Could Mystery Anthrax Cases Be Natural?

Experts say it's possible, but not likely

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By
HealthDay Reporter

FRIDAY, Nov. 30, 2001 (HealthDayNews) -- Authorities think the two latest victims of fatal anthrax infections were murdered. But doctors acknowledge there's a tiny chance they may have been sickened by a natural source, and it's possible -- although unlikely -- that other cases have been overlooked in the last few decades.

While the public may assume that mysterious deaths always are investigated by someone, they often are quickly forgotten. "If there's no evidence of foul play or something really unusual, [authorities] may not pursue it further," says John Pape, an epidemiologist with the Colorado Department of Public Health and Environment.

On the other hand, anthrax becomes very distinctive over the course of the illness, and some experts suggest that alert doctors should have been able to diagnose it even before this year's outbreaks.

Since a case was diagnosed in Florida in October, inhaled anthrax has killed five people, all on the East Coast. Three men apparently were infected through their work -- two at a Washington, D.C., area post office and one in the mailroom at a Florida tabloid newspaper. Authorities have no idea how the two other victims, a middle-aged woman from New York City and an elderly woman in Connecticut, came in contact with anthrax germs.

While spores carrying anthrax bacteria are a natural part of the soil, they rarely make people sick, at least according to health records. For instance, this summer the Del Rio, Texas, region had outbreaks of anthrax in deer and livestock, and in January cattle in Nebraska had it; last year cattle and horses got it in Minnesota and North Dakota, according to the U.S. Department of Agriculture (USDA). Before this year, the last reported human fatality in the United States occurred in 1978. Reportedly, only 18 U.S. cases were verified in the last century.

"It's a naturally occurring disease of animals, but it's very rare in humans," says Dr. Keith Kaye, an infectious disease specialist at Duke University. "It generally occurs in people with extensive exposure to animal hides or fur, or people who work with textiles." The size of the spores -- 2 to 6 microns -- is far tinier than a human hair, but they tend to clump together and bind to soil so that even where there is a lot of anthrax in the ground, few humans tend to get the disease, according to the Centers for Disease Control (CDC). Estimates are constantly being re-evaluated, given new cases, but historically, experts have thought it would take breathing in about 8,000 spores to make a person sick.

Given the heightened awareness of anthrax, medical officials want to make sure they haven't missed any cases recently. In the wake of the death of a 94-year-old widow in Connecticut, officials are investigating 15 other recent deaths from respiratory diseases in that state.

As the public and many medical officials have learned, inhaled anthrax doesn't loudly proclaim its presence in the early days of infection. It creates flu-like symptoms that can be mistaken for those caused by other illnesses.

As anthrax develops, however, its symptoms become unique, Kaye says. "Once people develop the second stage of the disease, they have shortness of breath, abnormal chest X-ray findings, confusion and mental status changes, and appear to be notably ill. Certainly in that second stage of illness, physicians would want to institute a rapid and efficient investigation."

The chest X-rays would show widening in the mid-chest around the heart as toxins build up in the lymph system there, he says. "That's a very typical finding, and there are not too many acute infections that would give you [that]." Also, he says a bacterial culture taken from a patient should clearly show the presence of anthrax because it grows quickly.

But there are some caveats, experts say. Antibiotics could wipe out the anthrax bacteria before cultures are sent for testing, though the deadly toxins created by the germs would be left behind, Pape says.

And if someone died before anthrax was detected, no one might investigate further. "Autopsies are not commonly done in this country unless there's something suspicious about the death," and an autopsy might be especially unlikely if the victim was elderly, Pape says.

While no one has ruled out the possibility that anthrax has hit people without anyone knowing, one expert says the chances are virtually nil that the two mysterious cases in New York City and Connecticut were natural and not cases of murder.

"Two sporadic cases in 30 to 60 days in urban and suburban environments is just too much," says Dr. Don Milton, a lecturer on environmental health at the Harvard School of Public Health.

In addition, investigators have found that the same strain of the virus killed all of the victims.

What To Do

To read more about anthrax, check the CDC and this fact sheet from the USDA. The Journal of the American Medical Association and Johns Hopkins Center for Civilian Biodefense Studies have detailed rundowns, including specific treatments, for the illness.

For more on the various bioterror weapons, try the American Medical Association.

SOURCES: Interviews with John Pape, epidemiologist, Colorado Department of Public Health and Environment, Denver; Keith S. Kaye, M.D., M.P.H., infectious diseases physician and epidemiologist, Duke University Medical Center, Durham, N.C.; Don Milton, M.D., Dr.P.H., lecturer on occupational and environmental health, Harvard School of Public Health, Boston

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