Covid-19 deaths in Wuhan seem far higher than the official count

ON MAY 26TH Joe Biden, America's president, ordered his intelligence officials to redouble their investigation into the origins of SARS-CoV-2, the virus that causes covid-19. The spooks will seek to establish whether the virus escaped from a laboratory or jumped from animals to humans, perhaps in a live-animal market in the Chinese city of Wuhan. Whatever the source, Wuhan will forever be remembered as the city where the covid-19 pandemic claimed its first lives. How many people really died there?

Start with the official counts. Chinese health statistics report that there have been 3,869 covid-19 deaths in the city of 11m people. One-third of those deaths were added on April 17th 2020, when officials updated reporting standards, in particular to capture deaths that occurred outside hospitals. No more covid-19 deaths have been reported since.

However, as The Economist has found in other countries, official tolls often fail to capture the full impact of the pandemic. That is because recording covid-19 deaths requires both comprehensive testing and highly accurate reporting. This was especially difficult at the onset of the pandemic and, not least, in an authoritarian system that does not easily own up to failings and can produce questionable statistics.

An article published by the British Medical Journal (BMJ) on February 24th offers some clues on the extent of the underreporting. The authors, affiliated with China’s Centre for Disease Control and Prevention, have access to all-cause mortality data from the country’s national disease-surveillance system and other, less detailed, sources. Using information from January 1st 2020 to March 31st 2020, they found that Wuhan registered 5,954 more deaths when compared with the same period in 2019. They also found that deaths from covid-19 and other pneumonia-like illnesses in the rest of Hubei province, where Wuhan is located, were higher than usual (although overall deaths in the province were not higher than in 2019). In the rest of China, meanwhile, mortality was at lower levels than a year earlier.

The authors did not respond to The Economist’s requests to share their data. However, a table in the article’s appendix allowed us to reconstruct some of their weekly figures for excess mortality and compare it with official covid-19 deaths. The data suggest that total excess deaths in Wuhan between January 1st 2020 and March 31st 2020 numbered 13,400. That is more than triple the official count, and more than double the estimate in the BMJ paper. There were no excess-death statistics for the period from April 2020 onwards.

Our figure is different for several reasons. First, our tally is extrapolated from Wuhan’s three “disease-surveillance-point districts”, covering about one-fifth of the city’s population, that report weekly figures. Our estimate therefore relies on the assumption that these areas are representative of other districts that did not report data. However, unlike the calculation in the BMJ paper, our estimate is based on a model that accounts for delays in reporting and relies solely on data from the national surveillance system, which were accessible to us and may be more reliable.

Whatever the true toll, it is certain to be larger than the official number of covid-19 deaths. If the tally is more than 10,000 it would mean Wuhan’s first wave was more severe than London’s, but less severe than that of New York City. If we were to adjust for demography and density in those cities, the first wave might look tragically similar. Per 100,000 people, excess deaths in Wuhan’s first wave appeared to be 121 (by our calculation) or 53 (according to the BMJ paper). This compares with 108 in London and 301 in New York (which is more densely populated and has a higher share of old people than Wuhan or London). The big difference, though, is that Wuhan has not recorded a second wave.

Editor's note: replication code for this article can be found on our GitHub repo.