Dr. Jacqueline Gerhart: What You Need to Know as Flu Season Winds Down
Madison, Wisconsin - UW Health Family Medicine physician Jacqueline Gerhart writes a column that appears Tuesdays on madison.com and in the Wisconsin State Journal. Columns are re-published here with permission.
Dear Readers: You likely have heard from the news - and maybe your doctor - that influenza is bad this year. It's true that there have been more cases and more deaths from the flu than were expected at this time in the year.
Most often, the peak of the flu season comes in February. This year, our peak may have been in January. As of Jan. 31, influenza activity and the number of new influenza cases have been declining in Wisconsin. Based on historical trends, we will likely continue to see influenza cases for another six to 10 weeks, during which time we expect them to gradually taper off.
The typical timeline for a flu illness is as follows: First, you are exposed to someone with the flu. You usually start getting symptoms within the first 24 hours of exposure. The symptoms include fever, cough, muscle aches and fatigue. Some patients also have a sore throat and occasionally diarrhea (more common in children).
Symptoms peak at two to three days, which is the same time you shed the virus. When you are shedding the virus is when you are "infectious." Your symptoms - and your infectivity - stop around Day 8.
So how do you know if you have a cold, a bacterial infection or the flu? In general, upper respiratory symptoms of runny nose, nasal congestion, ear pressure/pain and sinus pressure are from either a cold or a bacterial infection, whereas lower respiratory symptoms such as chest congestion, wheezing and difficulty breathing are often from a bacterial infection.
Fever with muscle aches and fatigue may be from influenza. But the lines may be less clear. A January report from the Journal of the American Medical Association commented on co-infection, in which people have both a viral and a bacterial infection at the same time. A study of patients in the intensive care unit found that about 18 to 34 percent of ICU patients with influenza also had a co-existing bacterial infection.
Co-infection is most common in the elderly. Making sure all patients over the age of 65 have both the influenza and the pneumococcal vaccine (which helps prevent bacterial pneumonia) can help prevent co-infection. Also, if you notice that in addition to the typical flu symptoms you also have shortness of breath, a fast heart rate or severe chest congestion, you should see your doctor.
So how can you prevent yourself from getting the flu? Wash your hands, and stay away from people who have respiratory illnesses - especially if they have confirmed influenza. If you haven't been vaccinated, do it now. It's still the best way to prevent getting the flu.
The flu vaccine being used this year is a trivalent vaccine, meaning it is made from three viruses. The vaccine is made of influenza A strain H1N1, influenza A strain H3N2 and a strain of influenza B. The vaccine is a good match this year to what is currently circulating. As of January, more than 91 percent of this year's flu cases were from viruses contained in the vaccine.
What should you do if you think you have the flu? First, stay away from others. Get a thermometer and measure your temperature. If your fever is consistently more than 100 degrees, consider being seen in the clinic as soon as possible.
Antiviral medication needs to be started within 48 hours of symptom onset (or about 72 hours after you were infected) in order to be effective. Antivirals started after that time may be helpful in hospitalized patients, but otherwise will likely not affect how long you have symptoms.
What should you do if you have already had the flu? You should still get the flu vaccine. This is because you may not have had confirmed influenza. Also, because it's a trivalent vaccine, it will protect you against at least two more types of flu you haven't yet had.
This column provides general health information and is not specific advice intended for any particular individual(s). It is not a professional medical opinion or a diagnosis. Always consult your personal health care provider about your concerns. No ongoing relationship of any sort (including but not limited to any form of professional relationship) is implied or offered by Dr. Gerhart to people submitting questions.
Date Published: 02/05/2013