Influenza or the flu refers to a respiratory infection that can be caused by a variety of viruses. The virus will move through the air and become inhaled through the mouth or nose. Approximately 5-20 percent of people catch the flu each year in the United States. Influenza can cause a serious infection or death in newborns, the elderly and people with some chronic illnesses. The viruses that cause influenza are classified as A, B or C types, depending on how their proteins are composed. Type B viruses are the most common in humans.
All flu viruses travel in the air as droplets of moisture. It spreads when people talk, cough or sneeze, releasing this moisture. Some people inhale this moisture in the air while others touch objects like a keyboard or telephone that are covered in the virus and then transfer them to the eyes, mouth or nose by touching these areas.
The influenza virus alters and creates new strains constantly so those that have already been affected by the flu may have developed antibodies to ward of a specific type of flu virus. If you are exposed to a virus in the future that is similar to those you have experienced before or you have been given a vaccination against a certain type of flu, it will be easier for the body to fight off the infection.
The antibodies a person has developed will not be able to prevent an infection caused by new strains of the virus or subtypes of the virus that are different than those you have already been exposed to.
1. Body Symptoms
A common sign that someone is developing the flu is fever. Fevers caused by this virus can climb as high as 106 degrees F, though this particular type of fever tends to be less severe than other types. Adults also tend to experience lower fever than children when they are infected with the virus. Those infected with this type of flu will also commonly have fatigue and body aches.
2. Respiratory Symptoms
As the fever subsides, cough, runny nose and sore throat will become more common. In some cases, these symptoms can become worse, eventually developing into pneumonia or bronchitis if the symptoms are not treated. In most cases, respiratory symptoms will disappear after a week, though it is possible for the cough to last for several weeks.
3. Stomach Symptoms
Many strains of the condition will cause irritation in the stomach. Because this is so common, this particular type of flue is often referred to as a stomach flu though the virus does not specifically affect the stomach. Stomach symptoms include nausea, loss of appetite or vomiting.
In most cases, there is no need to administer medication to those suffering from the flu. If necessary, antiviral medications such as zanamivir or oseltamivir can be administered to help shorten the duration of the illness or to lower the risk of additional complications developing. Oseltamivir is taken orally and zanamivir is administered with an inhaler like you would use asthma medication. These medications can cause side effects including vomiting. Oseltamivir increases the risk of self-harm or delirium in teenagers.