Influenza

A VACCINE PREVENTABLE ILLNESS

Identification and Definition

  1. A highly contagious viral infection of the respiratory passages causing fever, severe aching, and catarrh, and often occurring in epidemics.


History of Influenza

Influenza viruses are enveloped viruses of the family Orthomyxoviridae that con- tain a segmented RNA genome. Of the three types of influenza viruses, A, B, and C, the first two are associated with significant seasonal morbidity and mortality. Increased mortality during influenza epidemics results not only from pneumonia and influenza but also from cardiopulmonary and other chronic diseases that can be exacerbated by influenza (Cox, 2000).


Cox, N. J., & Subbarao, K. (2000). Global epidemiology of influenza: past and present. Annual review of medicine, 51(1), 407-421.

Flu Symptoms

  • A 100* F or higher fever or feeling feverish (not everyone with the flu has a fever)
  • A cough and/or sore throat.
  • A runny or stuffy nose.
  • Headaches and/or body aches.
  • Chills.
  • Fatigue.
  • Nausea, vomiting, and/or diarrhea (most common in children)

Complications of Influenza

For most people, influenza resolves on its own, but sometimes, influenza and its complications can be deadly. Possible flu complications include viral or bacterial pneumonia, dehydration, and ear infections and sinus infections, especially in children. The flu can worsen long-term medical conditions, like congestive heart failure, asthma, or diabetes.


You might also have muscle inflammation (myositis), problems with your central nervous system, and heart problems such as heart attacks, inflammation of the organ (myocarditis), and inflammation of the sac around it (pericarditis).

Who’s Most Likely to Have Flu Complications?

  • Adults over 65
  • Children ages 6 months to 4 years
  • Nursing home residents
  • Adults and children with heart or lung disease
  • People with compromised immune systems (including people with HIV/AIDS)
  • Pregnant women

Recommended Control Measures for Influenza

The Centers for Disease Control and Prevention recommends annual flu vaccination for everyone over the age of 6 months.

Each year's seasonal flu vaccine contains protection from the three or four influenza viruses that are expected to be the most common during that year's flu season. The vaccine is typically available as an injection or as a nasal spray.

Controlling the spread of infection

The influenza vaccine isn't 100 percent effective, so it's also important to take measures such as these to reduce the spread of infection:

  • Wash your hands. Thorough and frequent hand-washing is an effective way to prevent many common infections. Or use alcohol-based hand sanitizers if soap and water aren't readily available.
  • Contain your coughs and sneezes. Cover your mouth and nose when you sneeze or cough. To avoid contaminating your hands, cough or sneeze into a tissue or into the inner crook of your elbow.
  • Avoid crowds. Flu spreads easily wherever people congregate — in child care centers, schools, office buildings, auditoriums and public transportation. By avoiding crowds during peak flu season, you reduce your chances of infection. And, if you're sick, stay home for at least 24 hours after your fever subsides so that you lessen your chance of infecting others.