World health officials expressed "great concern" Wednesday that a dangerous new virus is starting to spread between people outside of China, a troubling development as China and the world frantically work to contain the outbreak. For a second day, the number of infections grew dramatically, the AP reports. The new virus has now infected more people in China than were sickened there during the 2002-2003 SARS outbreak. On Wednesday, the number of cases jumped to 5,974, surpassing the 5,327 people diagnosed with SARS. The death toll, which stood at 132 Wednesday, is still less than half the number who died in China from SARS, or severe acute respiratory syndrome. Scientists say many questions remain, including just how easily the virus spreads and how severe it is.
In a report published Wednesday, Chinese researchers suggested that person-to-person spread among close contacts occurred as early as mid-December. Based on the first 425 confirmed cases, the researchers estimate that each infection led to 2.2 others on average. That's a bit more than ordinary flu but far less than some other respiratory diseases such as whooping cough and tuberculosis. The rate for SARS, a cousin to this new virus, was estimated to be 3. "Considerable efforts" will be needed to control the spread if this ratio holds up elsewhere, researchers wrote in the report, published in the New England Journal of Medicine. Over half of the cases that began before Jan. 1 were tied to a seafood market, but only 8% of cases after that have been, researchers found.
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