Useful Links and Information CDC Quick Reference Guide
for Public Information on Infection Control
* info regarding H1N1 Flu
National Flu Map
Center for Disease Control
South Dakota Department of Health
SD DOH School Health
~ materials include pdf's of Handwashing, illness exclusion
SD DOH Flu Prevention Materials
Flu Facts
Flu Map
Influenza, or the flu, is a respiratory infection caused by a variety of flu viruses. The U.S. Centers for Disease Control and Prevention (CDC) estimates that 35 to 50 million Americans come down with the flu during each flu season, which typically lasts from November to March. Children are two to three times more likely than adults to get sick with the flu, and children frequently spread the virus to others. Although most people recover from the illness, CDC estimates that in the United States more than 100,000 people are hospitalized and about 36,000 people die from the flu and its complications every year.
When and Where Do People Usually Get the Flu?
Flu outbreaks usually begin suddenly and occur mainly in the late fall and winter. The disease spreads through communities creating an epidemic. During the epidemic, the number of cases peaks in about three weeks and subsides after another three or four weeks. Half of the population of a community may be affected. Because schools are an excellent place for flu viruses to attack and spread, families with school-age children have more infections than other families, with an average of one-third of the family members infected each year.
How is the Flu Transmitted?
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 can 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 the greatest risk of getting infected in highly populated areas, such as in crowded living conditions and in schools.
What are Symptoms of the Flu?
Influenza, also known as the flu, is a contagious disease that is caused by the influenza virus. It attacks the respiratory tract in humans (nose, throat, and lungs). The flu is different from a cold. Influenza usually comes on suddenly and may include these symptoms:
These symptoms are usually referred to as "flu-like symptoms."
What about "Stomach Flu"?
Many people use the term "stomach flu" to describe illnesses with nausea, vomiting, or diarrhea. These symptoms can be caused by many different viruses, bacteria, or even parasites. While vomiting, diarrhea, and being nauseous or "sick to your stomach" can sometimes be related to the flu #-- particularly in children #-- these problems are rarely the main symptoms of influenza. The flu is a respiratory disease and not a stomach or intestinal disease.
When is the Flu Contagious?
A person can spread the flu starting one day before he or she feels sick. Adults can continue to pass the flu virus to others for another three to seven days after symptoms start. Children can pass the virus for longer than seven days. Symptoms start one to four days after the virus enters the body. Some persons can be infected with the flu virus but have no symptoms. During this time, those persons can still spread the virus to others.
What Can I Do to Prevent the Flu?
The single best way to prevent the flu is to get vaccinated each fall -- either with a flu shot or using the flu nasal spray vaccine. The nasal spray is approved for use only among healthy people between the ages of 5 and 49 years. The flu shot is approved for use among people over 6 months of age, including healthy people and those with chronic medical conditions. Be aware that the benefits of the vaccine won't take effect immediately.
Three of the antiviral drugs (amantadine, rimantadine, and oseltamivir) have also been approved for prevention of the flu. These drugs are not, however, a substitute for influenza vaccination. All of these drugs are prescription drugs, and a doctor should be consulted before the drugs are used for preventing the flu.
Aside from the vaccine or anti-viral drugs, there are other ways to protect against flu.
What if I Get the Flu?
If you develop flu-like symptoms, but you do not have an underlying medical condition:
Most healthy people recover from the flu without complications. However, there are some "emergency warning signs" that require urgent medical attention.
In children, some emergency warning signs that need urgent medical attention include:
In adults, some emergency warning signs that need urgent medical attention include:
Seek medical care immediately, either by calling your doctor or going to an emergency room, if you or someone you know is experiencing any of the signs described above or other unusually severe symptoms. When you arrive, tell the receptionist or nurse about your symptoms. You may be asked to wear a mask and/or sit in a separate area to protect others from getting sick.
Are There Different Types of Flu Viruses?
The first flu virus was identified in the 1930's. Since then, scientists have classified flu viruses into types A, B, and C.
