In medical school, the professor who taught me about the flu shared what he considered to be the gold standard method of diagnosing a case of the virus: the £20 note test. The basic premise was that if someone said they had put a £20 note on the garden gate and it was yours for the taking, but you had to go and get it, a person with a real dose of flu would always pass up the reward in favor of staying in bed.
Apart from the fact that you may need an upgrade to £50 now to reflect the current feverish economic circumstances, it’s not a bad reminder of how the crappy flu can make you feel – and this year is no exception.
Why is the flu hitting so hard this year?
Health chiefs are warning that national flu figures have risen by 50% in a week and almost 3,000 people are being hospitalized with the infection, although this equates to only around 3% of NHS bed capacity.
The total number of flu cases we’re seeing is about the same as we tend to see at this stage of an outbreak as the flu tightens its seasonal winter grip on the country.
The difference this year, however, is that the epidemic seems to have started earlier, so we’re seeing higher numbers than we’ve historically had for November and December. Indeed, flu specialists agree that we are about two to three weeks ahead of where we are in a more normal year, when flu numbers tend to spike right after Christmas and into January.
What’s behind the early rise in cases?
There are several factors responsible for taking off earlier than usual. One is the arrival this year of a form of flu called H3N2. This is not unusual in itself. H3N2 is one of the common forms of the human flu virus, along with companions Flu B and H1N1, that circulate each winter. But the H3N2 form of the virus has not caused significant outbreaks in the UK for several years. This means that baseline immunity to H3N2 in most of the population is probably lower than normal, making more of us susceptible.
Then there’s the genetic curveball flu threw at us this year: During its migration here from the southern hemisphere’s flu season, H3N2 made a handful of genetic changes, or mutations, giving rise to the so-called “subclade K” variant. They have further “facelifted” the outer layer of the virus, making it even harder for our immune system to recognize it.
And, adding insult to injury, these genetic changes only appeared after the World Health Organization (WHO) had already decided what should go into the flu vaccine for this season, meaning the vaccines we’re giving are less well-matched to what’s circulating, so the H3N2 component may be less effective than we’d normally expect.
Less sunlight at this time of year means less ultraviolet (UV) light, and low humidity and lower temperature levels also mean virus particles tend to remain viable in the air and on surfaces for longer. So when we retreat indoors, slam windows and doors, huddle in cozy but poorly ventilated spaces, and exchange kisses under mistletoe, we’re much more likely to share our germs, especially if we’re more susceptible to infection to begin with.
How does the flu affect the body and what can you do to protect yourself and others?
The flu is a respiratory infection. Although it causes profound fatigue, fever, headache, and muscle aches and pains, the virus is usually limited to just the nose and throat and occasionally the lungs.
The symptoms throughout the body are actually caused by the immune system sending off alarm signals that put other tissues in an antiviral state in an attempt to control the spread of the infection.
Therefore, as a guide, a symptomatic person with a runny nose, headache and temperature is an infectious person, and with each breath they release clouds of viral particles into the air for others to inhale. A single cough or sneeze can release hundreds of infectious doses.
So if this is you, consider yourself a threat to others until the symptoms go away. Definitely don’t visit a care home or hospital to see a frail friend or relative, and if you are that friend or relative, ask anyone with symptoms to stay away until they get better.
If you’re unlucky enough to succumb to the flu, self-imposed isolation is the most effective way to stop the spread of the infection, so do everyone a favor and keep a low profile until you feel better.
The same goes for visiting your GP or accident and emergency departments.
How to manage symptoms
If you are normally healthy, flu can be managed safely at home with common sense, regular paracetamol, fluids and rest. Antibiotics will not help. It is the immune system that clears the flu infection. However, if you don’t get better after a few days, or if you develop new symptoms, such as a cough and a new fever, this could signal a secondary bacterial infection and you should seek advice.
The virus can also land on surfaces and remain active for a while, especially in cooler places, so when you’re out in public try to wash your hands regularly, avoid eating with your fingers, don’t bite your nails and try not to rub your eyes, all of which can carry virus particles where they need to be to infect you.
In general, prevention is always better than cure, and in this sense, the flu vaccine is the mainstay of our defense. Adults over 65 and those with chronic diseases, immune problems or in caregiving roles are given a free annual flu shot containing a mixture of the main circulating flu strains.
Some employers also provide this for their staff and flu shots can be purchased by those who want them at pharmacies and other specialist centers on the high street. Reassuringly, these shots don’t contain any live virus, so they can’t give you the flu, but it will take a few weeks to achieve maximum protection, so don’t delay. Vaccination leads to the production of antibodies that remain in the blood for several months while the flu is circulating, and they work normally about 60% of the time.
Why not 100%? Because the vaccine is a “best guess” at what scientists expect the flu to look like next season, and sometimes the vaccine is a poor match. That doesn’t mean it won’t work, though; a vaccinated person is still likely to have much less severe contact with influenza than if they were unvaccinated. They will also be protected against a brush with the other flu strains around that winter. So, in general, most people agree that it’s a good idea to take a jab and look forward to a flu-free Christmas.
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