Flu
(Influenza)
See also:
Definition
The flu is an infection. It affects the respiratory system. The flu is caused by a virus.
The Upper Respiratory Tract
Causes
The flu is caused by the influenza virus. Each winter, the virus spreads around the world. The strains are usually different from one year to the next.
The two main kinds of influenza viruses, Type A and Type B.
Someone infected with the virus may sneeze or cough. This releases droplets in the air. If you breathe in infected droplets you can become infected. You can also become infected through touch. If you touch a contaminated surface, you may transfer the virus from your hand to your mouth or nose.
Risk Factors
Factors that increase your chance of the flu include:
-
Living or working in crowded group conditions, such as:
- Nursing home
- School
- Military forces
- Daycare center
All the remaining factors increase the risk of developing complications from flu:
- Age: newborn babies and the elderly
- Women in the third trimester of pregnancy
- Diabetes
-
Weakened immune systems, such as in:
- Cancer patients
- AIDS patients
- People taking immunosuppressive drugs
- People who have had their spleen removed
- Chronic lung, heart, kidney, or blood conditions
Symptoms
Symptoms usually start abruptly. They may include:
- Fever and chills
- Severe muscle aches
- Severe fatigue
- Headache
- Decreased appetite, other gastrointestinal symptoms like nausea and vomiting
- Runny nose, nasal congestion
- Sneezing
- Watery eyes, conjunctivitis
- Sore throat
- Cough
- Swollen lymph nodes in the neck
You may start to feel better in 7-10 days, but you may still have a cough and feel tired.
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done. Diagnosis of the flu is usually based on symptoms. It also hits communities. the doctor may anticipate more infections.
Samples of nasal secretions or a throat swab can be sent to a lab. This will confirm the diagnosis. Blood tests can be performed, but they take longer and are more expensive.
Treatment
Treatment may include:
Antiviral Medicines
Antiviral medicines include:
- Zanamivir
(Relenza)
- This medicine may worsen asthma or chronic obstructive pulmonary disease (COPD).
- Oseltamivir (Tamiflu)
Oseltamivir (and perhaps zanamivir) may increase the risk of self-injury and confusion shortly after taking, especially in children. Children should be closely monitored for signs of unusual behavior.
These medications do not cure the flu. They may help relieve symptoms and decrease the duration of the illness. They must be taken within 48 hours of the first symptoms.
Bed Rest
It is important to get plenty of rest when your body is fighting the flu.
Fluids
Drink a lot of liquids. This can include water, juice, and non-caffeinated tea.
Over-the-Counter Pain Relievers
These medications are used to control fever and treat aches and pains. Adults can use:
- Acetaminophen
- Ibuprofen
- Aspirin
- Note: Aspirin is not recommended for children or teens with a current or recent viral infection. Check with your doctor before giving a child or teen aspirin.
Decongestants
Decongestants are available as pills or nasal sprays. If you use a nasal spray, don't use it longer than 3-5 days. You may experience an increase in congestion when you stop using the spray. This is called rebound.
Saline Nasal Sprays
A study found that nasal wash may reduce symptoms, medication use, and school absence. * 4
Cough Medicines
These include:
-
Over-the-counter (OTC) cough and cold medicines, including decongestants, expectorants, antihistamines, cough suppressants
- OTC cough and cold products should not be used to treat infants or children less than two years old. Rare but serious side effects have been reported. They include death, convulsions, rapid heart rates, and decreased levels of consciousness. The safety of these products in Serious side effects have also been reported in children aged 2-11 years. Research is still going on for the safety of OTC flu products for this age group. * 3
- Prescription cough medicines
- Cough drops
If you are diagnosed with the flu, follow your doctor's instructions .
Prevention
Good preventive measures include:
- Avoid close contact with people who have respiratory infections.
- Wash your hands often, especially when you come in contact with someone who is sick. Rubbing alcohol-based cleaners on your hands is also helpful.
- Do not share drinks or personal items.
- Do not bite your nails or put your hands near your eyes, mouth, or nose.
