Health Check: how long should you stay away when you have a cold or the flu?



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Symptoms of the flu generally develop more quickly and are more severe than the common cold.
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Nadia Charania, Auckland University of Technology

Most adults get around two to three colds a year, and children get even more. In terms of the flu, there are around 3-5 million severe cases of influenza worldwide each year and 290,000 to 650,000 deaths.

The symptoms of a cold and the flu are similar, so it’s hard to tell the difference. But the flu is usually more severe and develops more quickly than a cold.

Colds and flus can be easily passed from person to person through the air, when an infected person coughs or sneezes, and touch, when a person touches an infected surface or object like doorknobs and light switches.

So what’s the difference between colds and flus, and how long should you stay away?

Colds

Cold symptoms include a sore throat, cough, runny or stuffy nose, tiredness and headache.

Most people become contagious with cold symptoms one to two days after exposure to a cold virus. These symptoms usually peak two to four days later. The common cold usually lasts about ten days.




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There is nothing you can take to shorten the duration of a cold, and most people will get better without needing to see a doctor. But some over-the-counter medications can help alleviate the symptoms. These include anti-inflammatories (to reduce inflammation or swelling), analgesics (to reduce pain), antipyretics (to reduce fever) and decongestants (to relieve nasal congestion).

But be careful you follow the instructions and recommended dosage for these medications. A recent study of US adults who used paracetamol, the active ingredient in many cold and flu medicines, found 6.3% of users exceeded the maximum recommended daily dose. This mostly occurred during the cold and flu season.

For your own and others’ health, the best place for you to be when you’re sick is at home.
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Natural products such as vitamin C and echinacea are sometimes recommended to prevent and treat a cold, but there is limited evidence to support their effectiveness.

The flu

Common symptoms of the flu include fever (a temperature of 38°C or higher), cough, chills, sore throat, headache, runny or stuffy nose, tiredness and muscle aches.

An infected person can spread the flu for five to seven days after becoming infected. The infectious period can begin 24 hours before the onset of symptoms. This means you can spread the flu without even knowing you’re sick.

Influenza viruses can cause mild to severe illness in people of all ages. Most people will fully recover within one to two weeks and won’t require any medical attention. Similar to a cold, people can take some over-the-counter medications and other remedies to help alleviate symptoms.




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But some people can become acutely unwell with the flu. They may require antiviral medication and, in severe cases, hospitalisation. Those at high risk include pregnant women, children, the elderly, and people with certain medical conditions such as HIV/AIDS, asthma, diabetes and heart and lung diseases.

The flu virus strains that circulate usually change every year, so the best way to prevent getting the flu is to get the annual flu vaccine. The vaccine is moderately effective and recommended for adults and children over the age of six months. Some common side effects may occur, such as temporary soreness, redness and swelling at the injection site, fever, headache, muscle aches and nausea.

Wash with soap for at least 20 seconds to kill the germs.
Shutterstock/Alexander Raths

Avoid passing it on

If you feel unwell, stay home from work or school and rest (and get plenty of fluids) until you feel better. If you’ve had a fever, stay home for at least 24 hours after the fever has broken.

When you go back to work or school, you may still be infectious, so avoid passing the virus on by:

  • regularly washing your hands with soap and water for at least 20 seconds and drying them properly – if soap and water are not available, use an alcohol-based hand sanitiser

  • practising good cough and sneeze etiquette: cover your mouth and nose with a tissue or your upper shirtsleeve when you cough or sneeze, and throw away used tissues immediately

  • not touching your eyes, nose and mouth

  • The Conversationfrequently cleaning the surfaces and objects you’ve touched.

Nadia Charania, Senior Lecturer, Public Health, Auckland University of Technology

This article was originally published on The Conversation. Read the original article.

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A strong immune system helps ward off colds and flus, but it’s not the only factor



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Winter bugs are impossible to escape.
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Hui-Fern Koay, University of Melbourne and Jesseka Chadderton, University of Melbourne

It’s peak flu season. You’re cold, rugged up and squashed on public transport or in the lift at work. You hear a hacking cough, or feel the droplets of a sneeze land on your neck. Will this turn into your third cold this year?

