It stood out to me as well. It’s entirely possible that Swedes in general are doing a good job of social distancing, hand-washing, etc. and the numbers are coming out of congregate care and other circumstances where they cannot distance, so it could be from poor mask discipline.

Also, it looks as though there are different strains of the virus. The one in Europe (and the US Eastern seaboard) is less transmissible and more lethal.

There’s also the issue of false positives in serological tests. The ones they are using are likely better than the ones in the US — but that’s a very low bar. I think that in the future we’ll be a good example of nationally how not to handle a pandemic. But we need to get to the future first. :-)