Tis the Season...For Flu
What is influenza (flu)?
Influenza (flu) is a viral infection. People often use the term “flu” to describe any kind of mild illness, such as a cold or a stomach virus that has symptoms like the flu. But the real flu is different. Flu symptoms are usually worse than a cold and last longer. The flu usually does not cause vomiting or diarrhea in adults.
Most flu outbreaks happen in late fall and winter. Because symptoms may not start for a couple of days, you may pass the flu to someone before you know you have it.
What causes the flu?
The flu is caused by the influenza virus. Common classes of the influenza virus are type A and type B, each of which includes several subtypes or strains. Type A is usually responsible for the annual outbreaks that typically occur in the late fall and early winter.
The influenza virus changes often, so having flu caused by one strain does not give you full immunity to other strains.
· Widespread outbreaks of the flu usually follow significant changes (called antigenic shifts) in the virus and occur about every 10 years. People who get the flu tend to become much sicker when a shift in the flu virus occurs.
· Minor changes in the virus (called antigenic drifts) occur nearly every year.
The virus is spread from person to person through:
- Direct contact, such as shaking hands
- Small droplets that form when a person sneezes or coughs
- Contact with objects such as handkerchiefs that have been in contact with fluids from an infected person’s nose or throat.
When are you contagious?
If you are infected with the flu, you are most likely to pass it someone else from 1 day before symptoms start and up to 7 days after symptoms develop. Children may be infections for longer than 7 days after symptoms start.
Symptoms usually develop 1 to 4 days after you are infected. Because symptoms may not develop for a couple of days, you may pass the flu to someone before you know you have it.
What are the symptoms?
The symptoms of influenza (flu) appear suddenly and often include:
- Fever of 100.4°F (38°C) to 104°F (40°C) when symptoms first develop. Fever is usually continuous, but it may come and go. Fever may be lower in older adults than in children and younger adults. When fever is high, other symptoms usually are more severe.
- Body aches and muscle pain (often severe), commonly in the back, arms, or legs
- Pain when you move your eyes
- Fatigue, a general feeling of sickness (malaise), and loss of appetite.
- A dry cough, runny nose, and dry or sore throat. You may not notice these during the first few days of the illness when other symptoms are more severe. As your fever goes away, these symptoms may become more evident.
Some people get infected with the flu virus but do not have any symptoms.
Influenza usually does not cause symptoms in the stomach or intestines, such as vomiting and diarrhea.
Other conditions have symptoms similar to the flu, such as the common cold, bacterial infections, and infectious mononucleosis.
Influenza (flu) usually comes on suddenly. In many cases people can pinpoint the hour when symptoms started. Symptoms develop 1 to 4 days after you are infected, and they include:
- Fever, which lasts for about 3 days. Fever is usually slightly lower on the 2nd and 3rd days but may last up to 8 days.
- Cough, runny nose, and sore throat, which become more noticeable as fever and other symptoms decrease. These symptoms usually last 3 to 4 days after the fever goes down. A dry, hacking cough may linger for up to 10 days after other symptoms are gone.
Complete recovery may take 1 to 2 weeks or longer. Fatigue and weakness can last for several weeks.
Complications of influenza may develop in anyone, but they are much more likely in older adults and people who have other health problems, especially heart and lung diseases.
What increases your risk?
Anyone exposed to an influenza virus can become infected. These viruses are contagious and spread easily among people in groups, such as in nursing homes, hospitals, shelters, schools, and day cares. Working, visiting, or living in any of these areas increases your risk of getting the flu.
The risk of having severe symptoms and complications is higher for:
- Children younger than 2 years of age
- Adults age 65 or older
- Pregnant women
- People who have chronic obstructive pulmonary disease (COPD), other lung diseases, or heart failure
- People who have a medical condition (such as acquired immunodeficiency syndrome [AIDS]) or who are using a medicine that impairs the immune system.
When to call a doctor
Call emergency services if you are having trouble breathing, feel short of breath, have a severe headache or stiff neck and are confused or having trouble staying awake.
Call your doctor if:
- You have an extremely high fever
- Your fever lasts longer than three days
- Your child is 3 months of age or younger and has a fever of 100.4°F (38°C) or higher
- You are finding it harder and harder to breathe
- Wheezing develops
- New pain develops or pain localizes to one area, such as an ear, the throat, the chest, or the sinuses
- Symptoms do not go away, even with home treatment
- Symptoms become more severe or frequent
In most healthy people, the flu will go away in 5 to 7 days, although fatigue can l
ast much longer. Although you may feel very sick, home treatment is usually all that is needed. If it is flu season, you may just want to treat your symptoms at home. Watch closely for symptoms of a bacterial infection, such as nasal drainage that changes from clear to colored after 5 to 7 days and symptoms that return or get worse.
