The National Health Commission said in its daily report that 1,370 patients remained in critical conditions, and 12,167 people were suspected of being infected with the virus as of the end of Wednesday.
A total of 124 people had been discharged from hospital after recovery.
Wednesday saw 1,737 new confirmed cases, including the first confirmed case in Tibet Autonomous Region, 4,148 new suspected cases, and 38 deaths — 37 in Hubei Province and one in Sichuan Province.
Also on Wednesday, 131 patients became seriously ill, and 21 people were discharged from hospital after recovery.
A total of 88,693 close contacts had been traced, the commission said, adding that among them, 2,364 were discharged from medical observation on Wednesday, with 81,947 others still under medical observation.
The boy’s case, published Jan. 24 in the Lancet medical journal, was the first to demonstrate person-to-person and health-care associated spread of the newly identified virus, dubbed 2019-nCoV. The asymptomatic infection has fueled concern the pathogen, which has already spread to 15 countries and infected close to 6,000 people, may turn out to be harder to detect and contain than SARS, the similar pneumonia-like illness that erupted into a global epidemic.
The 10-year-old boy’s lungs were also scanned “on the insistence by the nervous parents” and showed signs of infection, which was confirmed by swabs of the back of his nose and throat. That meant he was capable of transmitting the virus even though the kind of tests used in airport screening for the virus would not identify him as a carrier.