You go to the doctor with the following symptoms: fever, cough, sore throat and muscle aches. Just typical flu symptoms, right?
Most likely, yes. But those same symptoms can indicate avian flu in humans. With fears about the H5N1 virus spreading from Asia to Europe, health officials in the United States are preparing for a worst-case scenario: a global pandemic in which the virus would mutate and spread easily from person to person.
"One challenge is that this disease [avian flu] presents initially as the ordinary yearly variety of influenza," said Dr. Pascal James Imperato, chairman of the department of preventative medicine and community health at SUNY Downstate Medical Center.
While Imperato said health care providers should become informed so they're ready to deal with avian flu, there is no need for panic.
The H5N1 virus would have to undergo a significant genetic change to become easily transmissible from human to human, said Imperato. So far, that hasn't happened.
Since 1997, there have been about 100 confirmed human cases of avian flu diagnosed worldwide, most of them in Asia and the Middle East, and nearly all those who caught the virus were infected by handling or eating infected poultry.
Jennifer Morcone, public affairs officer at the Centers for Disease Control and Prevention, said that, at this point, doctors could diagnose avian flu by closely watching the progression of the disease in patients. If it's seasonal influenza, symptoms would likely resolve themselves quickly and in a more predictable way; if it's avian flu -- at least as it has manifested itself so far -- they'd get more severe over time.
And if a doctor in the United States thought she saw a case of avian flu in a patient, Morcone said the doctor would need to take a thorough medical history to see if the patient had recently traveled to Asia or had any contact with sick or dead poultry.
"It would be unlikely to see clusters of the disease here before we saw it elsewhere," Morcone said.
If a doctor suspected a human case of avian flu, she would conduct a nasal swab to collect and test mucus for the virus. The current test for H5N1 takes two to three days for results, but the Food and Drug Administration recently approved a test that would give results in four hours.
At this point, the CDC recommends that doctors consider testing for avian flu on a "case-by-case basis in consultation with state and local health departments."
Imperato emphasizes that a human strain of avian flu could look very different from the way the virus looks now, but he said that physicians would have a very specific set of directives from the CDC and other government health officials on what to look for and what to do.
The reported symptoms of avian influenza in humans have ranged from typical flu symptoms to eye infections (conjunctivitis), pneumonia, acute respiratory distress, viral pneumonia and other severe and life-threatening complications.
Though the symptoms can look similar, below are some ways to distinguish between the typical, seasonal flu and avian flu.
Typical seasonal flu
Less virulent and less likely to cause severe illness because many people will have partial immunity
Illness normally lasts one to two weeks
Less likely to cause pneumonia early in the illness, if at all
Most severe for the youngest and oldest of the population
Normally strikes in winter and includes just one wave
Avian flu attack attack
Expected to be more severe because humans have little or no immunity to it
Illness is expected to last for several weeks
Leads to viral pneumonia in the first two days of the illness
Would be severe for all ages
Strikes at any time of year and comes in multiple waves
Strikes 15 percent to 30 percent of the population