Early treatment with an antiviral medicine may reduce the severity of influenza and may prevent serious flu-related complications. It is best to start these medicines within 48 hours of the start of symptoms. Babies, older adults and people who have chronic health problems are more likely to have complications from the flu, and they may need to see a doctor for care beyond home treatment. But not all antiviral medicines work against all strains of the flu. Talk to your doctor if you think you may need an antiviral medicine.
Call your doctor if you think your symptoms are caused by something other than the flu.
Doctors can diagnose influenza using your symptoms alone if many cases of a similar illness have occurred in the community and if the local health department has confirmed a flu outbreak.
Tests to confirm you have the flu and to find out the type of virus may be important if:
- The results may affect treatment decisions. During a confirmed flu outbreak, though, testing may not be needed even if treatment with an antiviral medicine is being considered.
- In addition to flu-like symptoms, you have any unusual symptoms that suggest another condition
- Health authorities have not identified any other cases of flu in your area.
Testing may involve blood tests (rarely used) or a culture to identify the virus. Some cultures take 24 to 48 hours for results, so they will not help your doctor decide whether to prescribe an antiviral medicine. A rapid flu test is now available that gives results in 30 minutes. Although this test is not 100% accurate, it can be useful when deciding whether to use an antiviral medicine.
In most healthy people, influenza will go away in 5 to 7 days. The worst symptoms usually last 3 to 4 days. Home treatment to ease symptoms and prevent complications is usually all that is needed.
But some people need treatment in the hospital. They may have severe symptoms or get pneumonia. Or the flu infection may make an existing health problem worse.
Antiviral medicines may help:
- Reduce the severity and duration of symptoms caused by infection with influenza A or B virus
- Shorten the length of the illness
- Control outbreaks of the flu in nursing homes
- Reduce the spread of the virus to people at high risk for severe complications of the flu
- Reduce complications from the flu
People at high risk of complications are encouraged to contact a doctor within 48 hours of their first symptoms to find out whether they need medicine to shorten the illness. They also should call a doctor to receive medicine if they have been exposed to the flu.
If you have influenza, you can expect the illness to go away on its own in about 7 to 10 days. In the meantime, you can take steps to feel better:
- Get extra rest. Bed rest can help you feel better. It will also help you avoid spreading the virus to others.
- Drink plenty of fluids to replace those lost from fever. Fluids also ease a scratchy throat and keep nasal mucus thin. Water, soup, fruit juice, and hot tea with lemon are all good choices.
- If fever is uncomfortable, sponge your body with lukewarm water to reduce fever. Do not use cold water or ice. Lowering the fever will not make your symptoms go away faster, but it may make you more comfortable.
- To help clear a stuffy nose, breathe moist air from a hot shower or from a sink filled with hot water.
- If the skin around your nose and lips becomes sore from repeated rubbing with tissues, apply a bit of petroleum jelly to the area. Using disposable tissues that contain lotion also may help.
- Elevate your head at night with an extra pillow if coughing keeps you awake.
- Avoid smoking and breathing secondhand smoke. This is good advice anytime, but it is especially important when you have a respiratory infection like a cold or the flu.
- Try an over-the-counter medicine to help relieve your symptoms. Be safe with medicines. Read and follow all instructions on the label. Cough and cold medicines may not be safe for young children or for people who have certain health problems.
o To relieve body aches and headache or to lower fever, try acetaminophen or ibuprofen. If you give medicine to your baby, follow your doctor’s advice about what amount to give.
o For a stuffy nose, try a nasal or oral decongestant (such as Afrin or Sudafed PE) or a steroid nasal spray (such as Nasacort.) Do not use a nasal decongestant longer than the label says. Overuse can cause a “rebound effect.” It makes your mucous membranes swell up more than before you used the spray.
o If you have a dry, hacking cough, you can try a cough suppressant to help stop the cough reflex.
o To soothe a sore throat, use throat lozenges or plain, hard candy.
o Avoid antihistamines. They do not treat flu symptoms and may make nasal drainage thicker.
Call your doctor if:
- Your symptoms improve but then seem to get worse again
- You have symptoms of a bacterial infection, such as a new or worse cough that produces yellow, green, rust-colored or bloody mucus; persistent fever, ear pain, sore throat, sinus pain, or productive cough; or nasal drainage that changes from clear to colored after 7 to 10 days.
