Authorities in China’s Hubei province reported a dramatic spike in coronavirus cases on Thursday: 14,840 new cases.
It was most reported in a single day since the outbreak began in December. The Hubei Health Commission also reported that an additional 242 people had died.
But the virus didn’t suddenly becoming more aggressive — instead, Hubei officials said they changed the way they count cases. Rather than relying only on blood tests, which are in limited supply and can take take days to yield results, officials have started including diagnoses made via CT scans in their daily case totals.
The scans are considered less thorough than a blood test, but the New York Times reported last week that doctors in Wuhan, where the virus originated, are running short on test kits.
Patients diagnosed via CT scan — what Chinese officials call “clinically diagnosed cases” — present symptoms of the virus in their lungs, but either haven’t been lab-tested or died before the test could be administered.
The latest figures suggest the virus has killed at least 1,370 people and infected more than 60,000 in total. That number is expected to rise significantly as CT scans capture more cases in the coming days.
Here’s what physicians look for in the scans.