Influenza (the Flu) is a common and highly contagious respiratory illness caused by influenza viruses. It causes infection of the nose, throat and lungs. It can be one of the most severe illnesses of the winter season. It can cause mild to severe illness, and at times lead to death. While most healthy people recover from the flu without complications, some people, such as older people, young children, and people with certain health conditions, are at high risk for serious complications from the flu.
What are the Signs and Symptoms of the Flu?
The flu usually starts suddenly and may include the following symptoms:
- Fever (usually high)
- Headache
- Tiredness
- Cough
- Sore throat
- Runny/stuffy nose
- Generalised body aches and pains
- Diarrhoea and vomiting can also occur (commoner in children)
These symptoms are referred to as “flu-like symptoms”. A lot of different illnesses, including the common cold, can have similar symptoms.
What are the risks and complications of Influenza?
Some complications caused by the flu include:
- Bacterial pneumonia
- Dehydration
- Worsening of chronic medical conditions such as congestive heart failure, asthma, diabetes
- Sinus problems
- Ear infections
Who is most at risk of Complications?
- People aged 65 years and older
- Children aged less than 2 years
- Women more than 3 months pregnant during the flu season
- People with underlying chronic conditions (e.g. Asthma or other lung disease, diabetes, heart disease, kidney disease, blood disease or immune disorders)
- Residents of nursing homes and other long-term care facilities that house persons of any age who have long-term illnesses
- Children and teenagers (aged 6 months – 18 years) who are on long-term aspirin therapy and therefore could develop Reye syndrome after the flu
Since 2000, a flu shot has been recommended for all people aged 50–64 years old each year.
How is it spread?
The Flu spreads in respiratory droplets hence it usually spreads from person to person when an infected person coughs, sneezes or talks and the virus is sent into the air. Occasionally a person may become infected by touching a recently contaminated surface, such as a doorknob, telephone or computer keyboard, and then touching their eyes, nose or mouth.
An adult who has the flu may be contagious 24 hours before he/she develops symptoms and during the 7 days after onset of symptoms. Children can start shedding the virus from 6 days before getting symptoms and can continue up to 14 days after onset of symptoms or 21 days if immunocompromised.
How can one avoid getting the Flu?
Good Health Habits are important. These include:
- Covering nose and mouth with a tissue when coughing and sneezing
- Throw the tissue away in a waste-paper basket
- Washing hands often with soap and water (or alcohol-based hand cleaner), especially after coughing or sneezing
Stay away as much as you can from people who are sick.
- If you get the Flu, stay home from work or school.
- Do not go near other people so as not make them unwell too.
Vaccination: Another important way of preventing the Flu is by getting a Flu vaccine at the beginning of every autumn.
Medication: Antiviral medications (amantadine, rimantadine and oseltamivir) are approved for use in preventing the flu. These are prescription medications, and a doctor should be consulted before they are used.
Hand washing
Why is hand washing important?
By frequently washing your hands you wash away germs that you have picked up from other people, or from contaminated surfaces, or from animals and animal waste.
If you do not wash your hands frequently you pick up germs from other sources and then you infect yourself when you touch your eyes, your nose or your mouth.
You can also spread germs directly to others or onto surfaces that other people touch. And before you know it, everybody around you is getting sick!
When should you wash your hands?
You should wash your hands often. Probably more often than you actually do because germs cannot be seen with the naked eyes, nor can they be smelt, so you do not really know where they are hiding.
It is especially important to wash your hands:
- Before, during and after you prepare foods
- Before you eat
- After you use the bathroom
- When your hands are dirty
- More frequently when someone at home is sick
- After handling animals or animal waste
What is the Correct Way to Wash Your Hands?
- Wet your hands and apply liquid or clean bar soap. Place the bar of soap on a rack and allow it to drain
- Rub your hands vigorously together, scrubbing all surfaces
- Continue for 10-15 seconds – the soap combined with the scrubbing action helps dislodge and remove germs
- Rinse well and dry your hands
The Influenza Vaccine
Influenza vaccines have an excellent safety record and have proven highly effective in preventing illness and serious compilactions among the elderly, healthy younger adults and children. A lot of illness and death caused by the Flu can be prevented by a yearly flu vaccination. Vaccination of the elderly (60+) reduces hospitalization for pneumonia and influenza on average by 33% and reduces all-cause mortality by 50%. People in certain groups who are at high risk to develop serious complications from the Flu and people who are in close contact with those at high risk should get vaccinated every year. It is also economically beneficial as it reduces medical costs and work absenteeism.
The “Flu shot” – an inactivated vaccine, that contains killed virus. This is given with a needle, usually in the arm. It is approved for use among people over 6 months of age, including healthy people and those with chronic medical conditions.
The vaccine contains 3 influenza viruses, representing one of the three groups of viruses circulating among people in a given year. Each of the three vaccine strains in both vaccines - one A (H3N2) virus, one A (H1N1) virus, and one B virus – are representative of the influenza vaccine strains recommended for that year. Viruses for both vaccines are grown in eggs.
How does it work?
It causes antibodies to develop in the body, and these antibodies provide protection against influenza virus infection.
Why should people get vaccinated against Influenza?
Influenza is a serious disease that can affect people of any age. During the “Flu season” – October to May – Flu viruses are circulating in the population. An annual Flu vaccine is the best way to reduce the chances of getting the Flu.
When should I get a flu vaccine?
The best time is at the beginning of October, though you can still benefit from getting vaccinated even if you take it later.
Does it work straight away?
No it does not. It takes between 4-6 weeks after vaccination for antibodies to develop in the body and provide protection against the influenza virus. In the meantime you are still at risk of getting the Flu. This is why it is better to get vaccinated early, before the Flu season gets under way.