You can help prevent influenza by getting immunized with an influenza vaccine each year as soon as it’s available.
Yearly immunization with the inactivated influenza vaccine (flu shot) or the nasal spray flu vaccine prevents flu infection and its complications in most people.
Most healthy people ages 2 through 49 years can choose to get the nasal spray form of the vaccine (such as FluMist) instead of the flu shot. The nasal spray vaccine contains components of live viruses, so it should not be given to people who have certain long-term (chronic) health conditions, such as heart or lung problems. Close contacts of these people in high-risk categories can be given either type of vaccine, with one rare exception. Immunization with the inactivated virus (flu shot) is preferred over the nasal spray vaccine for close contacts of people with severely impaired immune systems during times when a protected environment is needed. This avoids the risk of transmitting an active flu virus from the nasal spray vaccine. If the nasal spray vaccine is used, contact with anyone in this high-risk group should be avoided for 7 days. For close contacts of people in all other high-risk categories, vaccination with either the flu shot or the nasal spray is considered safe.
You should not get the nasal spray if you:
- Have heart disease
- Have lung disease, including asthma
- Have diabetes or kidney disease
- Have a disease or take a medicine that causes problems with your immune system
- Have a condition (such as a seizure disorder or cerebral palsy) that can cause breathing or swallowing problems.
- Are pregnant
- Are younger than age 20 and you take aspirin or products with aspirin in them.
Even if a flu vaccine does not prevent the flu, it can reduce the severity of flu symptoms and decrease the risk of complications. Studies have found that the flu shot results in fewer days missed from work and fewer visits to a doctor for respiratory infections, and it reduces the number of people who develop complications from the flu, such as pneumonia. And the flu vaccine can help protect the babies of women who got the vaccine while they were pregnant.
In spite of these results, many people choose not to get a flu vaccine. Some do not get the vaccine because of myths they believe about the flu or the vaccines. These include beliefs that the flu is a minor illness or that the vaccine causes the flu. The shot may cause side effects, such as soreness or fever, but they are usually minor and do not last long. And a type of flu shot (Fluzone Intradermal) is available that uses a much smaller needle than a regular flu shot. It is injected into the skin instead of into a muscle. This usually causes less discomfort at the time of the shot. People 18 to 64 years old can get this shot. Most, but not all, types of flu vaccine contain a small amount of egg.
Although antiviral medicines sometimes prevent the flu, they do not work in the same way as a yearly immunization and should not replace a flu shot or dose of the nasal spray vaccine.
The person who gives the vaccine may tell your child or you not to get it if your child or you:
- Have a severe allergy to eggs or any part of the vaccine. Have had a serious reaction to a previous dose of flu vaccine.
- Have had Guillain-Barre syndrome
- Are sick. If you are ill and have a fever, wait until you’re better before you get a flu vaccine.
Because the nasal spray vaccine is more expensive than a flu shot, it may not be covered by your health insurance plan. Check with your insurance company.
Almost every community has a program that offers flu vaccines at low cost during the flu season. You also can get a flu vaccine during a routine visit to a doctor or pharmacy. Many health clinics have set hours at the start of the flu season for people to get flu vaccines without needing to make an appointment.
Other ways to reduce your risk for the flu or flu complications
Increase your chance of staying healthy by:
- Washing your hands often, especially during winter months when the flu is most common.
- Keeping your hands away from your nose, eyes, and mouth. Viruses are most likely to enter your body through these areas.
- Eating a healthy and balanced diet
- Getting regular exercise
- Not smoking. Smoking irritates the lining of your nose, sinuses, and lungs, which may make you susceptible to complications of the flu.
Using antiviral medicines to prevent the flu
Two antiviral medicines (oseltamivir and zanamivir) can help prevent the flu caused by influenza A and B viruses. These medicines may also reduce the length of the illness if they are given as soon as possible after the first symptoms. During a flu outbreak these medicines may be given at the same time as a flu vaccine and for 2 weeks after while your body produces antibodies to protect you from the virus. The influenza medicines are usually given to people who are very sick with the flu or those who are likely to have complications from the flu. But they may also be used for a person who has been sick with the flu for less than 48 hours. These medicines are taken by mouth (pill) or inhaled into the lungs (inhaler).
The antiviral medicine amantadine and rimantadine have been used to prevent flu caused by influenza A. But for the past few years the U.S. Centers of Disease Control and Prevention (CDC) has advised doctors not to use these medicines to treat or prevent the flu. These medicines have not worked against most types of the flu virus. Amantadine and rimantadine do not protect against influenza B. Be sure to talk with your doctor about the medicine that is best for you.