The World Health Organization is closely watching other Chinese regions for signs that new infection hot spots are emerging as the deadly coronavirus outbreak spreads beyond the epicenter of Hubei.

The 10 provinces, which include Zhejiang, Guangdong and Henan, have seen numbers of cases slowly rise, WHO’s China Representative Gauden Galea said in an interview on Bloomberg TV Monday. “Those are the numbers to watch,” he said, adding that while the situation seemed under control it is too early to say the spread of the novel coronavirus has peaked.

The global health agency’s focus on more Chinese provinces highlights the escalating battle against a pathogen that has claimed more lives than SARS in 2003. It has so far killed more than 900 people and infected over 40,000, mostly in China. As China ostensibly returns to work this week after a Lunar New Year holiday that was extended due to the outbreak, infections are still growing by the thousands everyday.

There were a few days last week when the growth in both the number of new infected and suspected cases declined in Hubei and its capital Wuhan, Galea said. This could give “a much needed sigh of relief” to the region. “We are happier to see the numbers go down rather than up,” he said.

The declines in one region was accompanied by rise in number of infections in other provinces, despite an ongoing lock down of Hubei. The WHO Director-General Tedros Adhanom Ghebreyesus said in a tweet Sunday that “we may only be seeing the tip of the iceberg,” voicing concerns over the spread from people with no travel history to China.

“The best sign is when one sees numbers reach a peak and then decline, well beyond the incubation period. We are not in that stage yet,” Galea said. “It’s absolutely impossible to reach a conclusion at this stage that containment has worked,” he said, referring to the Jan. 23 decision by China to seal off Wuhan and surrounding cities to curb the outbreak.

Galea lauded the Chinese government’s “extraordinary approach” to contain the outbreak as soon as human-to-human transmission was detected.

Despite the WHO’s line, criticism has mounted over China’s transparency and speed in handling the epidemic, especially after the death of a doctor who was censured by authorities after becoming on early whistle-blower on the virus’ spread. This triggered widespread discontent at the Chinese government, stoking anger on social media.

Reports are emerging that signs of human-to-human transmission was seen by the start of January, although both Chinese officials and the WHO made early statements to the contrary.

WHO has also been criticized for being slow in not declaring the epidemic a “public health emergency of international concern” until Jan. 31, more than a month after the SARS-like illness was first reported in Wuhan, and after it had already traveled to the U.S.

Galea defended the WHO, saying the organization declared the public health emergency status when it saw the need to warn other countries to get their health systems ready.

While the WHO has been in constant contact with Chinese authorities on the virus, Galea said it was difficult to identify a chain of transmission in earliest cases of the virus jumping between humans.

“The possibility to human-to-human transmission was recognized from the beginning,” he said. “It was just the extent to which it could be demonstrated” that was harder to pin down.

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