-
Consider the
flu vaccine
. You will need one each year since the exact virus changes.
-
Indications for a yearly flu vaccine, which should be discussed with your doctor:
- Persons older than 50 years of age
- Residents and employees of nursing homes and long-term care facilities
- People with chronic heart and lung conditions
- People with chronic metabolic disease, kidney problems, hemoglobin abnormalities, or immune system problems
- Children and teenagers routinely taking aspirin
- Pregnant women
- Healthcare providers
- Household members of high-risk individuals
- Children age six months to five years
- Anyone wishing to reduce their risk of getting the flu should consider the vaccine.
-
Indications for a yearly flu vaccine, which should be discussed with your doctor:
For the elderly in the community, vaccine can lead to fewer hospitalizations and deaths. * 2
Two forms of flu vaccine are available. One is an injectable form and the other is a nasal spray (FluMist). Studies found that the nasal spray led to fewer cases of influenza in a single flu season. Talk to your doctor about which vaccine is the most appropriate for you or your child. * 1
RESOURCES:
American Lung Association
http://www.lungusa.org/
Centers for Disease Control and Prevention
http://www.cdc.gov/flu
CANADIAN RESOURCES:
Health Canada
http://www.hc-sc.gc.ca/
Public Health Agency of Canada
http://www.phac-aspc.gc.ca/chn-rcs/index-eng.php/
References:
American Lung Association website. Available at: http://www.lungusa.org .
CDC MMWR 2006;55(RR10):1-42.
Derlet R, Lawrence R. Influenza. Emedicine website. Available at: http://www.emedecine.com/med/topic1170.htm .
DynaMed Editorial Team. Influenza. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. Updated May 1, 2009. Accessed May 1, 2009.
Griffith's 5-Minute Clinical Consult . Lippincott Williams & Wilkins; 1999.
Influenza vaccines. WHO position paper. Wkly Epidemiol Rec . 2002;77:229-240. World Health Organization website. Available at: http://www.who.int/docstore/wer/pdf/2002/wer7728.pdf . Accessed August 30, 2005.
Leblebicioglu H, Brook I. Influenza. Emedicine website. Available at: http://www.emedecine.com .
MMWR Weekly: Recommended immunization schedules for 0-18 years-United States, 2008. Center for Disease Control website. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5701a8.htm . Updated January 11, 2008. Accessed January 24, 2008.
National Institute of Allergy and Infectious Disease website. Available at: http://www3.niaid.nih.gov/ .
Principles and Practice of Infectious Diseases. 5th ed. Churchill Livingstone, Inc; 2000.
* 1 3/2/2007 DynaMed Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Belshe RB, Edwards KM, Vesikari T, et al. Live attenuated versus inactivated influenza vaccine in infants and young children. N Engl J Med. 2007;356:685-696.
* 2 10/15/2007 DynaMed Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Nichol KL, Nordin JD, Nelson DB, Mullooly JP, Hak E. Effectiveness of influenza vaccine in the community-dwelling elderly. N Engl J Med. 2007;357:1373-1381.
* 3 1/30/2008 DynaMed Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Public health advisory: Nonprescription cough and cold medicine use in children—FDA recommends that over-the-counter (OTC) cough and cold products not be used for infants and children under 2 years of age. US Food and Drug Administration website. Available at: http://www.fda.gov/cder/drug/advisory/cough_cold_2008.htm . Accessed January 30, 3008.
* 4 2/28/2008 DynaMed Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Slapak I, Skoupá J, Strnad P, Horník P. Efficacy of isotonic nasal wash (seawater) in the treatment and prevention of rhinitis in children. Arch Otolaryngol Head Neck Surg. 2008;134:67-74.
* 5 3/12/2008 DynaMed Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : 2008 safety alerts for drugs, biologics, medical devices, and dietary supplements: tamiflu (oseltamivir phosphate). US Food and Drug Administration website. Available at: http://www.fda.gov/medwatch/safety/2008/safety08.htm#Tamiflu . Accessed March 12, 2008.
Last reviewed January 2009 by Rosalyn Carson-DeWitt, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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