CDC tips help doctors distinguish anthrax from flu

War On Terrorism

Anthrax Scare

November 02, 2001|By Jonathan Bor | Jonathan Bor,SUN STAFF

With flu season rapidly approaching, federal health officials offered tips yesterday that could help doctors distinguish between the common ailment and deadly inhalation anthrax.

Citing lessons learned from 10 recent anthrax cases, the Centers for Disease Control and Prevention in Atlanta said doctors can be assisted in diagnosing the rare disease by blood tests, chest X-rays and CT scans. One tip, however, is decidedly low-tech: A runny nose is not a sign of anthrax.

"A patient with inhalation anthrax does not have nasal congestion or a runny nose," said Dr. Julie Gerberding, acting deputy director of the CDC's National Center for Infectious Diseases.

While inhalation anthrax attacks a region outside the lungs, producing a dry cough, among other symptoms, colds are infections of the upper respiratory tract.

The CDC published the guidelines to help doctors who have been faced with an onslaught of patients complaining of symptoms such as fever, headaches and body pain, which are common to anthrax in its early stages and many other illnesses.

But Gerberding, speaking yesterday at a news briefing, said doctors should not rely on a single test to confirm or rule out anthrax. Doctors should look for "a constellation of factors," including symptoms, test results and job history.

While most of the patients with inhaled anthrax had fever, malaise, sweats and chills - symptoms common to flu-like illnesses - they all had either a normal or elevated white blood count. In contrast, patients with flu typically have a lowered white count, as their immune system launches other defenses to combat illness.

Additionally, doctors found that all of the patients with inhaled anthrax had abnormal chest X-rays or CT scans. The images showed a widening of the mediastinum - a space between the lungs - and enlarged lymph nodes in the same area.

Gerberding emphasized that doctors should obtain a work history from any patient complaining of flu-like symptoms. All but one of the people who contracted inhaled anthrax had an obvious tie to mail handling, so anyone who worked for the post office or in mailrooms should be considered at risk.

Such patients should be placed on preventive antibiotics pending test results that could confirm the disease, CDC officials have said.

Dr. Eric Toner, an emergency physician at St. Joseph's Medical Center in Towson, said the guidelines help to confirm what has trickled out from case reports published by the CDC over the past month. Doctors at the suburban hospital have already been performing chest X-rays and CT scans on patients whose symptoms would not ordinarily suggest the need for such tests.

"We certainly wouldn't be doing chest CTs on somebody with just a cough and a low-grade fever," Toner said. "This is something [that] in the past would have been unheard of. But if we're going to catch someone with inhalation anthrax, we need to catch them early."

Ever since two postal workers were diagnosed with inhaled anthrax at Inova Fairfax Hospital in Virginia, radiologists there have been sharing CT scans over the Internet with colleagues across the country. Those patients are listed in serious condition.

Dr. Elias Zerhouni, a professor of radiology at the Johns Hopkins School of Medicine, said conventional X-rays might show the chest abnormalities. But if they don't, doctors should consider CT scans because the technology shows the anatomy in finer detail and might pick up defects that the X-rays missed.

Across the country, doctors are bracing for the onset of flu season, which could bring thousands of patients whose symptoms will have to be more carefully evaluated than ever. Flu season usually begins in December, stretching into March.

"We're about to enter the flu season, so there are going to be a lot of people with symptoms and signs, and there is going to be this nagging concern," said Dr. Brian Browne, director of emergency medicine at the University of Maryland Medical Center.

The CDC announced this week that the nation has its largest supply of flu vaccine ever - some 85 million doses. Last month, health agencies were urged to offer it to people at highest risk, including the elderly and people with chronic illnesses such as heart disease.

Now, the flu vaccine is being suggested for healthy people between the ages of 50 and 64. Though it is not recommended for younger, healthy people, nobody is being turned away, according to the CDC.

But people should not get a flu shot thinking that the vaccine would reduce the frequency of symptoms that can be confused with anthrax, said Dr. Keiji Sukda of the CDC. While the vaccine is about 90 percent effective in preventing influenza, it does nothing to prevent more common viral illnesses that produce many of the same symptoms.

The best reason to get a flu shot, he said, is to prevent flu, an illness that kills 20,000 people in the United States each year.

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