CDC: Anthrax trail not yet cold

WASHINGTON, Nov. 29 (UPI) -- Frustrated federal health officials on Thursday were not ready to say the anthrax trail has grown cold, but could not point to any specific direction being pursued that could lead to solid clues as to who launched the bioterrorist attacks that have killed five people.

The latest death, on Nov. 21, of 94-year-old Ottilie Lundgren of Seymour, Conn., continues to mystify health and law enforcement investigators as clues to the possible sources of her inhalation infection are few and initial testing of her home and surrounding areas has turned up no leads at all.

"It's quite premature to suggest that the trail here is growing cold," Stephen Ostroff, associate director for epidemiologic science at the Centers for Disease Control and Prevention in Atlanta told reporters in a conference call. "This remains a very active investigation and that investigation is being done in a highly collaborative fashion between the CDC and our colleagues in Connecticut."

Saying it was important to remember that investigators have no evidence to lead them down any specific trail, Ostroff said they are looking at a potential "outdoor" exposure of some type.

"We are frustrated that we haven't been able to detect any possible traces in environmental sampling," he said. "All of us are working to try to figure out what that is telling us. Another possible explanation is ... we simply didn't sample the right place. I think we have to keep that as an alternative explanation. Clearly an outdoor exposure is among the many hypotheses that one could think about."

David Swerdlow, CDC coordinator for the Connecticut anthrax investigation, said they are retracing Lundgren's steps, looking for clues to an outdoor exposure. They also are talking to veterinarians and animal control teams to see if there have been any dead animals discovered in the past 60 days that may possibly have had anthrax. Animals outbreaks are not all that uncommon, especially in sheep.

"We haven't identified any possible cases," Swerdlow added.

The Lundgren case --- an elderly woman who lived alone and rarely went out --- has many parallels to the other unsolved anthrax death, that on Oct. 31 of 61-year-old Kathy Nguyen of New York, a hospital worker who also lived alone and had limited contact with neighbors or friends.

Neither woman had any solid connection to the obvious anthrax sources -- contaminated letters sent through the mail to government officials or the media.

Swerdlow said the Connecticut and New York investigation teams were working together very closely to look for clues that are similar in both cases. "We are certainly not finished and several tests are pending," he said.

In another anthrax case, this of a letter sent to a doctor in Santiago, Chile, that contained the pathogen, Ostroff said CDC also is working with public health officials there to try to pin down a source.

"We know that it's not linked to what's going on in the United States and we're working with them to explain what happened there," he said, adding the possibility of laboratory contamination may be one potential explanation.

The letter was received by Dr. Antonio Banfi, a pediatrician who said the parcel was suspicious because it had a Swiss postmark and stamps but a return address for Florida.

Government sources in Chile have said the technology needed to produce anthrax like what was contained in the Banfi letter does not exist in the country.

The CDC has said anthrax found in New York, Washington, New Jersey and Florida all came from the Ames strain of anthrax from the College of Veterinary Medicine at Iowa State University in Ames. But it is not uncommon for labs to share such bacteria for the purposes of research so any number of laboratories could have the so-called Ames strain.

The university has destroyed its stockpile of anthrax, which was used in the production of the anthrax vaccine.

A total of 23 anthrax infections have been diagnosed, 11 of them inhalational and the rest cutaneous, or skin anthrax infection. Everyone hospitalized for inhalation has been released and is recovered or recovering at home.