Sweden saw a big jump in the number of confirmed cases today:

Sweden has seen its confirmed cases of Covid-19 jump from 16,004 to 16,755. The rise was much larger than in recent days, during which Sweden’s Public Health Agency had been cautiously celebrating a flattening of cases.

The agency’s deputy state epidemiologist Anders Wallensten said the majority of the new cases were in Stockholm. Increased testing of healthcare workers could be a factor, he said, but scientists were looking into other potential reasons.

The Swedish reporting of new cases has been extremely variable from day to day. If you look at historic charts of the reporting, you can see small plateaus where reporting would drop off for the weekends. That has made it harder to trust the day to day variation because while the numbers tended to look good on the weekend and even on Monday, there was often a surge midweek as those declines were filled in. In any case, earlier this week Sweden’s public health officials were saying it looked to them as if Sweden had flattened the curve:

Anders Tegnell, the chief epidemiologist, said the curve was beginning to flatten and had reached a “plateau” in many parts of the country, including Stockholm, the centre of the largest outbreak. The number of daily new Covid-19 infections reached a peak of 726 on April 8 before falling to 332 four days later. Since then it has inched back up to about 600 new cases a day.

Dr Tegnell said there was a “clear plateau position” in most districts. “The pressure on the intensive care units appears to be light,” he told the broadcaster TV4 over the weekend. “We hope this is a trend that will continue.”

His deputy, Anders Wallensten, struck a similar tone of guarded optimism. “We still see that it is levelling off a little,” he said. “That’s hopeful. But this is a hard time and a lot of people are getting ill . . . so the danger is absolutely not over.”

But the optimism was apparently misplaced. Tuesday the death toll jumped by 185, the highest total in a single day, and Wednesday saw the second highest jump with 172 more deaths. The number of deaths increased by 84 today bringing the total to 2,021. That’s significantly higher than any of its neighbors. The number of deaths in Norway (which has about half of Sweden’s population) stands at 191. In Denmark (a bit more than half Sweden’s population), the figure is 394.

Yesterday, Sweden’s Public Health officials retracted a study which claimed that for every confirmed case in the country, there were another 999 people who had the virus but didn’t know it. As Allahpundit pointed out even before the retraction, the “multiplier” in that study was obviously wrong. Why? Because there were 15,322 confirmed cases at the time. Multiply that number by 999 and you have over 15 million cases. The population of Sweden is just a little over 10 million people. Today officials corrected the record and said the actual multiplier was much lower:

The Public Health Agency’s deputy state epidemiologist Anders Wallensten noted when presenting the figures at the agency’s daily press conference at 2pm that it was a relatively large increase on the previous day. He said they were looking into why, but that “we are not seeing a downturn”…

Wallensten also corrected figures published in a report by the Public Health Agency on Tuesday, which was almost immediately retracted after a journalist noted incorrect figures in the presentation.

He said that the report had now been corrected, and that the main conclusion remained the same apart from minor changes: it now names April 8th, rather than April 15th, as the date when most people were contagious, and that 26 percent of Stockholmers are expected to have contracted the virus by May 1st.

The main error in the report, that there were around 1,000 times as many people infected by the coronavirus as the number of confirmed cases (1,000 times the number of confirmed cases in Sweden would amount to more than the country’s entire population), had happened when a wrong variable was added in when creating the model. The correct figure is an estimation of 75 cases per each confirmed case in Stockholm.

They had been previously saying that a third of Stockholm would have the virus by May 1, now that’s dropped to a quarter. The multiplier of 75, for the number of unseen cases, is a bit higher than the estimate from the LA County study. That study suggested there were 28 to 55 times the number of confirmed cases. But as I pointed out yesterday, there are some problems with that study and a similar one in Santa Clara County. In particular the death rates they estimate doesn’t seem to jibe with what we’re seeing in New York. Speaking of New York, there are some significant new antibody test numbers from the state today. Allahpundit has a post on that coming up shortly.