When I remarked that this was a busy day, early in the morning, I had no idea how right I was. The announcement (which I picked up via Twitter) of the H5N1 death in Alberta knocked everything else off the table. And after a couple of hours of reflection I think I see some aspects of the case that might be worth discussion.
We know from the CBC that the person was younger than Alberta's 58-year-old medical officer of health, and it seems likely that the person was a woman. For the sake of simplicity I'll assume she was. We also know she did not leave Beijing during her visit to China, and she did not come into contact with poultry on a farm or in a market. She may have been in contact with live poultry in some restaurant.
What we don't know is immense: Was she a tourist or businessperson from Canada, or a recent immigrant home for a holiday? When exactly was she in China, and where in Beijing did she go? What was her prior medical history? If she was starting to feel ill as she left China on December 27, where had she been 3 or 4 days earlier where she might have been exposed to H5N1? And why didn't she show the usually symptoms of cough, fever, etc.?
In some ways, her case is more alarming for the Chinese than for us. It would have been extremely unlikely for her to infect anyone else. But H5N1 hasn't been reported in humans in China for almost a year. They reported a poultry outbreak in Guizhou, far from Beijing, a week ago. China's last human cases were reported to WHO almost a year ago. Both were dead by March 12. (I can't find specific WHO reports on these cases.)
Granted, the Chinese health authorities have been distracted by H7N9 since last spring, but their relative openness about that disease suggests they would have certainly reported any H5N1 cases as well.
One of the maddening aspects of H7N9 is that it doesn't bother the chickens; they carry it invisibly right up to the end of their lives, and only rarely does a poultry dealer or customer actually catch it. So we're the canaries in Chinese poultry's coal mine.
Is it possible that H5N1 has learned this trick from its cousin H7N9? That's a very unpleasant thought.
Or are asymptomatic H5N1 carriers roaming Beijing? That's unpleasant too. One objection to H5N1's seemingly awful case fatality rate is that many people may contract it without effect. If so, then the CFR would be far lower than it currently seems to be. But very few humans have been found with H5N1 antibodies. (Granted, the first case in Indonesia, back in 2005, was a healthy labourer who was found to be carrying such antibodies.)
The Chinese must also be worrying about their surveillance methods. When the little daughter of a Beijing poultry dealer came down with H7N9 last spring, her whole neighbourhood got tested (a little boy across the street appeared to be asymptomatic). But H5N1 in Beijing seems to have eluded them.
This is also, to the best of my knowledge, the first long-distance export of an H5N1 case—exactly the kind of case we've been fretting about for years, and also the kind of case that moved H1N1 around the world so quickly in the spring of 2009.
H5N1 has so far been a disease of poor farmers and working- or middle-class Asian urbanites. Such people don't travel far. If H5N1 is showing some social mobility up into the jet set, that lends a new terror to air travel (which already has too many terrors).
Taking exams is very educational, because exams teach us what we don't know. H5N1 has just run a snap quiz on us, and we've bombed it. Back to the books.