Chile anthrax letters differ from US strain

Anthrax found in a letter mailed to Chile is not the same as the strain discovered in letters received in the US, investigators said.

Officials at the US Centers for Disease Control and Prevention (CDC) were not sure whether the anthrax specimen they tested came from the letter mailed to a Chilean doctor or if it was contaminated by the Chilean lab that performed the initial tests.

‘‘This strain does not match the strain associated with the contaminated mail in the United States and therefore does not appear to be linked to the situation in the United States,’’ CDC spokesman Tom Skinner said yesterday.

The anthrax found in New York, Washington, New Jersey and Florida has been linked to the same Ames strain.

The Chilean lab has anthrax on its premises and could have contaminated the specimen during the testing process, before it was sent to the CDC.

US officials have not examined the letter itself, which remains in Chile, but hope to, Mr Skinner said.

CDC officials, who planned to continue working with Chilean health authorities, want to compare the Chilean laboratory’s previously existing strain of anthrax with that believed found on the letter.

A match would suggest that positive tests for anthrax resulted from contamination inside the lab.

Dr Antonio Banfi, a paediatrician in Santiago, Chile, received the letter - with a Swiss postmark and a Florida return address - two weeks ago. Swiss police said yesterday the letter may have been mailed from New York.

The Swiss Federal Police Office said the letter was part of a large mailing sent on behalf of a Florida company by the New York branch of the Swiss Post Office.

Swiss Post International Inc provides worldwide bulk mailing services for companies. Under US rules, letters sent within the country by international post offices must carry a foreign postmark.

The letter sent to Chile bore a postmark from Zurich, Switzerland, but had no date - typical of letters sent by the New York branch, Swiss officials said.

Neither the person who opened the envelope nor 12 others who were nearby have tested positive for exposure to anthrax spores. All were given antibiotics as a precaution, Chilean health officials said.