Can I get the flu even though I got a flu vaccine this year?
Yes. The ability of the Flu vaccine to protect a person depends on two things:
- the age and health status of the person getting the vaccine, and
- the similarity or “match” between the virus strains in the vaccine and those in the circulation.
Why do I need to get vaccinated against the flu every year?
Flu viruses change from year to year. This means that, first of all you can get the Flu more than once during your lifetime. The immunity (natural protection that develops against a disease after a person has had that disease) that is built up from having the Flu caused by one virus strain doesn’t always provide protection when a new strain is circulating. Secondly, a vaccine made against Flu viruses circulating last year may not protect against the newer viruses. That is why the Influenza vaccine is updated to include current viruses every year.
Another reason to get the Flu vaccine every year is that after you get vaccinated, you immunity to the disease declines over time and may be too low to provide protection after one year.
How are the viruses for the flu vaccine selected?
Each year many laboratories throughout the world collect Flu viruses. Some of these viruses are sent to one of four World Health Organization (WHO) reference laboratories for detailed testing. These laboratories also test how well antibodies made to the current vaccine react to the circulation virus and new Flu viruses. This information, along with information about Flu activity, is summarized and presented to an advisory committee of the U.S. Food and Drug Administration (FDA) and at a WHO meeting. These meetings result in the selection of three viruses to go into Flu vaccines for the following autumn and winter. Usually, one or two of the three virus strains in the vaccine are changed each year.
Who Should Get the Influenza Vaccine?
All people at high risk (as mentioned previously) should be vaccinated against Influenza.
People who can give the Flu to others at high risk for complications should also get vaccinated. These include:
- doctors, nurses and other employees in hospitals and doctors’ offices, including emergency response workers
- employees of nursing homes and long-term care facilities who have contact with patients or residents
- employees of assisted living and other residences for people in high-risk groups
- people who provide home care to those in high-risk groups
- household members (including children) of people in high-risk groups
Who should not get the Influenza vaccine?
People in the following groups should not get the Flu vaccine before talking with their doctor:
- People who have a severe allergy to hens’ eggs
- People who have had a severe reaction to a Flu vaccine in the past
- People who previously developed Guillain-Barré Syndrome (GBS) in the 6 weeks after getting the Flu shot.
What about the General Population, Pregnant Women and Breastfeeding Mothers?
The General Population: Most people who want to lower their chances of getting the Flu can get vaccinated. People who provide essential community services (e.g. police, firemen) should consider getting vaccinated to minimize the disruption of essential activities during Flu outbreaks. Vaccination is encouraged for students or others in institutional settings (e.g. Those who reside in dormitories). Vaccination of healthy adults reduces the morbidity rate by 65% on average. This is also cost saving to society.
Pregnant Women: Pregnancy can increase the risk for complications from the Flu, and pregnant women are more likely to be hospitalized from complications of the Flu than non-pregnant women of the same age. In previous worldwide outbreaks of the Flu (pandemics of1918-19 and 1957-58), deaths among pregnant women were associated with the Flu. Pregnancy can change the immune system in the mother, as well as affect her cardiovascular system (heart and lungs). These changes may place pregnant women at increased risk for complications from the Flu.
Because the Flu shot is made from inactivated viruses (the viruses are killed), many experts consider Flu shots safe during any stage of pregnancy. However, since miscarriages (spontaneous abortion) most often occur in the first trimester of pregnancy, experts have traditionally not given a Flu shot during the first trimester to avoid a coincidental association with miscarriage.
Women who will be beyond the first 3 months of pregnancy during the Flu season should get a Flu shot. Pregnant women who have medical problems that increase their risk for complications from the Flu should get a Flu shot before the Flu season, no matter their stage of pregnancy.
Breastfeeding Mothers: It is safe to get the Flu vaccine if you are breastfeeding.
Does the vaccine cause side effects?
Vaccination may cause a local reaction (soreness) at the injection site, and, less often, temperature and aching muscles for a couple of days.
Can the flu be diagnosed?
There are tests that can determine if you have the Flu as long as you are tested within the first 2 or 3 days of illness. Also, a doctors’ exam may be needed to tell whether you have another infection that is a complication of the Flu.
What do you do if you get sick?
There are steps you can take if you get sick with the Flu:
If you get the Flu, get plenty of rest, drink a lot of liquids, and avoid using alcohol and tobacco. Also, you can take medications to relieve the symptoms of the Flu (but never give aspirin to children or teenagers who have flu-like symptoms, particularly fever).
If you are at high risk of developing the Flu, you should consult your health-care provider if you develop flu-like symptoms. Your doctor may recommend use of an antiviral medication to help treat the Flu.
Antiviral Medications
Three antiviral drugs (amantadine, zanamavir, and oseltamivir) are approved for treatment of the Flu. These are prescription medications, and a doctor should be consulted before the drugs are used. Antiviral treatment lasts for 5 days and must be started with 48 hours of developing symptoms in order for them to be affective.
Who requires urgent medical attention?
There are some “emergency warning signs” that require urgent medical attention:
- In children, emergency warning signs include:
- Fast breathing or having trouble breathing
- Bluish skin colour
- Not drinking enough fluids
- Not waking up or not interacting
- Being so irritable that the child does not want to be held
- Flu-like symptoms improve but then return with fever and a worse cough
- Fever with a rash
In adults, emergency warning signs include:
- Difficulty breathing or shortness of breath
- Pain or pressure in the chest or abdomen
- Sudden dizziness
- Confusion
- Severe or persistent vomiting
Seek medical care immediately! Call your doctor or go to an emergency room if you or someone you know is experiencing any of the above signs. When you arrive, tell the reception staff that you think you have the Flu. You may be asked to wear a mask and/or sit in a separate area to protect others from getting sick.