That's it -- thank you. The way the article was written, I had unthinkingly imagined them interviewing Tsonas about the diagnosis first and only then finding it among Alhaznawi's possessions. But it must have been the other way around.
[The sheer number of prescriptions for routine antibiotics in the S. Florida area in, say, the 6 months preceding the anthrax mailings must have been huge. Tsonas was interviewed in October. It's inconceivable that they went through all the prescriptions and the corresponding diagnoses in just a couple of weeks; it doesn't sound like a computer search would be of much help when the patient presents with a supposed bump from a suitcase. But your explanation makes sense.]
At this point, it's natural to ask if there were other cases of anthrax treated among the hijackers.