TOKYO (BLOOMBERG) - The virus might have been new, but for Yuko Koizumi, the work was still the same.
In Kawasaki, a city just south of Tokyo, nearly 300 people had tested positive for the coronavirus by early June. But Koizumi was unperturbed. As head of infectious disease response for the city's network of seven public health centres, she was able to draw on a familiar strategy used in past pandemics and seasonal outbreaks: trace infection routes via close contacts, check on recuperating patients, and arrange treatment where needed.
It's a playbook that may have made all the difference in Japan's unorthodox, though largely successful, virus response.
Kawasaki's seven public health centres are part of a web of over 450 such institutions across Japan which played a crucial role in limiting the nation's outbreak. The centres meant Japan already had an army of trained contact tracers when the virus struck, and may provide a model for other countries as they look to build systems that will future-proof them for the next pandemic.
Experts contend that the existence of these centres, which implement and execute central public health policy from giving the elderly diet advice to investigating child abuse, are one of the key reasons Japan was able to avoid an explosion in coronavirus cases.
"I don't think I would have been able to do it if it wasn't something I already knew how to handle," Koizumi said. "We also already had a team of people that could communicate and work together."
Centre staff played a crucial role in quick contact tracing, serving as early gatekeepers when the first cases of the disease in Japan were identified in January. They asked people infected with the virus to detail their movements, share personal information and disclose the details of people they had met to trace who needed to be tested and isolated.
While largely unknown outside of the medical community prior to the Covid-19 pandemic, trained contact tracers are now recognised to be the cornerstone of a successful virus response, used effectively in nations from South Korea to Germany.
A cluster of eight cases had appeared in a local hospital in Kawasaki when Bloomberg News spoke with Koizumi earlier this month.
"It's already under control," she said, four days after the cluster was reported. "The day after cases emerged, the local centre sent staff to the hospital to figure out close contacts and advise on how to disinfect the necessary areas."
Unlike in some Asian cities such as Hong Kong, where the authorities have published detailed accounts of the workplaces, residences and restaurants and bars visited by infected people to get others to come forward for testing, officials in Japan have studiously avoided publicly identifying businesses or even regions hit.
With privacy paramount, public health centre workers have been able to conduct tracing while maintaining the anonymity of their patients.
"People trust the public health centre and will share any kind of information with them," said Haruka Sakamoto, a public health researcher at the University of Tokyo. "They understand the characteristics of the community."
The public health centres perform a myriad of functions in local neighbourhoods, serving as a communal glue of sorts. In addition to infectious disease response, they oversee a wide range of health concerns, from advising the elderly on diet and exercise and conducting health check-ups on newborns, to issuing licences for bars and restaurants and investigating cases of child abuse or food poisoning.
That in-built connection to the community helped with the initial coronavirus response, which involved tracking the disease and informing citizens of the right precautions to take. Even now, the work of contact tracing, arranging tests, and identifying clusters is still being done across the centres as the country continues to reopen.
At the Chitose public health centre in Hokkaido, workers are now fielding around 30 to 40 calls a day, down from more than 100 at the peak in early May, said Reiko Kano, a public health nurse at the centre with over two decades of experience.
"Trust is very important, especially if you're suddenly just getting a call from someone," said Kano. "You have to think about your final goal, and be very careful about protecting privacy and personal information while also realising there are certain things you have to ask. There's a balance you need to strike."
Japan's public health centres trace their roots back to a programme in the 1930s to fight tuberculosis, a disease that, like Covid-19, requires a trace-and-track response, said Toshio Takatorige, a public health professor at Kansai University in Osaka. In contrast, public health systems in Western nations stem from an earlier fight against cholera in the 19th century, he said - a very different type of pandemic that can be solved by improving water and sewage systems.
"The tuberculosis problem was more serious than the coronavirus is now," Takatorige said. It was also a serious issue for the Imperial Army, ensuring a well-funded response. To this day, containing TB remains one of the public health centres' core functions, with Japan having one of the higher rates among OECD nations.
Similarly, experience with past epidemics - Hong Kong's bruising encounter with Sars in 2003, South Korea's 2015 struggle with Mers - has helped other Asian countries also weather the pandemic better than Western nations.
"For tuberculosis, you need to follow up for two years - the coronavirus tracing time period isn't as long," Takatorige said. "The public health centres carry out the tuberculosis strategy on a daily basis, so comparatively the coronavirus response is easy."
Public health centres have also provided data that was integral to Japan's understanding of the virus, Hitoshi Oshitani, a professor of infectious diseases at Tohoku University and member of a panel of experts advising the Japanese government on its virus response, said at a press conference on June 1.
The centres themselves are far from flashy or high-tech. Contact tracing breaks down when there are too many cases at once, as happened in Japan in April. The centres lack a centralised system to share information and use faxes to report individual infections, slowing the transmission of vital information and adding to an already heavy workload.
Funding for the public health centre system has also dwindled in recent years, causing the number of centres to fall by nearly half in the last 30 years, according to a professional group for public health centre directors in Japan. This has overloaded denser cities in particular, which have also been worst hit by the coronavirus.
But the centres may now be cherished anew, as other nations struggle to assemble contract-tracing operations amid the pandemic.
"Things like how to ask questions, it's all on-the-job training," said Nobuhiko Okabe, the director general of Kawasaki City's Institute for Public Health who is also a member of the government's expert panel. "You need people who are used to it. It's not something you can do just by increasing the number of people."
A 41-year-old man who contracted the coronavirus in Tokyo in April told Bloomberg News that staff from the local public health centre called him without fail every day while self-isolating at home - asking him to describe his conditions, and providing advice on when was appropriate for him to leave the house after his symptoms subsided. The man, who declined to be identified for privacy reasons, was also asked to log his temperature and condition on a website daily, as well as questioned over who he may have been in close contact with.
"Everyone is captivated by potential treatments and vaccines, because if they're successful there will be money for pharmaceutical companies," said Takatorige, the public health professor in Osaka. "No one thinks about the system that's already a part of daily life."