St. Luke's Hospital FAQ's for the Flu

Frequently Asked Questions

What is influenza (seasonal flu)?

Influenza is a virus which infects the respiratory tract (nose, throat, lungs). Unlike many other viral respiratory infections, such as the common cold, the flu causes severe illness and can cause life-threatening complications in some people. The symptoms include fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose and muscle aches. Children stricken with flu may suffer additional gastrointestinal symptoms, such as nausea, vomiting and diarrhea, but these symptoms are uncommon in adults.

Is it a cold or the flu?

The flu and the common cold are both respiratory illnesses but each is caused by different viruses. Because these two types of illnesses have similar symptoms, it can be difficult to tell the difference. Generally, the flu is worse than the common cold and its symptoms are more intense. Colds are usually milder, and generally do not result in serious health problems such as pneumonia, bacterial infections or hospitalizations. Specific tests, which usually must be conducted within the first few days of illness, can tell if a person has the flu.

How does the flu spread?

The main way that influenza viruses are spread is from person to person in respiratory droplets of coughs and sneezes (this is called "droplet spread"). This happens when droplets from a cough or sneeze from an infected person are propelled (generally up to three feet) through the air and deposited on the mouth or nose of people nearby. The viruses can also be spread when a person touches a contaminated object and then touches their own mouth or nose (or someone else's mouth or nose) before washing their hands.

The time from when a person is exposed to flu virus to when symptoms begin is about one to four days, with an average of about two days. Most healthy adults will be able to infect others from one day prior to becoming sick to five days after they first develop symptoms. Some young children and people with weakened immune systems may be contagious for longer than a week.

If I had the flu last year will I have immunity against it this year?

The degree of protection depends on the health of the person involved. Young and healthy people with normal immune systems will likely have a good immunity against the same or closely related strains of virus from one year to the next.

However, it is important to remember that influenza viruses are constantly changing, so antibodies made against one strain will become less effective against new strains that evolve. Additionally, there are different types of influenza viruses circulating and the same type of flu virus does not necessarily circulate each year.

So, who should get the flu vaccine?

The CDC Advisory Committee on Immunization Practices has expanded the recommendations this year. They recommend a flu vaccine for all children aged 6-59 months; adults aged > 50-64 years; healthcare personnel; close contacts of immunocompromised persons; pregnant and breastfeeding women, and anyone in the general population who wishes to reduce the likelihood of becoming sick with flu or transmitting it to others. Additionally, people who have chronic conditions such as asthma, diabetes or heart disease, because they are at higher risk for complications, should get a flu vaccine. It is also important for people who live with, or care for people at high risk for complications, to get immunized. Read the complete recommendations from the CDC.