Symptoms of Anthrax and Flu Overlap

B O S T O N, Oct. 26, 2001 -- Fever, body aches, cough, congestion, joint pain and stiffness — symptoms of the average flu, or warning signs of the more serious, even deadly, inhalation anthrax disease?

After the deadly inhalation anthrax case of a Washington, D.C., postal worker was misdiagnosed as flu, it seems Americans may be in for a nerve-wracking flu season. And experts are trying to underscore the message that extra vigilance will be needed this year.

Major Differences

While both the flu and inhalation anthrax can inflict calamitous damage to the body, they are vastly different germs.

The flu, or influenza, is a respiratory infection caused by a variety of contagious viruses. It is spread through coughing and sneezing and includes symptoms such as headache, chills and dry cough, fever and body aches as well as upper respiratory symptoms such as nasal congestion and sore throat.

Anthrax, by contrast, is caused by the bacterium Bacillus anthracis. It can lead to infection when spores of the bacterium are inhaled. Initial symptoms of inhalation anthrax may resemble a common cold. These symptoms may then decline for a short period, after which breathing problems and shock become a cause for concern.

Physicians battle hundreds of thousands of cases of flu each year in the United States alone. But before the recent cases in Florida, inhalation anthrax had not been seen in this country in 25 years, which only makes the already daunting job of distinguishing overlapping symptoms of anthrax and the flu a greater challenge.

"We're having to learn about the disease as we go along; there have been so few cases in the world," says Dr. Adrian Long, medical director of Kaiser Permanent Mid Atlantic, "We're in uncharted territory."

Kaiser's physicians are currently treating the two D.C.-based postal workers who came down with inhalation anthrax infection a few days ago.

In the cases of inhalation anthrax seen by Kaiser, Long says that general aches, profuse sweating and other flu-like symptoms existed with both patients. At the same time, one patient had respiratory symptoms, the other did not.

"From the cases we've see, the symptoms are not following the textbook definition [of anthrax]," says Long.

The Power of Profiling

It is for this reason that Long and other health professionals urge physicians to consider each individual case.

"It's all in the history," explains Dr. Richard O'Brien, a spokesperson for the American College of Emergency Physicians who practices in Scranton, Pa. "Where does the individual work? Where have they been? How at risk are they of being exposed to anthrax?"

Without such context, or "profiling," differentiating between anthrax and the flu is a considerable task for the physician. As Dr. Stephen Aronoff, chief medical officer at Temple University Children's Medical Center explains, "The index of suspicion is critical. I can guarantee you right now that if a postal worker from New Jersey shows up with a cough, he's likely to wind up in the hospital."

The daunting task of sorting out symptoms between the two deadly diseases is also aided by modern medical science.

Chest X-rays can aid diagnosis by detecting swollen lymph nodes in the chest of inhalation anthrax patients. X-rays are quick and convenient, though may only be useful if the patient has symptoms.

"It's a lot like taking a pregnancy test right after your honeymoon, you have to wait for symptoms," says O'Brien.

Roll Up Your Sleeves

Still, health professionals say they cannot stress the importance of the flu vaccine enough this year. They hope the vaccine can help calm people's fear of anthrax as well as make their job of diagnosis easier.

Long says that Kaiser is looking into a rapid flu screening test that produces results in two to three hours to contend with the problem. The HMO is also ramping up its flu vaccine program and hopes to have all of their members in the D.C area vaccinated, though individuals at high risk for anthrax will take first priority.

As much as the anthrax scare has been instilling fear in recent weeks, doctors urge Americans to remember that the possibility of contracting the infection is remote.

"In general, emergency physicians are much more worried about what the flu can do to you," says O'Brien. "Let's all get flu shots, folks."