The virus was first introduced into Hokkaido by tourists. Photo / File
A timely warning from the Japanese island of Hokkaido shows the dangers of lifting a Covid-19 lockdown too early - and why Kiwis are not out of the woods yet.
A northern region of Japan is experiencing a second wave of coronavirus infections - and deaths - that experts say could have been avoided if the state of emergency had not been lifted too early.
The island of Hokkaido had been held up as a model of how to control the spread of the virus, but it has now become a case study for the impact the disease can have if a lockdown is relaxed too soon.
And experts say they hope that other cities and nations that are toying with the idea of lifting restrictions on travel, work and schools can learn from Hokkaido's experience.
Naomichi Suzuki, the prefectural governor, on February 29 declared a state of emergency in response to a sharp increase in coronavirus cases, all of which could be traced back to the Sapporo Snow Festival at the beginning of the month.
The annual event attracted more than two million people to the city, with local health authorities treating a Chinese tourist from Wuhan who had contracted the illness before arriving in Hokkaido.
Despite the state of emergency, 118 people were being treated for the virus by March 12, making Hokkaido the worst-hit of all Japan's 47 prefectures.
In tandem with the state of emergency - under which schools were closed, large-scale gatherings were cancelled and people were officially "encouraged" to stay at home - the local government introduced aggressive measures to trace and isolate anyone who had been in contact with victims.
The approach appeared to have been effective and, just a week later, the number of new cases had fallen to one or two a day.
Assuming that they had weathered the storm - and keen to get the local economy operating again - local authorities lifted the state of emergency on March 19, with schools and businesses reopening.
With hindsight, experts agree, it was too early and, just 26 days later and after 135 new infections were reported in the space of a week, the lockdown was reimposed on Hokkaido's 5.3 million residents.
"At the time, we didn't have enough information and we did not have an adequate understanding of this disease", said Yoko Tsukamoto, a professor of infection control at the Health Sciences University of Hokkaido.
"And, given the information that was available - that new cases were down to one or two a day - it could be argued that the governor made the right decision in lifting the state of emergency," she told the Telegraph.
"We know that was the wrong move now, but then it seemed the best thing to do".
The lessons that other authorities will have to learn if they want to protect their residents are clear, Tsukamoto said.
"These lockdowns and states of emergency will have to be lifted eventually, but the lesson is to wait as long as possible, to get accurate data on infection numbers and to be very, very cautious when the rules are relaxed.
"And the authorities have to be ready to move quickly and put the restrictions back in place at the first sign of another surge."
The Japanese government plans to extend the state of emergency over the new coronavirus pandemic by about one month for the entire country, the Nikkei business daily reported on Wednesday.
The state of emergency is currently scheduled to end on May 6.
Thirty-eight new cases were reported across Hokkaido on Tuesday, bringing the total number of infections to 688, the fifth-highest in Japan. The illness also claimed one more life, raising the death toll to 27.
In a nation of 127 million people, there have been 13,576 cases and 376 deaths to date, although the government has been criticised for limiting the number of tests that are conducted on suspected coronavirus patients and the true figure is likely to be significantly higher.