Last Updated

12 Dec 2002

Source: Associate Press, March 8, 2002.

Anthrax Toll Could Have Been Worse

By PAUL RECER, AP Science Writer

WASHINGTON (AP) - Eleven people were infected with inhaled anthrax and five died in the recent terrorist disease-by-mail attacks, but a new study shows that without antibiotics it could have been far worse.

Medical statisticians analyzing the attack said that at least 17 people and perhaps as many as 50 could have become ill with the most serious form of anthrax except for the quick use of antibiotics by about 5,000 people exposed at hot spots in Florida, New Jersey and Washington, D.C.

"We found that the antibiotics cut the cases by half," said Ron Brookmeyer, the first author of the study appearing Friday in the journal Science. "That's good news. They were able to have a rapid response with the antibiotics and limit the disease."

He said the analysis established a range of probabilities. He said it showed that the most probable number of inhalation anthrax cases without antibiotics would have been 17 and that, in the worst case, the total number infected would have reached nearly 50.

Brookmeyer, a professor of biostatistics at the Johns Hopkins Bloomberg School of Medicine, said the study focused on three anthrax hot spots that were contaminated from letters tainted with anthrax spores.

The clusters analyzed were a media office in Florida, where two people were infected; a postal building in New Jersey, where two were infected; and a mail-handling building in Washington, where four were infected.

There were three other cases -- a State Department mailroom worker in Washington, a hospital employee in New York, and an elderly woman in Connecticut. These cases were not considered in the statistical analysis, Brookmeyer said, because they were outside the clustered exposures at the other three sites.

Investigators are still uncertain how the women in New York (case 22) and Connecticut (case 23) were infected. The State Department employee is thought to have come in contact with mail that had been contaminated by spores from an anthrax-tainted envelope at the central mail-handling office in Washington.

The study validates the quick response of public officials to the crisis and suggests that a rapid distribution of antibiotics is critical to limiting the disease, he said.

"Our study shows that when there is an exposure you can, in fact, prevent disease provided you get in there quick enough with antibiotics," said Brookmeyer. "The shorter we can shrink that interval, the more cases we can prevent."

Antibiotics were taken by about 5,000 people associated with the anthrax hot spots, about half of the 10,000 people nationwide thought to have taken the drugs because of the risk of anthrax. Most took the drugs for 60 days, the recommended regimen.

Some experts were concerned that people whose lungs still contained inhaled anthrax spores could come down with the disease after 60 days of antibiotics.

Brookmeyer said that, based on the anthrax disease incubation period observed in a 1979 outbreak in Russia, this is unlikely.

"There is some reassurance in our study because of the thousands of people who completed the 60-day regimen of antibiotics, few would be at risk of subsequent disease. Certainly, less than 1 percent," he said.