Influenza, or flu as it is commonly known, is a contagious disease caused by a virus. In fact, there are 4 types of seasonal viruses – A, B, C, and D. Of that, A and B can cause seasonal epidemics through circulation.

Influenza A viruses are classified further into subtypes depending on the proteins present on its surface – probably the most well-known is the H1N1 virus which caused a global epidemic in 2009.

The Influenza B virus does not have subtypes and is incapable of causing pandemics.

The Influenza C virus causes mild infections and is detected rarely; it is therefore not important from the point of view of public health.

Influenza D virus affects the cattle and usually does not cause illness in human beings.

Signs and Symptoms

Individuals suffering from seasonal influenza may experience the following symptoms:

  • Sudden onset of fever
  • Dry cough
  • Headache
  • Muscular and joint pain
  • Generally feeling unwell
  • Sore throat
  • Runny and/or congested nose

The cough is severe in some cases and can last for two weeks or even more. Patients generally recover in a week without requiring medical attention, but in some cases, it can cause serious illness – and in extreme cases, even lead to death.

However, hospitalization and death occur in people who belong to high risk groups. Globally, flu epidemics cause about 3 to 5 million cases of severe illness, and around 500,000 deaths.

In industrialized nations, people aged 65 and above are more susceptible to death from influenza. Clinics and hospitals are often overwhelmed during peak periods of the epidemic. At EPIC Health, we are on high alert during the flu season.

Risk Factors

Influenza affects individuals of all ages, yet certain groups are more at risk than others. These include:

  • Pregnant women
  • Children under 5 years of age
  • Elderly people (65+)
  • Individuals with compromised immunity, especially HIV/AIDS
  • Individuals with chronic conditions – cardiovascular, pulmonary, liver, hematologic, renal, metabolic diseases, etc
  • Patients receiving chemotherapy or steroids
  • Patients taking immune suppressants (especially after organ transplant)
  • Cancer patients
  • Healthcare providers directly working with influenza patients

Influenza is highly contagious and spreads easily. The more crowded the place, the quicker it spreads. Schools, workplaces, nursing homes, public transport, multiplexes, and other closed places packed with people are especially risky.

When a person with the flu sneezes, coughs, or even talks, they release droplets that contain the virus into the air. These droplets can travel up to 1 meter and infect anyone breathing in that radius. The flu is also spread through contamination of objects or surfaces.

For this reason, it is very important that you cover your nose and mouth with your hands, a tissue, or cloth when sneezing, coughing or talking. That’s why doctors recommend you to wash or sanitize your hand more frequently – even if you do not have this medical condition.

Seasonal influenza occurs in the winter in regions with temperate climates, but in tropical regions, it may occur any time of the year – there are more and irregular outbreaks of the illness.

The incubation period of flu – the time you get infected till the time you actually fall ill – can range from 1 to 4 days, with 2 days being the most common period.


All of this can be avoided if you simply get your annual flu shots. At EPIC Health, we advise all our patients to get flu vaccine to protect themselves and their family. This is more important if anyone in your family falls in the high risk category.

In the last flu season, the CDC reported that 56 pediatric deaths were caused by the flu, and about 20 million people reported getting the infection. While the numbers indicate that the epidemic has decreased in severity compared to the previous year, the numbers can be reduced further with vaccination.

The most predominant strain of the influenza virus in the U.S is H1N1, but the epidemic caused by this virus sub-type is less in severity compared to that caused by the H3N2 strain. In some regions of Southeastern America, the H3N2 strain is detected more frequently – this means, that epidemic varies in severity depending on the region.

The CDC recommends that everyone over the age of 6 months should get annual influenza vaccine. Getting the vaccine can help prevent infection, and decrease the severity of infection even if the virus strain is not a match to the vaccine. Young children are more likely to survive, and senior adults have less complications or need for hospitalization.

Your EPIC Health physician will not give you the vaccine if:

  • You have had a severe allergic reaction to the vaccine in the past
  • People who have or had GBS or Guillain Barre Syndrome

Have you had your annual influenza shot yet? If not, don’t worry, it’s still not too late. Simply walk into any EPIC Health Center – in Detroit, Southfield or Ferndale – and protect yourself and your family from flu.