By Reuters staff
GENEVA (Reuters) – The increase in cases reported from China reflects the reclassification of an accumulation of suspicious cases using patient chest images and not necessarily the "tip of an iceberg" of a larger epidemic, a senior official said Thursday of the World Health Organization.
Mike Ryan, head of the WHO health emergency program, said the increase of about 14,000 cases reported overnight by China reflected a change in approach to enumerating patients in Hubei Province whose infections were confirmed by chest images, not only those with laboratory confirmed results.
"Crucially we understand that most of these cases are related to a period that goes back to days and weeks and are retrospectively reported as cases, sometimes until the beginning of the outbreak," he said at a press conference at the WHO headquarters.
"We have seen this increase in the number of cases reported in China, but this does not represent a significant change in the trajectory of the outbreak," he said.
In addition, China has reported a total of 46,550 laboratory-confirmed cases since the outbreak began in December, according to WHO figures.
No significant changes in mortality or severity patterns were detected, Ryan said.
Conducting studies at home and developing serological tests that determine the level of antibodies in a community against a virus would deepen understanding of the extent of the epidemic, he said.
"But this idea that this iceberg is absolutely massive and somehow we are only detecting 1 or 2 or 5 percent, all this is based on modeling. This is based on certain assumptions," he said. "And those assumptions and speculations are as valid as speculations in the other direction."
Cases are not increasing dramatically outside of China, apart from passengers on a cruise ship that is now in quarantine off the Japanese port of Yokohama, Ryan said.
"External cases on the Diamond Princess cruise are not seeing dramatic increases in transmission outside of China."
Another 44 cases were reported on the ship on Thursday, which raised the total to 219, although authorities said some older people would eventually be allowed to disembark on Friday.
Ryan said members of a WHO-led mission were expected to begin arriving in China next weekend, joining an advanced team led by Dr. Bruce Aylward who is already in Beijing to help investigate the outbreak. .
"In terms of the international mission, the advanced team and their Chinese counterparts have finalized the scope of the work and the design of the mission," he said, and refused to give details.