The Health Gazette : Influenza

Influenza

Preventing Flu

Getting a yearly flu shot can prevent influenza (flu). This is one of the easiest things we can do for our health. Flu shots reduce days missed from work, doctor visits and decrease hospital admissions. It is a win-win situation for everyone. Yet, it is still difficult to convince patients to come in for that yearly shot. Hopefully, the following discussion will convince you to get your flu shot this flu season.

The flu season will be upon us before long, so I thought I would discuss influenza A. Influenza A is a common viral infection that is commonly referred to as the “flu.” It has been around for years and sends fear through our spines when we hear it is going around. This fear is based on the deaths that it causes every year and the time that is lost from work. The worst epidemic was in 1918-1919 when over 500,000 people died in the United States and twenty million people died worldwide. Deaths are usually caused by complications of the flu, such as pneumonia. Healthy individuals rarely die of the flu, but they may be fairly miserable for up to a week or so. Usually, about 25,000 people die every year from complications of the flu. Flu epidemics usually occur from December through February, but several years ago it started in September. In any given year about ten to twenty percent of the population will become infected. Approximately one percent of those infected will need to be hospitalized and eight percent of those hospitalized will die. Influenza accounts for millions of days lost from work each year.

Etiology

Influenza A is caused by a virus that is able to change slightly from year to year so that a new vaccine has to be given every year to maintain protection. Viruses are very small germs that are much smaller than bacteria. Viruses are responsible for the bulk of colds and other childhood illnesses. Bacteria cause illnesses like “strep throat,” ear infections and sinusitis. There are several strains of Influenza A that commonly cause the “flu.” Influenza B is also responsible for a flu-like illness, but it is not as severe as the Influenza A strain.

Symptoms

The symptoms of Influenza A are fairly typical and initially consist of fever, muscle aches, headache, malaise and a dry cough. Following this is a sore throat, runny nose and sometimes nausea and vomiting. Influenza is spread from person to person by direct contact or articles recently contaminated by nasal secretions. People are infectious from 24 hours before the onset of symptoms until about seven days after the infection starts. The incubation period is one to two days.

Complications

Common complications of influenza are pneumonia, ear infections, sinusitis and bronchitis. Less common complications are Reye’s syndrome, Guillain-Barre syndrome and severe inflammation of the heart muscle.

Treatment

Treatment of influenza is generally symptomatic, meaning plenty of fluids, bed rest and acetaminophen (Tylenol). Aspirin should not be given to children because it increases the chances of getting Reye’s syndrome, which is a potentially fatal complication of influenza. There are two antiviral agents that can be used to actually treat influenza. They are Tamiflu and Relenza. Unfortunately, they must be started within 48 hours of the onset of influenza symptoms or they are not effective. Most patients don’t come in until after they have had the symptoms for several days. This is one case where a person cannot come in too early to be treated. These antiviral agents can shorten the course of the illness as well as reduce complications. The vaccine for influenza is about 70 % to 80 % effective.

The flu shot must be given every year since different strains tend to go around each year and we don’t seem to be able to maintain protective antibodies for over a year or less. It takes about two weeks for our bodies to develop protection from influenza after being given the vaccine, so we can’t wait until the epidemic is upon us to get immunized. It is now recommend that patients get immunized starting in September. For the 2013-2014 flu season there are two main flu shots. There is the usual Trivalent vaccine containing  two vaccines against influenza A and one vaccine against influenza B.  This year we have a  new Quadravalent  vaccine which contains the same strains as the trivalent but includes another influenza B strain for a total of 4 strains. The choice of what vaccines to use each year are based on global influenza virus surveillance. They have been very accurate in predicting what strain will predominate in any particular year.

Side Effects

Significant side effects of the flu shot are unusual and generally mild. Pain at the site of injection is the most common, followed by fatigue, muscle aches and fever. In spite of what is commonly said, the flu shot is totally incapable of causing the “flu.” The vaccine is composed of dead particles of the influenza virus and is incapable of causing infection. When you develop a “cold-like” illness following vaccination it is purely a coincidence. This also could be related to individuals getting the vaccine after the epidemic has already started, and they are incubating the virus at the time they get the vaccine. Since it takes two weeks for the vaccine to be effective, they would not be protected at all and certainly could get the flu. They could also just be getting a cold at the time they get the vaccine. Having an allergy to eggs is no longer a contraindication to getting a flu shot. A study in the New England Journal of Medicine, showed that the side effects of a flu shot are almost identical to the side effects of a placebo injection, with the exception of arm soreness which was higher in the individuals that actually received the flu shot.

The flu vaccine is recommended for all individuals over six months of age.

Benefits of the Vaccine

A study in the New England Journal of Medicine showed that getting the flu shot will:

Reduce the number of doctor visits for “colds” by 44 percent.

Reduce sick days from work by 43 percent.

Reduce the total number of reported “colds” by 25 percent.

 


 

The information provided above is offered as a community service about health-care issues and is not a substitute for individual consultation. Advice on individual problems should be obtained from your personal physician. This information is based on research by the author and represents his interpretation of the literature.