NOT MANY PEOPLE caught the flu in Australia over the past few months.
This seemingly irrelevant piece of information should be good news to Americans. Specialists say it suggests the United States will not face an influenza epidemic when flu season begins this winter.
``Influenza A is incredibly widely traveled,`` explains Dr. Steven R. Mostow of the Rose Medical Center in Denver. ``The virus circles the world every year. We can usually judge how we are going to do during the winter in the United States by monitoring influenza cases in Australia during their winter.``
``It is difficult to predict flu seasons in advance, but we can make an educated guess it will be mild this year based on our surveys in other parts of the world,`` concurred Nancy Arden, an epidemiologist at the federal Centers For Disease Control in Atlanta. ``Which is not to say they can`t surprise you.``
Even though there may not be an epidemic, the flu this year still is expected kill some 10,000 people--most of them old or suffering from other diseases. Another million or so people will be stricken with the sickness, according to the American Lung Association.
The word ``flu`` has become a catchall word referring to a number of ailments. But the real thing is caused by a pesky, hardy virus called influenza A, say doctors.
The virus is transmitted when an infected person coughs up the virus and another inhales it. Once in the respiratory tract, the virus invades cells that clear the lungs of particles and pollutants.
The body`s immune system rushes to the defense, causing a high fever and the aches, pains and exhaustion familiar to anyone who has suffered through it. Older or sick people sometimes cannot fight the virus--their lungs fill with liquid and they die of pneumonia.
The flu virus follows the winter around the globe, carried via automobile, ship and airplane. Some doctors believe migratory birds may even spread the virus, although others dispute this theory.
``Influenza used to move at a slow and steady pace until 1957,`` said Mostow, an expert on the subject. ``That was about the time air travel became commonplace. Our records show it spreading much more rapidly and sporadically from then on.``
Once the body has encountered influenza A, it builds up a resistance to the virus and cannot be infected by it again.
But every few years influenza A mutates, creating a new virus to which no one is immune. The result is a flu epidemic throughout the world, followed by a few more stable years until the virus changes again.
The mutation usually occurs in China and doctors are not sure why, said Mostow.
Some believe it is because Chinese in rural areas bring domesticated animals into their homes during winter. The animals are safe from the deadly winter cold and, in turn, warm the house with their body heat.
``A mutation occurs when influenza A `mates` with an animal virus,``
Mostow said. ``I believe farmers in China may be exposed to influenza A at the same time they have an animal virus in their system. A mutation occurs within them and it is spread to the next town. The whole process starts again.``
In the past decade, doctors have improved a vaccine to combat the flu they say could save thousands of lives. Earlier flu vaccines were associated with unwanted side effects, but those problems have been eliminated in the new vaccines, according to representatives of the American Lung Association.
The association is launching a media campaign to urge the elderly and sick to get vaccinated this month. It estimates there are 43 million Americans who could die if exposed to the flu, including the elderly, people with kidney and heart diseases, diabetics, those with asthma, people undergoing cancer therapy and children with cystic fibrosis.
The CDC estimates only 20 percent of those who should be vaccinated actually get the vaccine.
For the healthy thousands who will get the flu this season, they can expect four to five days in bed, say doctors. They will shed the virus to others from the moment they first feel achy until four days later and it may take as long as six weeks to completely shake the lingering exhaustion that follows an attack.
Currently, they can do little more than sweat the flu out. But a drug called Amantadine is available to alleviate flu symptoms in half the time, said Mostow.
``Research is progressing because we`re taking the flu a lot more seriously,`` he said.