Flu May Have Come to Canada But it's No Reason to Panic | HuffPost

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Yesterday's announcement that the H5N1 avian flu had led to a death in Canada has taken public health officials -- and the general public -- by surprise. But while the revelation may signal the manifestation of many a fictionalized account of pandemics, the reality is that this is by no means a reason for panic.

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Microbiology, Health & Hygiene Expert

Microbiology, Health & Hygiene Expert

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Yesterday's announcement that the H5N1 avian flu had led to a death in Canada has taken public health officials -- and the general public -- by surprise. This is the first time that this particular strain of the influenza virus has appeared in North America and could suggest that a pandemic is not far away. The fact that this happened during a potentially remarkable flu season has made this concern even greater.

But while the revelation, headed no less by the Minister of Health, Rona Ambrose, may signal the manifestation of many a fictionalized account of pandemics, the reality is that this is by no means a reason for panic. By taking a look at the influenzaviruses and how H5N1 has emerged, the reasons for calm become evident.

Influenzavirus is a species, not unlike poliovirus and norovirus. Within the species are a number of strains, denoted by a numbering system developed back in the 1970s. There are collectively over 100 strains, each divided into major categories -- A, B, C -- and specifically for the A viruses, a further division based on the chemical nature of two proteins, hemagglutinin (H) and neuraminidase (N).

There are 16 different types of H and 9 varieties of N. The majority of these strains are avian in nature although some have adapted to humans. The most common human strains are H1N1 and H3N2, both of which lead to the annual flu season. For the most part, these viruses are not killers and only a very small percentage of people die from infection.

Back in 1997, one strain, influenza A H5N1, which was thought to be solely avian in nature, began to appear in people in Hong Kong. The outbreak led to 18 cases and six deaths, which suggested a 33 per cent mortality rate, far higher than anything seen since the Spanish Flu of 1918.

Microbiologists around the world took notice of the situation and watched to see if this was a long awaited pandemic. In this pre-SARS world, everyone was expecting a 'Big One' to crop up and this virus had all the markings.

There was, however, a problem with that prediction. While H5N1 had infected people, they were not in turn infecting others. Unlike H1N1, this flu wasn't being spread in the population, the so-called human to human transmission. This is a pre-requisite for a pandemic. With some searching and analysis, researchers learned that the individuals who contracted the disease had maintained close contact -- close enough to kiss -- with live birds or other infected people. The likelihood of a pandemic went from probable to minimal and soon, after a massive kill-off of birds, nil.

For most, that was the end of H5N1 but a small number of people feared the virus would return. Eventually, it did rear its ugly hemagglutinin in 2003; this time in Thailand and Vietnam. Another two dozen infections were recorded with 18 deaths. The mortality rate was higher yet the virus still hadn't figured out how to spread effectively between humans. As with Hong Kong, the outbreak was stopped although there was less confidence that it would be gone for good.

As with many stories that appear to have a nearing climax only to realize that it will never come, researchers never saw the 'Big One' they expected. Though research has attempted to determine the path to a pandemic, there has yet to be any concrete evidence that the virus will ever be a more than an occasional blip on the public health radar. A pandemic is unlikely.

In the meantime, H5N1 has spent the last decade circulating primarily in a few countries, such as Indonesia, Egypt, Vietnam, and China. It has infected some 650 people and killed close to 60 per cent of them. It's dangerous but only if you happen to come into that kissing distance with an infected bird, other known infected animals such as pigs and tigera, or an H5N1 infected human. For almost all Canadians, these are not part of routine activities.

Over the coming days and weeks, more information will emerge and eventually public health officials will understand how this virus happened to infect the unfortunate woman and lead to her untimely death. More likely than not, the picture will be comparable to most other H5N1 infections that have happened in the past: isolated and unable to spread widely. While tragic, this case is certainly not the same as the one in seen in the movie Contagion.

As much as it may seem heartless, from a purely microbial health perspective, there may even be some good news here. H5N1 has now traveled outside of its usual borders and not started a pandemic; it continues to be a rogue virus incapable of starting anything more than an isolated case or small epidemic. For microbiologists and epidemiologists, there is much to learn; for media, plenty to deduce. For everyone else, this case reveals the fact that the potential for a pandemic exists and that we all need to stay aware of -- but not panic about -- our relationship with germs.

