Influenza virus probably originated in birds, and moved to people thousands of years ago when people began to domesticate fowl. Influenza, in other words, was an “emerging disease”, much like SARS today. Over the centuries, influenza epidemics have had dramatic effects on human populations. For example, the 1918 pandemic, is estimated to have caused some 50 to 100 million deaths, and influenza (and smallpox) devastated the first nations peoples of North America with the arrival of Europeans.

Pandemics Over the Years

One of the most striking features of influenza epidemics/pandemics is the impact of transportation. The pandemics that struck native North Americans were generated by the transfer of influenza across the ocean with the European invasion of this continent in the 15th century. In 1918, soldiers from North America carried a particularly virulent strain of the virus back to Europe on troop ships. Both the ‘Asian Flu’ of the 1950’s and the ‘Hong Kong Flu’ of the 1960’s were transferred across continents by human carriers. Epidemic, and in particular pandemic flu, in other words, is facilitated by transportation technology. The implications in today’s very highly connected world are obvious. Keeping your perspective on influenza is difficult. On one hand it is a major cause of death and illness; the “smaller” Asian and Hong Kong epidemics in the 50’s and 60’s killed perhaps 1 million people globally each. To put that in perspective, the 9/11 attacks killed less than 3,000.

Death from Influenza

From a public health point of view, influenza is a big, big deal. On the other hand, while death numbers are staggering, death rates from influenza are small, particularly among those who are not very young, very old, or chronically unwell. The usual flu mortality rate is 1 in 1000, and this includes all those at particular risk. For those not usually at risk (a healthy child or young adult, for example), influenza death rates are vanishingly small. On the other, other hand (what is this, three hands now?) the 1918 pandemic had a mortality rate of 2 to 20%, and appeared to specifically target young adults. But (fourth hand) most of these deaths were due to secondary bacterial pneumonia, and we can treat that a lot better now than we could 90 years ago.

What any of this will mean during the next flu pandemic is anyone’s guess. It really depends on the characteristics of the particular viral strain involved. Will it be closer to Hong Kong flu, or will it more closely resemble the 1918 monster? While we can make some educated guesses at this point, the bottom line is that we will have to wait and see. Fortunately, for the western world, there are usually clear indications weeks to months prior to the arrival of influenza, and current surveillance provides severity data before the flu hits. So this won’t be something that springs out of your child’s daycare without warning.

Managing Influenza

Those of you who have read my approach to fever will know that I place a lot of value on the “Looks Great Test”, which says, basically, that if your child looks wonderful after pain and fever medication, the chance that your child has a dangerous infectious disease is quite small. I still think that this is true in the context of influenza, but there is a catch: Kids with true influenza frequently don’t pass the “Looks Good Test”.

Influenza is a viral tiger. It often settles in the lungs, rather than the upper respiratory tract, and this means that even when the fever and pain are gone, the body is still functioning under a significant impairment. Children with the flu are often lethargic, breathing rapidly, with higher heart rates even after acetaminophen or ibuprofen.

So when you come into the emergency department in flu season, expect to be told by the triage nurse that your child should wait to see the doctor, and then expect to wait. There will be a lot of others there with you. Never has the strategy of booking an appointment with your family doctor been a better idea. If you have the luxury of having a family doctor who can fit you in during flu season, I strongly advise you to go that route. If, of course, your child is frightening you, then forget that, and come straight to the emergency department.

So what are we going to tell you to do? Well:

• Drink lots
• Sleep lots
• Take fever and pain medication as needed (NOT ASPIRIN)

I know, it seems pretty inadequate to us too.

There are medications that directly attack the flu. Amantadine and zanamivir are two examples. If the influenza virus you have is Influenza A, and if you get the drugs within 48 hours of the first symptoms, available evidence suggests that your child can reduce the duration of symptoms by about one day. Not a big help, and you have to be lucky to identify the flu fast enough to get the drug.

Further, in 2005-2006, resistance to some of these medications was becoming widespread. We don’t know what that means for the future, but over-using these drugs will almost certainly increase this problem. The bottom line is that these drugs should be reserved for those people who have serious risks from this illness, and should not be used for those of us who feel miserable but aren’t at particular risk. Each time one of us uses these drugs, we are diminishing the benefit they hold for other, more seriously involved patients. If you are an otherwise healthy person with the flu, and you are having problems believing that ANYONE needs drugs more than you do, I understand, believe me. But, with the greatest empathy in the world, suck it up, princess.

One critical aspect, though, is to know that it is influenza that is making your child sick and not some other, more serious illness. The common symptoms are:

• Sudden onset of fever, often with chills
• Headache
• Muscle aches
• Cough, initially dry but becoming more prominent
• Subsequent sore throat, runny nose, and sometimes red eyes, abdominal pain, vomiting and diarrhea

So influenza can look very much like other, more serious conditions. Fever and sore throat can be strep throat. Fever, cough and headache are very frequent findings in bacterial pneumonia. Similarly, fever, headache and vomiting are findings consistent with meningitis. Bottom line: you often need to see a doctor in order to know that these more serious conditions have been ruled out. And your doctor may need to do some tests (generally an x-ray, sometimes bloodwork) to help resolve the issue.

