China’s health authorities have decided to no longer count as confirmed cases those patients who test positive but don’t show symptoms. Skepticism was immediate. The news was abrupt and, to some, surprising: Overnight, Heilongjiang, a Chinese province near Russia, had cut its count of confirmed coronavirus cases by more than a dozen.The revision stemmed from what appeared to be a bureaucratic decision, buried in a series of dense documents from the national government. Health officials said that they would reclassify patients who had tested positive for the new coronavirus but did not have symptoms, and take them out of the...