Seasonal Influenza or "the Flu"Flu season starts in October and can continue to as late as May. Usually there are the most number of cases in January or February. Wyoming and Minnesota are already reporting cases this year. So here is what you need to know.
Seasonal influenza, commonly called “the flu” is caused by one of several influenza viruses. The flu has
symptoms like fever, headache, body ache or sore muscles, tiredness, cough, runny nose, and sore throat. Some people also have vomiting with the flu. The flu is not the same thing as a stomach bug. So vomiting and diarrhea without sore throat, cough, and/or runny nose is unlikely to be the flu.
I really hate to get the flu. I have had it twice and it puts me in bed for days. When I see patients who have the flu, they just look miserable. As a medical provider, I always order a flu test during flu season for fever with headache, body ache or sore throat. But, sometimes I feel like you can just look at a person and guess they have the flu.
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You are usually sicker with the flu than with a cold. You keep fever longer (4 or more days). You feel worse. And you are more likely to have complications from it. Each year about 20,000 children are hospitalized from flu complications like pneumonia. You might even need to take your child to the the emergency room for the flu.There are flu related deaths each year. In the 2011-12 flu season there were 34 pediatric deaths. That was a mild year. In 2009-2010 there were 282 pediatric deaths. That was an extreme year. Children under 5, adults over 65, pregnant women, Native Americans, anyone with medical conditions such as asthma are more likely to have flu complications. It is therefore more important for them and their families to take preventive measures from getting the flu. One of the preventive measures is the flu shot. In a later post we will talk about the flu shot and other preventative measures in depth.
Seasonal Influenza comes in different strains: Influenza A (H1N1, H3, H3N2v, H5N1) and Influenza B. Most rapid flu tests will indicate only flu A or B. A test must be sent to the lab to get more specific information about the strain. The CDC tracks hospital and clinic information and puts it on the internet so anyone can look and see how many cases have been reported and what type of virus is causing illness.
Viruses adapt and change to their environment. Most people are aware that one of the difficulties treating HIV comes from how quickly the HIV vaccine adapts. The influenza virus does not change as quickly as HIV, but it does adapt and there are frequently new variants. H3N2v is one of the new variants. So was H1N1 in 2009. Viruses can also become resistant to an antiviral medication, just as bacteria become resistant to antibiotics.
Because influenza is a virus, antibiotics do not speed recovery from the flu. But, there are two antiviral medications that are FDA approved for the treatment influenza: Tamiflu (oseltamivir) and Relenza (zanamivir). Tamiflu is for children over the age of 1 year and Relenza is for children over the age of 7 years. Relenza is not recommended for children with a chronic respiratory disease like asthma. Both antivirals can have side effects like nausea, vomiting, diarrhea. Tamiflu can sometimes cause people to be confused or try to harm themselves. This seems to happen more in Japanese adolescents or adults. Relenza can cause upper respiratory infections like ear infections, bronchitis, and sinus infections which is part of why it is not recommended for people with chronic respiratory illnesses.
Antivirals can reduce the symptoms of the flu and also the number of days symptoms occur. Antivirals work best when started within 48 hours of the first symptoms. For really bad cases of the flu medical providers will sometimes still prescribe antivirals even after it has been 48 hours.