What is in-floo-en-zah??
Influenza, also called the flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses).
In humans, common symptoms of influenza infection are fever, nausea, vomiting, sore throat, muscle pains, severe headache, coughing, and weakness and fatigue. In more serious cases, influenza causes pneumonia, which can be fatal, particularly in young children and the elderly.
Sometimes confused with the common cold, influenza is a much more severe disease and is caused by a different type of virus. Similarly, the unrelated gastroenteritis is sometimes called "stomach flu" or "24-hour flu".
What causes the flu?
Flu is caused by a variety of influenza viruses. Researchers identified the first virus in the 1930s. Since then, they have classified influenza viruses into types A, B, and C. Influenza A and C infect multiple species, while influenza B almost exclusively infects humans.
How can I infected by?
Typically, influenza is transmitted from infected mammals through the air by coughs or sneezes, creating aerosols containing the virus, and from infected birds through their droppings. Influenza can also be transmitted by saliva, nasal secretions, feces and blood. Infections occur through contact with these bodily fluids or with contaminated surfaces.
So, you can get the flu if someone around you who has the flu coughs or sneezes. You can get the flu simply by touching a surface like a telephone or door knob that has been contaminated by a touch from someone who has the flu. The viruses can pass through the air and enter your body through your nose or mouth. If you've touched a contaminated surface, they can pass from your hand to your nose or mouth. You are at greatest risk of getting infected in highly populated areas, such as in crowded living conditions and in schools.
Flu viruses can remain infectious for about one week at human body temperature, over 30 days at 0 °C (32 °F), and indefinitely at very low temperatures (such as lakes in northeast Siberia). They can be inactivated easily by disinfectants and detergents.
How about any symptoms?
If you get infected by the flu virus, you will usually feel symptoms 1 to 4 days later. You can spread the flu to others before your symptoms start and for another 3 to 4 days after your symptoms appear. Common symptoms of the flu such as fever, headaches, and fatigue come from the huge amounts of proinflammatory cytokines and chemokines (such as interferon or tumor necrosis factor) produced from influenza-infected cells. In contrast to the rhinovirus that causes the common cold, influenza does cause tissue damage, so symptoms are not entirely due to the inflammatory response. Symptoms of influenza may include:
- Body aches, especially joints and throat
- Coughing and sneezing
- Extreme coldness and fever
- Irritated watering eyes
- Nasal congestion
- Nausea and vomiting
- Reddened eyes, skin (especially face), mouth, throat and nose
What can I do to feel better?
There's no cure for a cold or the flu. Antibiotics don't work against viruses. All you can do to feel better is treat your symptoms while your body fights off the virus (see the box below). This below are ways to treat your cold/flu symptoms:
- Stay home and get plenty of rest, especially while you have a fever.
- Stop smoking and avoid secondhand smoke, which can make cold symptoms worse.
- Drink plenty of fluids like water, fruit juices and clear soups. Fluids help loosen mucus. Fluids are also important if you have a fever because fever can dry up your body's fluids, which can lead to dehydration.
- Don't drink alcohol.
- Gargle with warm salt water a few times a day to relieve a sore throat. Throat sprays or lozenges may also help relieve the pain. Use saline (salt water) nose drops to help loosen mucus and moisten the tender skin in your nose.
- Taking over-the-counter medicine such as aspirin or acetaminophen (Tylenol, for example) relieve the fever and muscle aches associated with the flu.
- Don’t take aspirin during an influenza infection (especially influenza type B) for children and teenagers with flu symptoms (particularly fever). Because doing so can lead to Reye syndrome, a rare but potentially fatal disease of the liver.Since influenza is caused by a virus, antibiotics have no effect on the infection; unless prescribed for secondary infections such as bacterial pneumonia, they may lead to resistant bacteria. Antiviral medication is sometimes effective, but viruses can develop resistance to the standard antiviral drugs.
What medicine should I took for treatment?
If you do get the flu and want to take medicine to treat it, your health care provider may prescribe an antiviral medicine.
- Tamiflu (oseltamivir) is for treating influenza A and B virus infections in adults and children 1 year and older.
- Relenza (zanamivir) is for treating influenza A and B virus infections in children 7 years and older and adults who have an uncomplicated flu infection and who have had symptoms for no more than 2 days.
What's in over-the-counter flu medicines?
The ingredients listed below are found in many flu medicines. Read labels carefully. If you have questions, talk to your doctor or pharmacist.
- Analgesics relieve aches and pains and reduce fever. Examples: acetaminophen, aspirin, ibuprofen, ketoprofen, naproxen. Warning: Children and teenagers shouldn't be given aspirin.
- Antitussives tell your brain to stop coughing. Don't take an antitussive if you're coughing up mucus. Example: dextromethorphan.
- Expectorants help thin mucus so it can be coughed up more easily. Example: guaifenesin.
- Oral decongestant shrinks the nasal passages and reduce congestion. Examples: ephedrine, pseudoephedrine.