The entire Chinese province of Jilin is under lockdown as COVID-19 cases surge across the country.

Jilin's daily case counts topped 4,067 on Monday alone, leaving health officials scrambling to catch up to the highly transmissible omicron variant.

China is combatting the highest level of COVID-19 cases ever, with more than 10,000 cases since it scattered across 27 provinces and municipalities since the start of this month.

China's tried and true method for keeping cases close to zero for more than two years has been to trace, test, and isolate all infections, their close contacts, and the close contacts of those contacts faster than the virus can spread.

In the latest surge, however, the highly transmissible omicron variant has moved more quickly than contact tracing allows.

The result has been a return to full lockdowns for Jilin's 24 million residents, who are now forbidden to leave as of Monday and are required to shelter at home. In Shanghai and Beijing, all schooling has been moved online indefinitely.

Langfang, in Beijing's northern Hebei province, as well as Shenzhen and Dongguan cities, in China's south, are also under lockdown as of Tuesday. Two other cities – Shanghai and Xi'an – have put in place some lockdown measures.

China has contained omicron outbreaks before, but none has grown as big as the current surge. The strain is already showing, as cities are running out of isolation facilities to put tens of thousands of close contacts.

Nearby, Hong Kong serves as a warning of the cost of failure. The city is still logging to more than 26,000 new cases in a day and suffers the world's highest COVID rate of fatality.