On Wednesday, China reported far fewer cases of the novel coronavirus than it did the day before, signaling that the spread of the virus could be slowing.
But the numbers were back up yesterday with China announcing a major jump in both new deaths and new cases.
There are many reasons we’re seeing this phenomenon, including variances in the incubation period and more people seeking treatment.
But one of the top reasons for the variation in numbers is the constantly changing definitions of what constitutes a case in China: Is it just when someone has a lab-confirmed test? Is it when they exhibit symptoms indicative of infection? Should someone who is asymptotic be counted?
The spike is partly due to a broader definition of what constitutes a confirmed case, to include people diagnosed on the basis of their symptoms rather than testing positive.
Keep in mind: This is normal.
“It’s normal during the course of an outbreak to adapt the case definition,” Dr. Sylvie Briand, director of the World Health Organization’s Infectious Hazards Management Department, said during a news conference yesterday.
Here’s a look at reported cases, according to World Health Organization data. Remember: These totals may differ from those reported by Chinese health officials, who report updated totals at different times than the WHO.