(Bloomberg) -- China’s lockdown of Wuhan and its surrounding areas to contain the coronavirus represents the first large-scale quarantine in modern times.

The effectiveness of attempting to cordon off the epicenter of the disease -- an area of roughly 40 million people -- will probably be scrutinized far into the future.

“The containment of a city hasn’t been done in the history of international public health policy,” said Shigeru Omi, who headed the World Health Organization’s Western Pacific Region during the SARS outbreak in the early 2000s. “It’s a balance between respecting freedom of movement of people, and also prevention of further disease and public interest. It’s not a simple sort of thing; it’s very complex.”

Aside from raising questions about its probable effectiveness and implications for human rights, a quarantine could cause panic, public health experts said. The government will also have to ensure supplies of food, water and medical materials.

Some argue the authorities may have had no choice, since certain patients appear to have milder symptoms that can go undetected, allowing them to unwittingly spread the disease. Saturday also marks the start of the Lunar New Year holiday, when more than 500 million trips by plane and rail may be taken within and out of China.

Restricting the movement of those who may be carriers of diseases is an approach that goes as far back as the 14th century, though historically it was used mainly in smaller cities or neighborhoods. In China, the city of Wuhan alone -- where the first outbound travel restriction was announced -- has a population greater than any U.S. city at 11 million.

Chinese authorities first suspended all plane and train travel out of Wuhan early Thursday. The restrictions were later extended to other nearby cities.

“It’s a tremendous legal, institutional, not to mention logistical challenge, but it’s an authoritarian state with a top leader who happens to have centralized power,” said Yanzhong Huang, director of the Center for Global Health Studies at Seton Hall University.

In modern times, quarantines have yielded limited results. A study in the Canadian Journal of Infectious Diseases and Medical Microbiology determined Toronto’s use of quarantine wasn’t effective in slowing SARS. An impoverished neighborhood in Liberia quarantined during an Ebola outbreak in 2014 responded with violent riots.

China has been trying to prove it has the wherewithal to respond to public health crises since its handling of the SARS outbreak in 2002 and 2003 was widely criticized, with authorities accused of delaying information disclosure and attempting to downplay the seriousness of the disease. This has at times led to the trigger being pulled too fast. In 2014, parts of the northwestern city of Yumen were quarantined after a man died of the bubonic plague, causing public alarm. No other cases were reported.

The current lockdown has also taken its toll. Yaqiu Wang, a researcher for Human Rights Watch who has been tweeting about the impact, cited a case on Chinese social media where a Wuhan couple said they had a fever and didn’t want to infect their children, but no relatives were able to come help because of the travel shutdown.

Limiting Contact

One measure that does work is social distancing, or intervention to limit human-to-human contact, Omi said, citing the example of Philadelphia and St. Louis during the 1918 influenza epidemic. That would include measures like shutting down schools and public gathering spaces. In China, the government has called off all Lunar New Year celebrations, and companies have closed off areas like theme parks and movie theaters.

The nature of epidemics makes it ultimately difficult to measure the success of quarantines, according to Yvonne Maldonado, an epidemiologist at Stanford University School of Medicine. Even if the virus stops spreading, it will be hard to identify the golden bullet, she said. Sometimes the organism itself changes, or vaccines and medications are developed, which can all stop the spread.

“You’re never going to know the answer right now and never know the full answer,” Maldonado said.

--With assistance from Iain Marlow.

To contact the reporter on this story: Lisa Du in Tokyo at ldu31@bloomberg.net

To contact the editors responsible for this story: Rachel Chang at wchang98@bloomberg.net, Anne Pollak, John Lauerman

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