Type A is the most common and usually causes the most serious epidemics. Type B outbreaks also can cause epidemics, but the disease it produces generally is milder than that caused by type A. Type C viruses, on the other hand, never have been connected with a large epidemic.
What are Possible Complications from the Flu?
You can have flu complications if you get a bacterial infection, which causes pneumonia in your weakened lungs. Pneumonia also can be caused by the flu virus itself.
Symptoms of complications will usually appear after you start feeling better. After a brief period of improvement, you may suddenly get:
Pneumonia can be a very serious and sometimes life-threatening condition. If you have any of these symptoms, you should contact your doctor immediately so that you can get the appropriate treatment.
Are There Other Flu Complications that Only Affect Children?
Reye's syndrome, a condition that affects the nerves, sometimes develops in children and adolescents who are recovering from the flu. Reye's syndrome begins with nausea and vomiting, but the progressive mental changes (such as confusion or delirium) cause the greatest concern.
The syndrome often begins in young people after they take aspirin to get rid of fever or pain. Although very few children develop Reye's syndrome, you should consult a doctor before giving aspirin or products that contain aspirin to children. Acetaminophen does not seem to be associated with Reye's syndrome.
Other complications of the flu that affect children are:
Newborn babies recently out of intensive care units are particularly vulnerable to suffering from flu complications.
Sources: Centers for Disease Control and Prevention (CDC); National Institute of Allergy and Infectious Diseases
Cold Facts
The Problem
In the course of a year, individuals in the United States suffer 1 billion colds, according to some estimates. Colds are most prevalent among children, and seem to be related to youngsters' relative lack of resistance to infection and to contacts with other children in day-care centers and schools. Children have about six to ten colds a year. In families with children in school, the number of colds per child can be as high as 12 a year. Adults average about two to four colds a year, although the range varies widely. Women, especially those aged 20 to 30 years, have more colds than men, possibly because of their closer contact with children. On average, individuals older than 60 have fewer than one cold a year.
Cold Season
In the United States, most colds occur during the fall and winter. Beginning in late August or early September, the incidence of colds increases slowly for a few weeks and remains high until March or April, when it declines. The seasonal variation may relate to the opening of schools and to cold weather, which prompt people to spend more time indoors and increase the chances that viruses will spread from person to person.
Seasonal changes in relative humidity also may affect the prevalence of colds. The most common cold-causing viruses survive better when humidity is low -- the colder months of the year. Cold weather also may make the nasal passages' lining drier and more vulnerable to viral infection.
How Colds are Spread
Depending on the virus type, any or all of the following routes of transmission may be common:
Much of the research on the transmission of the common cold has been done with rhinoviruses, which are shed in the highest concentration in nasal secretions. Studies suggest a person is most likely to transmit rhinoviruses in the second to fourth day of infection, when the amount of virus in nasal secretions is highest. Researchers also have shown that using aspirin to treat colds increases the amount of virus shed in nasal secretions, possibly making the cold sufferer more of a hazard to others.
Prevention
Handwashing is the simplest and most effective way to keep from getting rhinovirus colds. Not touching the nose or eyes is another. Individuals with colds should always sneeze or cough into a facial tissue, and promptly throw it away. If possible, one should avoid close, prolonged exposure to persons who have colds.
Because rhinoviruses can survive up to three hours outside the nasal passages on inanimate objects and skin, cleaning environmental surfaces with a virus-killing disinfectant might help prevent spread of infection.
A cold vaccine? The development of a vaccine that could prevent the common cold has reached an impasse because of the discovery of many different cold viruses. Each virus carries its own specific antigens, substances that induce the formation of specific protective proteins (antibodies) produced by the body. Until ways are found to combine many viral antigens in one vaccine, or take advantage of the antigenic cross-relationships that exist, prospects for a vaccine are dim. Evidence that changes occur in common-cold virus antigens further complicate development of a vaccine. Such changes occur in some influenza virus antigens and make it necessary to alter the influenza vaccine each year.
Source: National Institute of Allergy and Infectious Diseases