About as many Americans die of influenza each year as are killed by breast cancer. But only with some unusual event -- the movement of the avian flu or a shortage of vaccine does the public typically take notice. The flu is not just an aggressive form of the common cold. Even in an ordinary year, millions spend several days bedridden with aches, fever and coughing.
We have 36,000 people in the U.S. dying every year of flu, but we have millions of people who get infected with the flu, and therefore its both a minor problem and a major problem, said Arnold Monto, MD, professor of epidemiology at the University of Michigan School of Public Health and an internationally known flu expert.
Many of us refer to the flu as though its a single virus, but it is actually several different types and subtypes of related viruses that undergo constant genetic changes. These changes are why you need a new shot every year.
Every few years, one of these flu bugs makes a major genetic leap and becomes a form of flu no human immune system has ever encountered and for which there are no known vaccines.
The virus the world flu experts are watching right now is called H5N1 influenza, known informally as avian flu or bird flu. If the flu bugs we see in a regular year are handguns, H5N1 is an AK-47.
H5N1 has killed about 60 percent to 70 percent of those whove been infected in Asia, and birds carrying the virus have recently been found in Romania and Turkey, showing its moving west.
This is a severe disease. It is not typical flu. It starts out with pneumonia, whereas in many cases flu may develop into pneumonia but most of the time it doesnt, Monto said. It also moves throughout the bodys organs and becomes whats known as a systemic infection.
What were concerned about is the potential that this virus can change in one way or another and become able to transmit from person to person, Monto said. Most of those who have contracted H5N1 have gotten it from infected birds, not from other people.
Even if this doesnt occur, were long overdue for a pandemic, Monto said. We all know the lessons of not being prepared and we have to prepare and be ready for this because even if this is not the virus that starts causing the pandemic, another one will.
When disease is widespread in several countries it is called a pandemic including the flu pandemic of 1918, which killed 40 million people worldwide.
Pandemics are not a one-time flukes, Monto said. People now travel internationally much more than in 1918, or even than 1957 and 1968, when pandemics struck. That boosts the likelihood that a new form of flu could spread around the world before health officials even know what's happened.
Scientists are working to develop a vaccine against the bird flu, and Monto said this years flu vaccines arent expected to offer protection against H5N1; the three strains it aims to ward off are too different from H5N1.
Still, Monto advocates vaccination as one simple way to gain protection against flu, adding that its not a good idea to only get vaccinated when it looks like an especially tough flu season is on the horizon.
You may get the flu one year out of five or one year out of 10, depending on your age group and who youre exposed to, he said. But when you do get flu, you really are incapacitated.
If you make it a habit to get vaccinated for flu, you should get vaccinated for flu whatever the predictions for that particular year, he said. You shouldnt play Russian roulette with predictions about whether its going to be a bad flu year.
In addition, Monto suggests fighting flu with an antiviral drug, which is similar to treating an infection with an antibiotic. One important distinction is that antivirals like Tamiflu® and Relenza® are only effective against influenza if taken within the first days of illness.
Antivirals can shorten the duration of flus symptoms and prevent some complications like ear infections in children, Monto said. He added that the U.S. and other countries are stockpiling antivirals in the hope that they can interrupt the wildfire spread of a new, aggressive flu against which there is no vaccine.
The Centers for Disease Control and Prevention estimates that 5 percent to 20 percent of Americans come down with the flu during each flu season, which typically lasts from November to March.
The CDC estimates that more than 200,000 Americans are hospitalized and about 36,000 people die from the flu and its complications every year.
Children are two to three times more likely than adults to get sick with the flu, and children frequently spread the virus to others.
Symptoms of flu include: fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, and muscle aches. Children can have additional gastrointestinal symptoms, such as nausea, vomiting and diarrhea, but these symptoms are uncommon in adults. Although the term "stomach flu" is sometimes used to describe vomiting, nausea or diarrhea, these are rarely related to influenza.
The main way that influenza viruses are spread is from person to person coughing and sneezing respiratory droplets.
Besides getting vaccinated against the flu, you can also protect yourself if you wash your hands often and avoid touching your eyes, nose or mouth. Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose or mouth.
Most healthy adults may be able to infect others beginning one day before symptoms develop and up to five days after becoming sick. You can help stop the spread of disease by staying home when you are sick and covering your mouth and nose with a tissue when coughing or sneezing.
Source: University of Michigan School of Public Health