Otherwise, managing influenza is just like managing any other fever. Concentrate on the appearance and behaviour of your child, not on how high the fever goes. Trust yourself; if you see your child becoming more lethargic, or more irritable, or developing some new or more aggressive symptoms, see a doctor. And wash your hands, every time you think about it.

Avoiding the Flu

Here’s a thought; since treating the flu is difficult, how about avoiding it all together?

Influenza vaccines are offered annually because the virus mutates so often that immunity this year just doesn’t confer any protection to next year’s virus. Recent studies suggest that overall vaccines can reduce your risk of getting “true influenza” by about 2/3. “True” influenza is that which can be confirmed by laboratory tests, and is differentiated from “clinical” influenza or “influenza – like illness” (“ILI”). Against these latter categories, influenza might decrease the rates of by as little as 1/3. Studies on children under two years of age are too rare to comment on. So, vaccinating against influenza is not a magic bullet; there is still a substantial risk of still becoming sick even when you get shot. However, there is some suggestion that rates of ear infections fall by half for those who are vaccinated against influenza, and that hospitalization and secondary pneumonia rates fall as well.
What are the risks? All interventions have risk. Deciding to immunize your child involves pain at the injection site, and a chance that a blood vessel will be injured resulting in a painful swelling (a hematoma) that will last for a few days. Some children have low grade fever and some muscle aches after the injection. Rare complications include Guilliane Barre syndrome.

Remember, though, that deciding not to immunize is also an intervention….it is just a negative one, and it has risks as well. There are children for whom an attack of influenza is particularly risky; the chance of prolonged illness, hospitalization or even more serious consequences have to be weighed against the (usually) trivial common complications of the flu shot, and against the rare, more serious ones as well.

Finally, some people believe that it is “better” to “beat the flu by yourself” because your “immune system gets stronger” if you do. I think that is nonsense. Your child’s immune system really doesn’t care whether the viral fragment that it reacts to is part of a live virus that has been disabled and injected into you, or part of a live virus that you caught from sucking on contaminated lego. The protection afforded by immunization has the distinct advantage of not requiring you to get the disease! Not everything “natural” is better.

 

Immunization for the Flu

Well, the American Academy of Paediatrics, seemingly not hampered by absence of evidence, recommends that all healthy children, including those under 2 years of age, be routinely vaccinated for influenza. I don’t agree. The analyses I have read consistently state that the amount of study in this area is inadequate to make blanket statements. However, there are children for whom an attack of influenza is much more likely to result in hospitalization, and even a risk of serious consequences. These are the kids with significant asthma, cystic fibrosis and other chronic lung diseases, or with heart disease, chronic kidney disease, cancer and certain blood diseases, or problems with immunity. Basically, anyone with (or living with someone with) a chronic illness of any kind should ask their doctor whether they should be vaccinated. In addition to this list, those children with very frequent ear infections, for whom surgery (tubes) are being considered should at least discuss the idea of flu vaccine with their doctors. So should people who care for high risk individuals (doctors, nurses, paramedics, teachers, daycare workers…).

Essentially, immunization doesn’t guarantee a thing. Immunizing everyone is at best controversial; in particular there just isn’t enough evidence for me to comment on the routine use of the flu shot in healthy children under two years of age. Immunization probably reduces the risk of infection, and if getting the flu is something you dread, or if you or your family members have a chronic illness that heightens your risks, then go get shot.

Bottom Line
Here it is, the line that will get me a nasty email from any public health worker that reads it: Influenza gets a bad rap these days.

We live with media that, despite the intentions of its often honourable workforce, informs us with fear rather than reason. So we tend to focus on the fact that a million deaths can be attributed to even a relatively small global outbreak, like the Hong Kong flu, rather than the fact that those million deaths came from a denominator of roughly 2 billion people infected. The risk of death per person is very, very small, at least among the low risk groups. When a child gets influenza, he and his parents are in for a rough week, maybe more, with fever, cough, aches and pains, sleepless nights and a high general ‘yuck’ factor. Frustating? Sure…. but fear is not usually warranted.

There are times to worry, of course. If you aren’t sure your child has influenza, then be seen by a doctor to get him checked out. If your child or someone in your family has any kind of chronic disease, put a big ‘X’ through the first of October on your calendar, so that you remember to ask about getting vaccinated. If your child seems to just keep getting worse (fails “Looks Great Test”) then don’t sit at home, get your child seen! Finally, when the next flu pandemic hits, it may well be that careful consideration by public health officials will reveal that we have to be concerned, and that special measures may be needed.

But, for now, with pandemic flu not immediately on the horizon, the best advice is to avoid people who are sick if possible, and if that fails, take your liquids and fever meds and rent a dozen good movies.

Brett Taylor is an emergency pediatrician, an associate professor of pediatrics and emergency medicine and a masters candidate in health informatics based in Halifax, Nova Scotia, Canada.  

See also our article on colds and flu during pregnancy.