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21 Facts About The Flu

Who Should Get The Flu Shot(01 of21)

Canada's National Advisory Committee on Immunization recommends that anyone over the age of six months who doesn't have a specific reason not to get a flu shot (previously having an allergic reaction to one) consider getting it. The average length of illness from the flu is seven days,which can be a major inconvenience for most people. And even healthy people can become quite ill. (credit:Shutterstock)

Who Really Needs It(02 of21)

There are some people who are at a higher risk for complications for the flu: people older than 65, pregnant women, children aged six months to two years, people with chronic diseases, and people who are otherwise immuno-compromised. The flu shot is especially important for these people, or those are in regular contact with a high-risk individual or group. People who live in nursing homes or chronic care facilities may also be more likely to be exposed to influenza, as are those who work with patients at high risk for contracting the disease. (credit:Shutterstock)

Who Shouldn't Get It(03 of21)

Those with egg allergies should be able to receive the inactivate flu vaccine without issues, but it's not known if the nasal vaccine is same for them. The new advice this year is that those with an egg allergy should be okay to get the vaccine, but should be observed for potential reactions, said Dr. Roth. Anyone who has ever had a severe allergic reaction to a previous flu shot, or contracted GBS within six weeks of a previous influenza vaccination, should speak with their doctor before getting the vaccine again. Also, the shot isn't given to infants younger than six months of age. And if you currently have a fever, wait to get your shot until it's gone, Dr. Roth said. (credit:Shutterstock)

What The Vaccine Protects Against(04 of21)

The flu vaccine protects against the three strains of the flu that researchers believe will be most common for that flu season, Dr. Roth explains. The flu shot, in general, is 70 to 90 per cent effective in preventing the flu in healthy kids and adults when the strains it contains match those in circulation. The vaccine is less effective for the elderly, though it can reduce the severity of symptoms for those who do contract influenza. (credit:Shutterstock)

What Is The Flu?(05 of21)

Influenza is a respiratory infection caused by influenza A and B, and is usually contracted in late fall and winter. The flu is spread by direct contact and the droplets expelled when we cough, sneeze, breathe or talk. Symptoms of influenza include the sudden onset of headache, chills, cough, fever, lack of appetite, sore muscles, fatigue, sneezing, watery eyes, runny nose, and sore throat. In children, the flu can also cause nausea, diarrhea, and vomiting. There are many strains of influenza, and the virus is mutating constantly. Having had the flu once before doesn't protect you from getting it again, because you could simply contract a different strain. (credit:Shutterstock)

What The Flu Isn't(06 of21)

Many people mistake a bad cold or other respiratory illness for the flu, but there is a difference. Influenza symptoms are generally more serious and include fever and muscle aches. Colds, caused by different bacteria or viruses, rarely result in serious illness, but it's possible to get pneumonia and other conditions as a result of the flu. Also, though we tend to refer to stomach illnesses as the stomach flu, they are not actually influenza instead, they are the result of other viruses or bacteria, or food-borne illnesses. The flu vaccine doesn't protect against colds or stomach viruses. (credit:Shutterstock)

Get Your Shot Early(07 of21)

It's recommended that you get your vaccine as early as possible. It takes about two weeks after vaccination for your body to develop the antibodies that prevent you from getting the flu, so getting the needle at the start of the flu season is the best way to avoid illness. Immunity varies by person but research has shown that the protection from your annual vaccine will last throughout flu season, even if you get the shot early. That said, if you didn't get an early shot, it's still worth getting vaccinated later in the year or even early into the next; flu seasons tend to peak in January and February, outbreaks are unpredictable and can last well into the spring. (credit:Shutterstock)

You May Be Asymptomatic(08 of21)

Though the flu can be miserable, you can also spread it without even realizing that you've been exposed. According to info from Harvard, 20 to 30 per cent of people carrying the influenza virus have no symptoms of the disease. (credit:Shutterstock)

We Need Herd Immunity(09 of21)

Herd immunity is the type of immunity that occurs when the vaccination of a significant percentage of a population provides protection against disease for those who are not or cannot be vaccinated or do not have immunity. Because most of a population have been vaccinated against a given disease, it's very difficult for that disease to spread because there are not many people who can actually become infected and pass it on. Getting vaccinated against the flu can help to work towards herd immunity and if the majority of members of a community are vaccinated against influenza, it will be harder for the disease to be contracted by those who cannot be vaccinated and don't have immunity. This is particularly important because it's often the case that those who can't be vaccinated are also at a higher risk of serious complications from the flu, for example, very young infants. (credit:Shutterstock)

How Many Shots?(10 of21)

For most people, the flu vaccine is given in a single shot. However, children who are aged six months to nine years and are getting the vaccine for the first time should receive two doses, four weeks apart. The nasal spray vaccination is also available in Canada, with a prescription, though it is not recommended for pregnant women due to lack of testing in that group. And elderly patients can receive a shot with an adjuvant that boosts their immune response. Dr. Roth said. (credit:Shutterstock)

Cost(11 of21)

Flu shots are free to all residents aged six months or older in Ontario and Alberta. In other provinces, some people are eligible for a free shot, and others will have to pay a small fee of $10 to $15. (credit:Shutterstock)

What It Includes(12 of21)

Each year, the flu vaccine offers protection against the three strains of the virus that researchers believe will be the most common that cold and flu season. Flu tends to move west to east, Dr. Roth explained, so researchers watch for common strains in other parts of the world to predict what will show up here when our flu season hits. So the shot does not protect against all strains of flu, but does offer protection from the ones you are most likely to encounter. The vaccine changes annually, which is why it's important to get your shot each year. (credit:Shutterstock)

