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What is the flu? -

The flu, also known as influenza, is an infection caused by a virus that affects the nose, throat, and lungs.

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When is flu season? -

In the US, flu season typically starts in October and lasts until late April. Additionally, the flu season consists of two types: influenza A and influenza B.

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When do you see type A and B flu? -

While the flu season can vary from year to year, in general, influenza A typically starts in autumn and really is in full swing by February. Then, come March, influenza B picks up and finishes out the season.

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What are the differences? -

Influenza A typically accounts for more cases of the flu when compared to type B flu. The symptoms in children also vary—type A usually results in more ear infections than influenza B.

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Who's at risk? -

The most important factor is that influenza B only infects humans while influenza A can infect birds and mammals. This is the explanation as to why antigenic shifts can occur in cases of influenza A but not B.

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Antigenic shift -

Antigenic shifts can happen when a bird or animal with influenza A transmits it to humans. This can result in pandemics because humans don't already have immunity to these viral serotypes or groups of viruses.

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Pandemic versus epidemic -

Influenza A and B can cause annual epidemics which are "declared when there are more cases of a specific disease than usual in a specific group of people." A pandemic, on the other hand, occurs when thousands or millions of people are affected by an epidemic in several different countries or even continents.

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The 2009 A/H1N1 pandemic -

Also known as the swine flu, the 2009 A/H1N1 pandemic infected millions worldwide and is an example of antigenic shift in action.

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Antigenic drift -

The other way the flu can evolve is through antigenic drift. With antigenic drift, the flu virus will make small changes known as genetic mutations annually. It's these mutations that account for the annual epidemics of flu that cause between 10 and 20% of the population to be ill.

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What do A and B have in common? -

Influenza A and B both spread the same way, cause similar symptoms, and are more likely to affect babies and older adults. Additionally, both types of flu are treated the same.

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How do you contract the flu? -

If someone who has the flu coughs or sneezes near you, or even talks to you, then you can contract the flu. An ill person expels small droplets when they talk, sneeze, or cough, which can enter your nose or mouth.

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Touch a contaminated surface -

If you touch a contaminated surface such as a counter, door handle, or phone, then touch your face, nose, mouth, or eyes, the virus can be transferred. 

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Touch someone's contaminated hands or face -

It's also possible to catch the flu if you touch the hands or face of someone who is contaminated with the flu and then touch your own face, nose, mouth, or eyes.

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Who is most vulnerable? -

While the flu can be caught by anyone, babies aged six months and younger as well as older adults are more likely to develop serious symptoms.

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Why babies? -

When germs such as the flu enter a child's body, their immune system then adds details about the virus to its 'database' and develops antibodies to protect against future attacks. Older children have usually experienced more sicknesses and have built up more antibodies. Babies, on the other hand, have not and are more vulnerable.

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Older individuals -

The flu can cause very serious complications in individuals aged 65 and older as they are more likely to have chronic diseases that can worsen with the flu.

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Flu symptoms -

Some of the common flu symptoms include headache, cough, chills, fatigue, muscle aches, runny or stuffy nose, congestion, and sore throat.

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Other symptoms -

Usually, only kids will have the possible symptoms of diarrhea or vomiting. 

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Treatments -

If you have a sudden onset of fever, cough, or headache it might be wise to call your doctor. This is especially true if you are immunocompromised.

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What to do if you have the flu? -

First and foremost, if you catch the flu, it's important to rest. Your body is working harder to fight off the flu so it's important to rest and relax so your body can recover.

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Eat well -

A hearty cup of chicken soup can warm your soul but try to eat foods that boost your immune system and help you fight the illness too.

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Drink fluids -

If you have a flu-induced fever, be sure you're drinking plenty of fluids, namely water, to help your body stay hydrated.

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Try heat -

Heat can help to ease your aching muscles. Try a warm shower or bath or try to use a heating pad or wrap.

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Stay home -

The flu is very contagious, so if you have it, stay home. This is especially true for the first three or four days after developing symptoms.

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Prevention -

Be sure to do your best to stay away from people with flu-like symptoms. If you work in a crowded space, be sure to be conscious about who you come into contact with.

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How to strengthen your immune system -

You can help keep the flu at bay by staying healthy, namely by eating well, staying active, and getting enough sleep regularly. 

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Avoid touching your face, eyes, and mouth -

As a rule of thumb, avoid touching your face, eyes, and mouth, especially if you have touched public surfaces recently and have not washed your hands.

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Wash your hands -

The final tip is to wash your hands regularly and use hand sanitizer. This will help kill germs that could easily be transferred.

Sources: (Cleveland Clinic) (Mayo Clinic)

See also: Why people cough long after healing from sickness

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