What is the Flu? Symptoms to Look For
Fall is a beautiful time of the year. But, this season also brings something nasty with it: the flu.
There is no doubt, you have most likely experienced the flu several times, and it’s not much fun! But do you really know what the flu, or influenza, is?
Let’s begin with a brief history of the flu.
In 1918 there was a flu pandemic throughout the world. It started in the spring, with a mild wave. People experienced the flu symptoms we are used to now, such as fever and fatigue, and recovered after a few days.
Then, in the fall, a second wave of a highly contagious influenza appeared. This has since become known as the “Spanish flu” because Spain was one of the earliest countries hit hardest by the disease. When symptoms appeared, victims would die as quickly as a few hours or days afterwards.
This caused the average life expectancy in America to plummet by a dozen years! The estimated death toll of this pandemic is 20 to 50 million victims worldwide, but some estimates run as high as 100 million.[1] This pandemic had one particularly unusual feature, it mostly killed young adults, with 99% of pandemic influenza deaths occurring in people under 65.[2]
We have come a long way since then, with the first vaccine for influenza developed by Jonas Salk and Thomas Francis Jr in 1938. This was heavily funded by the army, and was used to protect the U.S. military forces against the flu during World War II[3]
According to the Centers for Disease Control and Prevention, “the flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat and lungs.”[4] The influenza virus is divided into four categories: A, B, C and D. The A and B viruses are what cause the influx of flu in the fall and winter whereas the C virus causes a mild respiratory illness and the D virus primarily affects cattle.[5]
We can feel sick for many different reasons, but how do you know when it is the flu? People can react to the flu differently, with some getting mildly ill and others getting severely ill.
The Government of Canada says that flu symptoms can include[6]:
- High fever (39°C and above)
- Cough
- Muscle aches
- Headache
- Chills
- Loss of appetite
- Fatigue (tiredness)
- Sore throat
- Runny or stuffy nose
- Stomach ache
- Diarrhea
- Nausea and vomiting
Symptoms usually start 1 to 4 days after exposure to the virus. Most people will recover within 7 to 10 days. However, the elderly, children and people with chronic illnesses are at greater risk of more severe complications.[7]
Make sure to look out for these symptoms as flu season approaches, and check out the Apex blog over the next few months to learn more about the flu!
If you are interested in an onsite flu clinic at your workplace, follow the link to visit our Fall Flu Clinic program.
Sources:
[1] http://www.history.com/topics/1918-flu-pandemic
[2] http://www.influenzavirusnet.com/history-of-influenza.html
[3] http://www.influenzavirusnet.com/history-of-influenza.html
[4] https://www.cdc.gov/flu/keyfacts.htm
[5] https://www.cdc.gov/flu/about/viruses/types.htm
[6] https://www.canada.ca/en/public-health/services/diseases/flu-influenza/symptoms-flu-influenza.html
[7] https://www.ontario.ca/page/flu-facts