NYDailyNews

Docs Asking, How Did Spores Get Out?

By SUSAN FERRARO Daily News Staff Writer

edical investigators scrambled yesterday to determine how postal workers contracted anthrax when they may have only momentarily handled an envelope or simply been in the same room with a contaminated letter.

"The person has to breathe the spores," said Curtis Allen, spokesman for the federal Centers for Disease Control and Prevention.

And they need to inhale more than just a few spores. To contract inhalation anthrax, the most deadly form, infection requires 8,000 to 10,000 of the microscopic spores breathed into the lungs. Studies show that 500 spores inhaled over eight hours do not cause the disease.

Experts suggested four ways that the poison letters could infect handlers with anthrax:

Leaks. "A sealed envelope is not really sealed, it's sealed so a piece of paper doesn't come out," said Dr. Stephen Baum, chief of medicine and an infectious disease specialist at Beth Israel Medical Center.

"Say you had a lot of powder in an envelope, and you manipulated it — turned it around ... picked it up, dropped it — you would see powder come out," said Dr. Bruce Farber, chief of infectious diseases at North Shore University Hospital in Manhasset, L.I.

Once out, spores in powder can float in the air, Farber said.

Spore penetration. Very tiny spores might go through the envelope, said Dr. Philip Tierno, a microbiologist and immunologist at the New York University and Mount Sinai schools of medicine.

"Small spores, and these are said to be 1 to 3 microns across, which are extraordinarily good spores, can have dispersal in the air," Tierno said. "It doesn't take a great deal of pushing to move the spores out."

Outer exposure. "Sloppy handling" by the terrorist could contaminate the outside of the envelope and lead to inhalation anthrax "if the worker looked at the envelope to clarify a street address and whiffed it," Tierno said.

Damage. Tears from mailroom machines could let spores escape, he said. In New Jersey, postal officials said samples showing anthrax in the Trenton post office came from sites along the path letters travel in mechanized processing.

The idea that an envelope could contaminate other mail in a sack or during the sorting process is equally disturbing. But Charles Haas, an environmental risk expert at Drexel University in Philadelphia, said that while it's theoretically possible some spores could get on other envelopes during sorting, the likelihood of people becoming ill from such an indirect and extended route is remote.

Anthrax does not infect by blood, and the blood supply is safe, said Dr. Robert Jones of the New York Blood Center. To be on the safe side as the crisis develops, the Food and Drug Administration has put out new rules to blood banks, barring anyone with suspected anthrax or undiagnosed skin lesions from donating.

-- Anonymous, October 23, 2001