Side Effects(13 of21)

In the vast majority of cases, the influenza vaccine causes only mild side effects, if any. The most common one is redness or soreness at the injection site. Some people get a headache or mild aches and tiredness if they get a vaccine that uses a modified live virus, like the nasal spray, or if they are getting the flu shot for the first time. In very rare cases, the flu can lead to Guillain-Barre syndrome, or GBS, which is a condition that leads to muscle weakness or paralysis. GBS is most common after infections, but may be associated with the flu in about one per million shot recipients. Recent research found that it's much more likely —thought still very rare — to get GBS from contracting the flu virus itself than from the flu vaccine. (credit:Shutterstock)

It Can't Give You The Flu(14 of21)

Many people report getting the flu shortly after getting a flu vaccine, and believe that the latter caused the former. But the flu vaccine cannot give you the flu, "It's impossible," said Dr. Roth. Most vaccines use dead viruses, and dead viruses can't make you sick. The FluMist nasal vaccine uses a live virus, but it has be specially engineered to remove the parts of the virus that can make you ill. In a study that compared people who got the flu shot with those who received a control shot of salt water, the only difference in symptoms was redness and soreness at the injection site for those who got the real vaccine. The flu vaccine is generally given during a time of the year when people are more likely to get illnesses like colds and flus; if you come down with something shortly after getting your flu shot, it's nothing but coincidence. (credit:Shutterstock)

You Can Get It While You're Pregnant(15 of21)

It is safe to receive the inactivated flu vaccine in any stage of pregnancy. "When you get sick with influenza and you're pregnant, the outcomes are worse," said Dr. Roth. Women in the second half of their pregnancies are at higher risk of hospitalization due to influenza, as are those at any stage of pregnancy who have a chronic medical condition. And having the flu when you are pregnant is particularly miserable because many of the medications you could otherwise take to relieve your symptoms are off limits. The flu vaccine is also safe for mothers who are breastfeeding. (credit:Shutterstock)

It Doesn't Contain Mercury(16 of21)

Thimersosal is a mercury-based preservative that has been the source of much controversy. It was previously used in some multi-dose vaccines, such as MMR, and a study by Dr. Andrew Wakefield linked it to autism. However, the study has since been fully retracted by the journal that published it, and its results have never been replicated by any other peer-reviewed medical research. There is no proof of a link between vaccines and autism. Single-dose flu vaccines do not contain thimerosal, whether they are given in the form of injection or nasal spray. (credit:Shutterstock)

The Flu Is Tough On Kids(17 of21)

We think of the elderly and sick as those most at risk from the flu, and while they can have serious complications, healthy people are not immune to the disease's effects. In particular, children with no pre-existing health problems can become seriously — even fatally — ill because of influenza. "I don't think we've gotten the message out very well about how important [the shot] is for children," Dr. Roth said. "Even healthy kids can die of the plain old flu." (credit:Shutterstock)

What About Swine?(18 of21)

Though protection for H1N1, colloquially known as swine flu, used to be given in a separate shot, this year's influenza vaccine includes the strain. It's important to re-up your protection for this disease, which can be quite serious, each year as it's not yet known how long immunity from the shot protects you against it. (credit:Shutterstock)

Universal Vaccine(19 of21)

Right now the flu vaccine changes annually to include the strains thought to be most common that year, but researchers are working on a universal flu vaccine that would protect against a wider number of strains of the virus. In September, researchers discovered that people who managed to avoid serious illness from the H1N1 swine flu had more virus-killing CD8 T cells in their blood during the pandemic in 2009. That discovery indicated that a vaccine that stimulates production of those immune cells could offer a more wide-ranging influenza protection and got us one step closer to a universal vaccine. (credit:Shutterstock)

What Won't Cure You(20 of21)

Antivirals like Tamiflu are effective against influenza, especially if taken within the first 48 hours of your illness. However, antibiotics do nothing to treat the flu, antibiotics fight bacteria and influenza is a virus. They may, however, be effective if you get a bacterial infection as a flu complication; if your symptoms get worse over time, or just won't go away, get checked out. The idiom "feed a cold, starve a fever" is not true. In both cases, you need to stay hydrated, and though the flu may kill your appetite you should take in as much nutrition as you can manage. (credit:Shutterstock)

Other Ways To Stay Healthy(21 of21)

Thorough and frequent hand-washing is your best defence against everyday illnesses like the flu. Here's a good rule of thumb: washing your hands for as long as it takes you to sing "Happy Birthday." Smoking makes people generally more susceptible to illness, so that's one more reason to quit (or not start). Covering your mouth with the crook of your elbow instead of your hands when you cough can help to prevent the transfer of germs. And if you are sick, stay home from work or school — you'll likely recover more easily if you rest, and you won't risk spreading it around. (credit:Shutterstock)

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