No matter how much we try to minimise our exposure to respiratory viruses, it’s far more difficult in winter when we spend so much time in close proximity to other people.

On top of this, viruses tend to be more stable in colder and drier conditions, which means they stick around longer.




Read more:
Health Check: how long should you stay away when you have a cold or the flu?


The common cold is caused by more than 200 different viruses, the most common of which are rhinoviruses (rhino meaning nose). Rhinovirus infections tend to be mild; you might get a sore throat and a head cold lasting just a few days.

Influenza, or the flu, is generally caused by type A or B influenza viruses. The flu is far more aggressive and often includes a fever, fatigue and body aches, in addition to all the classic cold symptoms.

The flu tends to be more severe than the common cold.
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When it comes to getting sick, there’s always an element of bad luck involved. And some people, particularly those with young children or public transport commuters, are likely to come into contact with more viruses.

But you may have noticed that illness often strikes when you’re stressed at work, not sleeping properly, or you’ve been out partying a little too much. The health of our immune system plays an important role in determining how we can defend against invading cold and flu viruses.

How the immune system fights viruses

Your skin and saliva are key barriers to infection and form part of your immune system, along with cells in every tissue of your body, including your blood and your brain.

Some of these cells migrate around to fight infection at specific sites, such as a wound graze. Other cells reside in one tissue and regulate your body’s natural state of health by monitoring and helping with the healing process.

The cells that make up your immune system need energy too, and when you’re low on juice, they’ll be on low-battery mode. This is when our natural immune defences are weakened and normally innocuous bugs can begin to cause strife.

Our immune system requires a lot of energy to defend our bodies. Feeling tired and achy, overheating, and glands swelling are all signs that our immune system is busy fighting something.




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Boosting our natural defence system

Our immune system has evolved to naturally detect and eliminate viral infections. And we can actively strengthen our immunity and natural defences by looking after ourselves. This means:

  • getting adequate sleep. Sleep deprivation increases the hormone cortisol, which suppresses immune function when its levels are elevated

  • exercising, which helps the lymphatic system, where our immune cells circulate, and lowers levels of stress hormones

  • eating well and drinking enough water. Your immune system needs energy and nutrients obtainable from food. And staying well hydrated helps the body to flush out toxins

Good food feeds your immune system.
Anna Pelzer
  • not smoking. Smoking, or even secondary smoke, damages our lungs and increases the vulnerability of our respiratory system to infection.



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Educating our immune system

Natural defences aren’t always enough to keep us safe and we need the help of flu vaccinations.

Vaccines are designed to educate an army of B and T cells which make up your adaptive immune system. This arm of your immune system learns by exposure and provides long-term immunity.

These T and B cells need a bit of time from the initial influenza exposure before they can be activated. This activation lag time is when you feel the brunt of the flu infection: lethargy, body aches, extreme fatigue and unable to get off the couch for a day or two.

To overcome this delay and protect people before they are exposed to potentially harmful flu strains, flu vaccination introduces fragments of the influenza virus into the body, which acts like prior exposure to the bug (without actual infection).

You can still get the flu if you’ve been vaccinated but you might not get as sick.
VGstockstudio/Shutterstock

Seasonal vaccines are designed to match currently circulating strains and target those strains before you’re infected.

You can still catch the influenza virus if you are vaccinated. But because of this pre-education, the symptoms will likely be milder. The immune system has been trained and the army of B and T cells can move into action quicker.

Already have a cold or the flu?

If you’ve been sniffling and sneezing your way through winter, be comforted by the fact that these bugs are strengthening your immune system. Our body remembers the particular strain of rhinovirus or influenza we get, so it can recognise and mount a stronger defence if we encounter it again.


The Conversation


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Explainer: what’s new about the 2018 flu vaccines, and who should get one?


Hui-Fern Koay, Research Fellow in Immunology, University of Melbourne and Jesseka Chadderton, PhD Candidate, University of Melbourne

This article was originally published on The Conversation. Read the original article.