What is Influenza ("The Flu")?Influenza is a respiratory virus that causes illness characterized by fever, runny nose, cough, body aches and sore throat. It occurs as two forms, influenza A and B, both of which can mutate (change genetic makeup) from year to year. Influenza A viruses are categorized into subtypes on the basis of two surface proteins, hemagglutinin and neuraminidase. Influenza B undergoes less mutation than Influenza A, and is not categorized into subtypes. Influenza C causes only mild illness and is not categorized into subtypes.
Wild birds naturally carry Influenza A, but don’t normally become sick as a result of it. Domesticated birds, such as chickens, can become very sick as a result of Influenza A. Some subtypes of the Influenza A virus can infect both birds and humans -- this is the major concern for avian flu or “bird flu”. Pigs (“swine flu”) and dogs (“canine flu”) can also be infected by Influenza A subtypes -– these forms don’t normally infect humans, but reports of animal to human transmission, and human to human transmission, have occurred.
Normally, symptoms from influenza infection resolve without treatment in healthy people within a matter of days. However, people with chronic heart and lung diseases, diabetes, the elderly, and young children are at risk of complications from influenza infection. Complications, including bacterial infections and pneumonia, resulting in hospitalization and even death, can occur, particularly in these high-risk groups.
What Happens in Asthmatics When They Get the Flu?Influenza infections are well-known to cause worsening asthma symptoms in people with asthma. Symptoms may include shortness of breath, coughing, wheezing and chest tightness. Complications from influenza infection are more common in asthmatics than in people without asthma, and may include severe asthma attacks, pneumonia, and may result in hospitalization and even death if untreated.
How Can The Flu Be Treated in People with Asthma?The best way to treat influenza infection is to prevent it from occurring in the first place. Each year, a flu vaccine produced against the most likely subtypes of influenza A and B is available, and is recommended for people with high-risk medical conditions such as asthma. This vaccine has been shown to prevent or reduce the severity of infection as well as the complications from infection. Vaccination should be given annually in order to provide protection against that year’s influenza subtypes as well as to provide a boosting effect, as protection from the vaccine begins to fade after one year.
In addition, good hygiene can be helpful in preventing influenza. Frequent hand washing, or the use of alcohol-based hand cleaners (such as Purell), can help prevent the transmission of the influenza virus. People with influenza infection should minimize going to public places, should cover their mouths when sneezing or coughing, and should avoid sharing food and drink with other people.
However, since many people don’t get influenza vaccinations, and because these vaccinations aren’t perfect, asthmatics do become infected with the flu. Many medications are available for the treatment of influenza infections which have been shown to reduce the severity and duration of symptoms when taken within 48 hours of the start of the illness. These medications can also be used to reduce the chance of infection when someone is exposed to a person with influenza.
Don't miss the next page: Medications for Influenza.