New Anthrax Cases Confound as Fourth Victim Dies

A Manhattan Ear, Eye and Throat Hospital supply clerk who contracted inhalation anthrax died early today at New York's Lenox Hill Hospital, becoming the fourth fatality from the disease in the past month (AP/Baltimore Sun, 10/31). The New York case and a cutaneous infection in a New Jersey bookkeeper, both announced earlier this week, have prompted officials to "rethink basic assumptions about how easily [anthrax] may infect people and how widely it may have spread through the mail," the Los Angeles Times reports. Neither the New York victim, identified as 61-year-old Kathy Nguyen, nor the New Jersey woman appear to have received suspicious mail or to have spent time at a contaminated postal facility (Huffstutter et al., Los Angeles Times, 10/31). In addition, neither woman works for the postal service or in the government or media, as have previously infected people.

To determine how Nguyen contracted the infection, officials are interviewing her friends and relatives and investigating the hospital where she worked, what she did "socially and recreationally" and what transportation she used. CDC Director Jeffrey Koplan said, "We are making no assumptions as to where this exposure occurred. We are not making an immediate assumption that she was exposed at work or that it was a letter" (Pelton/Baer, Baltimore Sun, 10/31). Koplan "suggested" that the woman, who worked in the hospital's stockroom, could have been exposed through the mail because the hospital had combined its stockroom and mailroom while renovations were being completed (Dobnik, AP/Nando Times, 10/30). The New York Times reports that it might take additional anthrax cases before authorities determine the cause of the woman's infection (Broad et al., New York Times, 10/31). There have now been 17 confirmed cases of anthrax infection, 10 of the inhaled form and seven of the cutaneous version (Borenstein et al., Philadelphia Inquirer, 10/31).

Because health officials have found no direct connection between the recent cases and tainted mail nor evidence of a suspicious letter, there is "growing belief that the nascent path of anthrax infection had moved beyond media companies, government offices and mail routes, to ordinary citizens" (Steinhauer, New York Times, 10/31). During a news briefing yesterday, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said, "Until yesterday, there was no evidence that there could be or is an individual in which there might be the reasonable question: 'Did they get infected from a piece of mail that went to their home?' That is being intensively investigated right now." Homeland Security Director Tom Ridge said that he believes that home mail delivery "poses little risk for most Americans" (Baltimore Sun, 10/31). Koplan, however, said that "it pays to be vigilant and look for other letters" that could be contaminated (El Nasser, USA Today, 10/31).

Since the first case of anthrax infection was diagnosed in Florida almost one month ago, nearly every assumption officials have about anthrax has been "challenged, if not disproven outright," the New York Times reports. One of those assumptions is that a large amount of spores are necessary to bring about an inhaled anthrax infection (Broad et al., New York Times, 10/31). Results of past studies have been contradictory. Government officials have used Department of Defense research from the 1980s indicating that 8,000 spores can cause lethal infections. But a study by the World Health Organization put the number at 50,000 spores among animal hide workers, while a Journal of the American Medical Association paper suggested that 2,500 spores would cause an inhalation infection (Los Angeles Times, 10/31). Yesterday, the CDC's Bradley Perkins said that the agency does not have any information that could "offer a clear cut line that says, with X number of spores you're OK, and over that you're not" (Regalado/Hensley, Wall Street Journal, 10/31).

Matthew Meselson, a Harvard University biology professor, added, "An error in the discussion about all this is that there's a threshold dose below which the chance of infection is zero. In fact, there is no threshold. Even one spore has some probability of causing infection" (Kaplan, Boston Globe, 10/31). John Clements, chair of microbiology and immunology at Tulane University's medical school, speculated that a person's risk of infection could depend on his or her own immune system and lung capacity. He added, "It's not what we know or don't know that gets us in trouble; it's what we know that turns out to be wrong. This could be a classic example of that" (Los Angeles Times, 10/31). Michael Osterholm, director of the University of Minnesota's Center for Infectious Disease Research, said, "We are going to have to start getting used to this uncertainty in the short term, because it is going to take a while for these cases to be fully investigated" (Broad et al., New York Times, 10/31).

In other developments yesterday, trace amounts of anthrax were found in the mailroom of the Economic Research Service of the U.S. Department of Agriculture in Washington, D.C. Further, the head of the State Department's medical unit said that anthrax spores were "probably all over" its building. Traces of spores also were found at two Washington, D.C.-area postal stations -- one in the District neighborhood of Friendship Heights and the other near Dulles International Airport in Virginia (Steinhauer, New York Times, 10/31).