Influenza, or flu, is a respiratory illness that is caused by a virus.
Flu is highly contagious and is usually spread by the coughs and sneezes
of a person who is infected. You can also catch flu from an infected
person if you touch them (e.g. shaking hands). Adults are contagious one
day before getting symptoms and up to 7 days after becoming ill. This
means that you can spread the influenza virus before you even know you
are infected. A flu epidemic, when a large number of people in one
country are infected with flu, can last several weeks.
What are the symptoms of flu?
It is common to confuse flu with a bad cold. Flu and cold symptoms may
include a runny/blocked nose, sore throat, and cough. Here are some
symptoms which a person with flu will have. These are not common heavy
- high temperature
- cold sweats, shivers
- aching joints, aching limbs
- fatigue, feeling utterly exhausted
- gastro-intestinal symptoms, such as nausea, vomiting, and diarrhea, are much more common among children than adults
These symptoms may linger for about a week. The feeling of tiredness and gloom can continue for several weeks.
How serious is flu?
In the majority of cases flu is not serious - it is just unpleasant. For
some people, however, there can be severe complications. This is more
likely if you are elderly or have some other longstanding illness that
can undermine your immune system. Your risk of experiencing severe flu
complications is higher if:
- you are over 65
- you are a baby or a very young child
- you are pregnant
- you have some kind of heart or cardiovascular disease
- you have a chest problem, such as asthma or bronchitis
- you have a kidney disease
- you suffer from diabetes
- you are taking steroids
- you are undergoing treatment for cancer
- you have any longstanding disease that can significantly lower your immune system
Some of the complications caused by influenza may include bacterial
pneumonia, dehydration, and worsening of chronic medical conditions,
such as congestive heart failure, asthma, or diabetes. Children may get
sinus problems and ear infections.
What should I do if I have flu?
As flu is caused by a virus, antibiotics won't do any good, unless the
flu has led to another illness. Some of the symptoms, such as headache
and body pains may be alleviated if you take a painkiller. Some
painkillers, such as aspirin, should not be given to children under 12 (Department of Health, United Kingdom)
. If you have flu you should:
If I have flu should I tell my doctor?
- stay at home
- try to avoid contact with other people
- keep warm and rest
- make sure you consume plenty of liquids
- don't consume alcohol
- if you are a smoker stop smoking or cut your consumption down as much as you can
- try to get some food down (eat what you can)
- if you live alone, tell a relative, friend or neighbor that you have
flu. Make sure someone can check in on you and do your shopping
According The Department of Health, UK, you should only contact your
doctor if you are frail or elderly, your temperature remains high after
four to five days, your symptoms worsen, you think you are seriously
ill, you become short of breath, and/or you develop chest pain. A phone
call to your doctor if you are worried may be a better solution than
making an appointment.
Flu in the USA
In the United States approximately 5% to 20% of the population gets flu,
according to the Centers of Disease Control and Prevention (CDC). Over
200,000 people are hospitalized from flu complications each year, and
about 36,000 people are estimated to die as a result of flu.
Flu in the world
According to the World Health Organization (WHO), in annual influenza
epidemics 5% to 15% of the world's population become ill with upper
respiratory tract infections. Hospitalization and deaths mainly occur in
high-risk groups. It is estimated that between one quarter to one half
of a million people die each year as a result of flu. In industrialized
countries the majority of deaths as a result of flu occur among people
over the age of 65 years.
How to prevent flu
Health experts and government agencies throughout the world say that the
single best way to protect yourself from catching flu is to get
vaccination every year. There are two types of vaccinations, the flu shot
and the nasal-spray flu vaccine
The flu shot is administered with a needle, usually in the arm - it is
approved for people older than six months, including healthy people and
those with chronic medical conditions. The nasal-spray flu vaccine is a
vaccine made with live, weakened flu viruses that do not make you ill.
A flu vaccine will contain three influenza viruses - One A (H3N2) virus,
one A (H1N2) virus, and one B virus. As viruses adapt and change, so do
those contained within the vaccines - what is included in them is based
on international surveillance and scientists' calculations about which
virus types and strains will circulate in a given year. You are
protected about two weeks after receiving the vaccination.
Annual flu vaccinations should start in September or as soon as the
vaccine is on hand and continue throughout the flu season, into January,
and beyond. This is because the timing and duration of influenza
seasons are never the same. Flu outbreaks usually peak at around
January, but they can happen as early as October.
The flu vaccine is not suitable for some people
You should check with your doctor before deciding to have the flu vaccine if:
There are three types of flu viruses
- you have a severe allergy to chicken eggs
- you have had a severe reaction to a flu vaccination
- you developed Guillain-Barré Syndrome within six weeks of receiving a flu vaccine
- you are less than six months old
- you have a fever with a moderate-to-severe illness. You should wait till you recover before being vaccinated
Three types of flu viruses exist - infuenza A, influenza B and influenza C
Types A and B viruses cause seasonal epidemics which hit the USA and
Europe virtually every winter. The type C influenza virus causes mild
respiratory illness and is not responsible for epidemics.
Two proteins on the surface of influenza A viruses divide it into
subtypes - the hemagglutinin (H) and the neuraminidase (N). 16 different
hemagglutinin subtypes and 9 different neuraminidase subtypes are known
to exist. The current subtypes of influenza A viruses found in people
are A (H1N1) and A (H3N2).
There are no B virus subtypes, but there are different influenza B virus strains.