Influenza (“the flu”) is a common respiratory illness that is highly contagious and is caused by various types of influenza viruses (the most common being Type A and Type B). It infects the nose, throat and lungs, with symptoms that include fever, cough, sore throat, a runny nose and fatigue.

Flu shot warning

Symptoms & Complications

Symptoms for the flu illness are often just a mild and unpleasant hindrance that lasts a few days, but in some cases, the complications can become severe. Young children (those under 5), older adults (65 and older), pregnant women and those with medical conditions (especially illnesses involving the lungs, kidneys, liver, heart and blood) are at higher risk for developing the severe complications that can lead to pneumonia, ear and sinus infections and even death.

Symptoms typically last 3 to 5 days, but adults can transmit the illness to others from 1 day before the symptoms develop to up to 7 days after becoming sick. Flu “season” in St. Charles County ranges from September through May, but the illness can occur at any time during the year. For more information on preventing the spread of the flu, please visit the Centers for Disease Control and Prevention (CDC).

Preventing the Flu

According to the CDC, the best means for preventing the flu is for all individuals ages six months and older to get a flu vaccination annually. The vaccination is designed to protect against all strains anticipated for the coming season.

While getting the flu vaccine is the most important step in protecting against the illness, there are many additional things you can do to prevent the spread. Washing your hands regularly, especially after coughing or sneezing and before eating, will help to kill the virus. In addition, if you cough or sneeze, remember to cover your nose and mouth and to throw away soiled tissues. Another precaution is to avoid sharing drink glasses or utensils. Lastly, if you do become sick with the flu, medical professionals advise staying home until fully recovered.

Seasonal Flu vs. Common Cold

Symptoms for the flu and the cold are similar, although they are typically milder when involving a cold. Since the symptoms are so similar, it is difficult to distinguish one from the other without undergoing a special test during the first days of the illness. Caused by different types of viruses, the biggest difference between the two is that colds generally do not develop into the more serious complications.


A pandemic illness is one that spreads throughout the community and is one where the population has little or no immunity. This is a serious incident as the illness spreads easily to a wide range of people and will seriously impact the community. The risks involved in the rapid spread of illness are that the health care system would be overwhelmed, medical supplies will likely be inadequate and that economies would suffer from the lost output of sick workers. While seasonal flu strikes annually, a pandemic is a rare and significant occurrence.

A flu pandemic can happen when a new subtype of the Type A influenza virus is introduced to the human population. This has recently occurred in the outbreak of:

  • H1N1 virus (“Swine Flu”) - It was first detected in the United States in April 2009, the H1N1 virus is estimated to have caused more than 1 million cases - with schoolchildren, young adults and pregnant women the most affected. The U.S. Public Health emergency declared for the 2009 H1N1 expired in June 2010. Current flu vaccinations are designed to protect against the spread of this illness.
  • H5N1 virus (“Avian Flu”) - Highly contagious and deadly among birds, around 500 human cases of infection have been reported since the virus was detected in 2003 (none in the United States). Since humans have little or no immunity to the H5N1 strain, the World Health Organization monitors the threat of this pandemic.
  • “The Great Pandemic” (1918-1919) - Occurring in three waves throughout the United States and Europe, the 1918-1919 Flu Pandemic killed more than 30 million around the world, including more than 675,000 Americans.