H1N1 & Seasonal Influenza

Seasonal Influenza

Seasonal influenza, more commonly known as the flu, refers to illnesses caused by a number of different influenza viruses. The flu can often be mistaken for the common cold because of similar symptoms, but the flu tends to be more severe. In McKinney, flu season usually occurs in December, January and February.

Flu Symptoms

  • Fever, or feelings of fever and chills
  • Coughing and/or sore throat
  • Runny or stuffy nose
  • Headaches and/or body aches
  • Fatigue
  • Vomiting or diarrhea
It is important to remember that individuals will experience these symptoms differently. It is possible to have the flu while experiencing one, some or all symptoms.

Flu Varieties

There are three types of flu viruses: A, B and C. The A and B viruses cause epidemic outbreaks every year in the United States, while type C infections cause mild respiratory illnesses that are not considered to cause epidemics.

A global flu pandemic occurs when a new influenza A virus emerges that has little to no immunity in the human population. These viruses are able to spread very easily from person-to-person and cause serious illness in humans.

H1N1 (Swine Flu) was an example of a global pandemic, as it met all criteria and caused a worldwide outbreak. The first reported case of H1N1 was detected on April 15, 2009 and by April 26, 2009 a public health emergency was declared. On June 11, 2009, H1N1 was declared a global pandemic. As of August 10, 2010, the World Health Organization (WHO) declared that the world was in a post-pandemic stage. H1N1 is still a present strain of the virus and is expected to circulate as a seasonal virus. Because of this, separate vaccines are no longer needed.