Last Updated

15 Jan 2003

Source: Reuters, March 8, 2002.

Potential Anthrax Toll May Never Be Known

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - The Brentwood postal worker stopped taking her antibiotics after just two weeks, despite the advice that she needed to take them for at least 60 days for protection against anthrax.

"I just didn't want to be a guinea pig," said Juanita, who asked that her real name not be used to protect her privacy. She was one of 2,100 at the Brentwood sorting center in Washington given antibiotics in October after a series of anthrax letter attacks.

She will never know whether taking pills for two weeks saved her, or whether she had a lucky escape from the finely ground spores that puffed out of an envelope.

Health officials may never know, either, how many lives were saved when antibiotics were handed out to 10,000 people like Juanita, who may have come into contact with anthrax spores mailed in letters to a Florida media company, to Senate offices and to network television news operations in New York.

At least 18 people, including a baby, developed inhaled or skin infections from the spores concealed in the letters. Five, including two postal workers at Brentwood, died.

A study published in the journal Science on Friday suggests that at least twice as many people would have become infected, with five more deaths, if they had not been given antibiotics to prevent any spores they may have inhaled from sprouting into virulent bacteria.

"The antibiotics cut the number of cases in half," said Ron Brookmeyer, a biostatistician at the Johns Hopkins University School of Public Health in Baltimore who led the study.

His is the first study to estimate how many lives may have been saved when the U.S. Health and Human Services Department and its Centers for Disease Control and Prevention distributed the antibiotics.

But it is based on statistics and not on any real measure of who may have breathed in anthrax spores.

CDC TRIED TO DETERMINE WHO WAS SAVED

The CDC has tried to get a better idea.

About 1,000 of the people who got antibiotics gave two blood samples each, which were tested to see if they had actually breathed in any anthrax spores.

People with confirmed infections develop antibodies to the anthrax bacteria, which are easy to test for. People who have been vaccinated also produce antibodies.

The CDC's top anthrax expert, Dr. Brad Perkins, said an antibody test was adapted to see if it could tell who had inhaled anthrax spores and thus been saved by antibiotics.

But it didn't work.

"We thought it was worth a shot," Perkins said.

Perkins is not sure whether the test is to blame, whether people who were exposed did not have the expected immune response, or whether the body does not detect the spores in small numbers.

The CDC is still holding on to the blood samples. It may be that other tests will be developed that can show whether someone breathed in anthrax but did not develop an infection.

"I still hold out some hope that there may be other antigens expressed on the spore that may be useful in detecting exposure," Perkins said.

It is bad news for the CDC, not least because the CDC, HHS and local health officials have been criticized for not having responded quickly enough after the attacks.

When an anthrax-laden letter arrived in the office of Senate Majority Leader Tom Daschle in October, the office building was quickly evacuated. Workers there had their noses swabbed to see if they may have breathed in spores -- the test is not terribly accurate but can give an idea of how far spores spread -- and $23 million was spent cleaning up the building.

In contrast, it took the deaths of two Brentwood workers (case 15 and case 16) to get action there. Health officials had said they did not believe the spores could leak out of an unopened letter and thus decided that postal workers were at little risk. But high amounts of contamination were found at Brentwood.

After that happened, Juanita, who works in a dusty warehouse while the Brentwood facility is cleaned up, felt she could not believe anything the government told her. She accepted the course of antibiotics she was offered, but did not finish taking the pills after learning there could be side-effects, including muscle weakness.

"I take enough risks as it is," she said. "I don't need any risks from some drug that I don't even know what it does."

The CDC has offered extra antibiotics and the anthrax vaccine to people who want to make sure their lungs did not carry any more spores, which may persist in the body for as long as three months. The agency says 192 opted for the vaccine and about 1,500 took another 40 days of drugs.