Influenza- Background & Basics

History of disease- The Influenza Pandemic occurred in several larger waves that began in 1918. The first Influenza Pandemic of 1918-1919 was also coined "The Spanish Flu" because it was thought to have spread from Spanish migrant workers who would travel from France to Spain in unsanitary working conditions (although nearly a century later, epidemiologists confirm that the influenza virus did not in fact originate in Spain). The influenza then rapidly spread through close contact in trenches, crowded barracks, trading routes and shipping lines.  The pandemic killed anywhere between 20-50 million people world wide (http://cid.oxfordjournals.org/content/47/5/668.full) Furthermore, the influenza pandemic infected 28% of all Americans, and killed nearly 675,000 people (https://virus.stanford.edu/uda/)

The next large outbreak was from 1957-1958 that impacted the United States in a series of smaller outbreaks. According to Flu.gov, infection rates were highest amongst school children, young adults, and pregnant women (http://www.flu.gov/pandemic/history).

The 1968-1969 pandemic presented the next largest outbreak that originated in Hong Kong. This outbreak accelerated treatment and antibiotics for treating secondary bacterial infections.

In 2009-2010 a flu virus emerged in the United States and around the world by the name of H1N1- other words known as swine flu. According to the CDC 74 countries were impacted by the virus- and within the United States 48 states were affected with an estimated 43-89 million cases of H1N1, with an estimated 8,870 and 18,300 H1N1 related deaths (http://www.flu.gov/pandemic/history/)

According to the CDC,  between 1976 and 2006, 10,000-40,000 people die each year  on average in the United States as a result of Influenza (http://www.cdc.gov/flu/about/disease/symptoms.htm).

Etiology-

The Influenza Flu is a infectious disease that has several different types: Influenza A, B or C (Influenza A belonging to the Orthomyxoviridae family). The flu is transmitted from person to person through droplets of infected hosts through coughing, sneezing, or even talking. The virus can be spread through the inhalation of droplets, or merely by touching a surface that is infected but the virus and then touching ones mouth or nose.

Clinical Symptoms- 

Symptoms of the flu can begin 1-4 days after the viruses has infected the body. This means that a healthy adult can spread the flu to others before symptoms even emerge- and are able to infect others from 5-7 days after the becoming ill. Children can spread the flu for longer than 7 days. (http://www.cdc.gov/flu/about/disease/spread.htm)

Symptoms include fever, cough, sore throat, runny or stuffy nose, muscle aches, headaches, and fatigue. Although most cases of individuals with the flu recover after the illness has run its course, some people can develop more severe complications such as pneumonia and bronchitis.

Detection Methods-

If obvious symptoms of coughing, fever, fatigue and muscle pain are not present, patients can either see a physician or get screen for a rapid influenza diagnostic tests (RIDTs), and obtain their results within 30 minutes to confirm a diagnosis. (http://www.cdc.gov/flu/professionals/diagnosis/rapidlab.htm)

http://www.cdc.gov/flu/