A 94 year old woman has become the fifth person in the United States to die of inhalational anthrax in recent weeks. The case has deepened the mystery about the bacteria's source and raised troubling questions about whether more cases are looming.
The woman, Ottilie Lundgren, was a resident of Oxford, Connecticut, a rural farming community of 9000, 30 miles from Hartford, the state capital. For the past year, she was increasingly home bound, only occasionally going to church, the public library, or the beauty salon. She had no connection with the media or politics, and why she should have been targeted or infected with anthrax has baffled both investigators and members of the normally quiet Oxford community. Moreover, preliminary tests of her home, mailbox, old mail, and accumulated rubbish have produced negative results for anthrax spores, and no anthrax has been found in the nearby postal facilities of Oxford, Wallingford, and Seymour.
Soil samples are also being taken to exclude old livestock contamination in this farming community. None the less, because only 18 cases of inhalational anthrax have been recorded in the United States in the past 100 years, bioterrorism is still suspected as the source. Three of the four other deaths from inhalational anthrax have been linked directly to contaminated mail.
Ms Lundgren's case bears similarities to that of Kathy Ngyuen, the 61 year old stockroom worker at a New York hospital who died of inhalational anthrax last month. Despite intense investigation, the source of Ms Ngyuen's infection is still unknown. The two cases raise the possibility of cross contamination of mail and of anthrax spores randomly becoming an aerosol.
At a town meeting in Oxford, Dr Eric Mast of the Centers for Disease Control and Prevention (CDC) told residents that it was unlikely that cross contaminated mail was a major problem as scientists would have expected more infections if this were a substantial risk factor. The CDC's website states, however, that the incubation period for anthrax ranges from a few days to two months and that host factors, virulence factors, and whether an individual is taking antibiotics moderate infectivity.
So far, 18 cases of anthrax have been confirmed, including the five deaths. All the cases showed an identical strain of the bacteria. In the wake of the new cases, doctors and hospitals have been advised to review the deaths of patients admitted with pneumonia and flu-like symptoms for possible missed cases.
Meanwhile, another letter laced with anthrax has turned up in Senator Patrick Leahy's office. The letter, containing an estimated 20 000 spores, was addressed in the same hand and had the same fictitious return address as that received in Senator Daschle's office. Like the letter to Senator Daschle, it was postmarked 9 October from Trenton, New Jersey. The letter to Senator Leahy was found in a quarantined pile of mail destined for the Senate. Traces of anthrax were recently uncovered in the offices of Senator Edward Kennedy and Senator Christopher Todd as well as in education department offices. A letter received in Santiago, Chile, addressed to a paediatrician at a hospital in Santiago, has also tested positive for anthrax. That letter had a Florida postmark but a Swiss return address.
The Federal Bureau of Investigation believes that all the anthrax tainted letters received so far in the United States were sent by the same person, and it has released a psychological profile. The FBI believes that the sender is a meticulous male and a loner, with a scientific background. The profile can be viewed at its website (http://www.fbi.govwww.fbi.gov) and was based on an analysis of the letters' content and handwriting.