Two more anthrax cases in US

Anthrax may be surprisingly difficult to spread but fear is deeply infectious, America is learning, as two more cases of actual anthrax infection are reported, one, a small child, in a new location, a third media company. Analysis has also confirmed the finding of anthrax in a letter to Senator Tom Daschle, the Senate Majority Leader, opened on Monday.

Police said the letter shares the same handwriting and Trenton, New Jersey, postmark as that addressed to the TV company NBC. They also say that it contained a particularly pure form of the virus, indicating sophisticated refining, unlike the anthrax found in Florida which they believe to have been in a naturally occurring form not produced in a lab.

To date five confirmed anthrax attacks have been made - on American Media in Florida, NBC and ABC in New York, on Microsoft in Reno, Nevada, and Mr Daschle in Washington. Four people have been confirmed to have been infected.

Yesterday's developments suggest at least two different modes of attack, and hence perhaps attackers, but as yet there is no evidence of who might be responsible.

Throughout the country businesses and public offices were tightening up on post-room procedures and there were many signs of just how jittery the public is. FBI officials say they have responded to nearly 2,300 anthrax-related threats since September 11th, burdening investigators with a flood of hoaxes and false alarms, each of which has been evaluated.

Pedestrians walking down the street in New York were filmed by one TV station going out of their way not to handle leaflets being handed out.

The seven-month-old baby boy of a freelance ABC TV producer was apparently infected with cutaneous (skin) anthrax on a visit to the company in New York on September 28th, while a post-room employee in American Media Inc, in Florida, previously thought only to have been exposed has contracted the more serious inhalation anthrax.

Mr Ernesto Blanco (73) "is improving and the public health officials are encouraged by his progress," officials said in a statement. Another American Media employee, Mr Bob Stevens, died of inhaling anthrax on October 5th. Six others have shown positive tests for exposure but not infection. Police announced they had found "miniscule" quantities of anthrax spores at the Boca Raton post office where American Media's mail is sorted. The baby boy is also reported to be recovering. Police were conducting thorough sweeps of other media offices, those of CNN, CBS, Associated Press, the New York Daily News, Fox News and the New York Post. On the Hill they sealed off eight floors of the affected Congressional building to test its shared ventilation system.

The authorities insist that they have as yet sparse evidence of connections between the anthrax incidents other than the Trenton handwriting link between two of them, and no evidence of a link to the al-Qaeda organisation. Investigators appear to be divided on the possibilities of the latter, with media reports citing off-the-record sources supporting both the idea of a link with September 11th and others, one or more opportunist home-grown terrorists.

The difficulty of obtaining anthrax, particularly in refined form, and the Trenton postmarks suggest some degree of sophistication and co-ordination. New Jersey and Florida, where the first letter was mailed, were also known to have been locations where the September 11th hijackers lived before the attacks.

Malaysia, where the Reno letter came from, has significant bin Laden connections and one of the hijack pilots was filmed on a surveillance video meeting an al-Qaeda member in Kuala Lumpur in January. The evidence is very circumstantial.

Terrorism experts note that the anthrax attacks so far bear little similarity to the types of the larger and more deadly terrorist operations characteristic of bin Laden.

Although a former al-Qaeda operative has testified that the group experimented with deadly chemicals such as cyanide in training camps in Afghanistan, its efforts have been clumsy and it so far has not been linked to an actual attack using chemical or biological weapons. Bin Laden operatives are said to have tried, but failed, to buy anthrax and other harmful bacteria several years ago in Czechoslovakia, according to US intelligence officials.

"It just doesn't have the fingerprints or the pattern of a bin Laden operation," Mr Vincent Cannistraro, a former CIA counter-terrorism officer who has been studying bin Laden for a decade, told the Washington Post.

But Federal authorities say they are investigating the possibility that al-Qaeda was behind the attacks. The Attorney General, Mr John Ashcroft, is said to have demanded, along with the FBI director, Mr Robert Mueller, a full investigation into whether terrorism is behind the anthrax incidents. "There isn't any hard evidence of a link of any kind," the President's National Security Adviser, Ms Condoleezza Rice, said. "But we don't want to be blind to that link. It would be hard to be blind to that link, given what happened on September 11th. But there isn't any hard evidence at this point."