The discovery of ricin in the Washington offices of Senator Bill Frist is a sinister reminder of October 2001, when another substance demonstrated the power of biological weapons to spread fear and paralysis.
Panic only spread when the full facts about the anthrax were known
It was a clear late autumn day when news broke that a white powder in a letter addressed to Senator Tom Daschle was infected with anthrax.
This was a substance few had heard of beyond a vague understanding that it was connected with cattle. Inevitable jokes were made.
Reporters who went up to Capitol Hill that afternoon and entered the Hart Senate building, where Tom Daschle had his offices, noticed that one corner of the nine story building was cordoned off with red tape. The lifts to that section had been taken out of action.
But there was nothing to stop people from walking through the rest of the building. I went up to the mezzanine floor overlooking the central atrium to talk to office staff who were having swabs taken from their noses and were being given an initial supply of an antibiotic drug with which we became familiar - cipro.
There was no particular air of panic or concern, just of precaution.
It was not until the next day that the full impact began to make itself felt.
By then we had learned quite a lot about anthrax. You could forget about the cattle. That kind of anthrax, acquired through the skin, was not particularly dangerous. What we found out with alarm was that the stuff could be inhaled as well and that in this form it was potentially - indeed usually - fatal.
It turned out that the powder in Senator Daschle's office had been highly milled so that the spores could actually get through holes in the envelope. It was called "weapons grade". Since the letter had been carried through the building, the whole place suddenly became a threat.
That was when the panic, though suppressed and controlled, started.
Remember, this was not long after 11 September. And the letter to Senator Daschle, as well as other infected letters to other public figures, had a curious note attached which declared "Death to America, Death to Israel, Allah is Great".
Was this part of a wider plot? Or was the wording designed to divert attention to shadowy international terrorists away from a home-grown source? To this day nobody knows.
Very rapidly, the Hart building was closed. And very rapidly, a long queue of now rather worried people formed in the Senate office next door where in a large room, naval medical orderlies had set up a much larger swab operation.
We made conversation and even a few temporary friends as the queue gradually moved along the marbled corridors. Few spoke about their underlying fear.
The procedure now was that anyone who had been anywhere in the Hart building should first have the nasal swab (involving a cotton bud being pushed right up until the tears nearly flowed) in order to determine whether any spores had been inhaled.
If they had been, it did not mean that infection necessarily followed. But just in case, a three day supply of cipro (ciproflaxin hydrochloride) was handed out. If your swab results were negative, you did not need to take any more.
It was a good procedure. It made people feel more confident.
Smattering of powder
But what was most striking to me was the power of a biological attack.
The fear induced by the silent and unseen killer not only gripped the individual. It affected a whole community. Work in Congress, one of the vital organs of the US government, came to a pause if not a halt.
It had taken only a smattering of powder. If more letters had been sent to more offices in Congress, then the whole place would have had to be evacuated. The Hart building did not reopen for three months.
What in the end was most sad was that the threat had been underestimated not just in the Hart building but in the postal sorting office which served Congress.
Two postal workers were among the five people who died from this attack.
Others who got the infection were saved by aggressive medical intervention using a combination of drugs, a valuable lesson since their survival had not been expected.
Nobody has been arrested for this crime.