Is it influenza or a common cold? Recognizing differences, preventing infection, and easing the symptoms.

Now that the flu and cold seasons are upon us, it’s time to help you decide whether you may have the flu or a cold and suggest options to help in easing the symptoms. The January article focuses on influenza. A second follow-up one in our next newsletter will be about the common cold and popular myths.

Causes of influenza (flu): The flu, a contagious upper respiratory illness, is caused by one of several flu viruses and can cause mild to severe illness. It usually comes on suddenly and may include symptoms of fever (usually high), headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, muscle aches, and more likely in children, possible stomach symptoms such as nausea, vomiting, and diarrhea. The most familiar aspect of the flu is the way it can "knock you off your feet." The fever typically tends to decline on the second or third day. In our country, the flu season usually ranges from November to late May. Flu viruses are classified as Types A, B, and C; Type A has a number of subtypes. The viruses are frequently named after the geographical locations from which the viruses originate (e.g., Hong Kong, Russian, Asian, etc.). Individuals most vulnerable to serious effects of the flu are older adults, infants, and immune-compromised persons.

Transmitting the flu: The main transmission way is from person to person in respiratory droplets of coughs and sneezes ("droplet spread"). For example, touching contaminated surfaces where people have coughed or sneezed on places such as phones, tables, money and then touching one’s nose or mouth. Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 days after becoming sick. Children may pass the virus for longer than seven days.

The Myth of the "Stomach Flu": People use the term "stomach flu" to describe illnesses with nausea, vomiting, or diarrhea. While "sick to your stomach" can sometimes be related to the flu (particularly in children) it is rarely the main symptom of influenza. Influenza is a respiratory disease and not a stomach or intestinal disease.

Preventing influenza: single best way to prevent seasonal flu is to get vaccinated each year. In a nutshell, consider the following suggestions: avoid close contact with sick persons; stay home when sick; cover mouth and nose when coughing or sneezing; wash hands often; and avoid touching your nose, eyes, or mouth; and of course, practice good health habits (physical exercise, stress management, nutritional diets). There is conflicting data about use of antiviral drugs (e.g., rimantadine, amantadine) to treat and prevent influenza. CDC’s recommendation is that people should not take these medicines to treat flu because Influenza A virus is resistant to them. For use of drugs and their side effects, check this site: http://www3.niaid.nih.gov/healthscience/healthtopics/Flu/understandingFlu/Treatment.htm

Sometimes, an unpredicted new strain may appear after the vaccine has been made and distributed. If vaccinated, you still may get infected. If so, the disease usually is milder because the vaccine will still give some protection. To get the latest information about “flu activity” (that is, current incidence of flu in U.S.) go to http://www.cdc.gov/flu/