China has quarantined 20 million to contain the coronavirus – but it could be too late

The announcement of public transport shutdowns in three Chinese cities to quarantine nearly 20 million people underscores the seriousness with which the Chinese authorities are taking the novel coronavirus outbreak.

Quarantine of infectious diseases has been used for hundreds of years. From my office window in Liverpool, I can see the spot on the River Mersey where, 200 years ago, ships were kept for 40 days to ensure they would not bring deadly plague, cholera or yellow fever into the city.

And a few hundred miles from here in Derbyshire is the famous Eyam village, which in 1665 quarantined itself to prevent the spread of the plague

In recent years quarantine has been used less, partly because of the impact on civil liberties.

Quarantine is governed by the application of the five Siracusa Principles which ensure that there are no alternatives. Restriction should be carried out in accordance with the law; should be in the interest of a legitimate objective; be strictly necessary; be based on scientific evidence; and should be a last resort.

Recent quarantines occurred in Canada and China during the Sars coronavirus outbreak in 2003, a plague outbreak in China in 2014, and the 2014-15 Ebola outbreak in West Africa.

During this epidemic, the containment measures often just applied to houses or small communities, but at one point, the entire area of West Point in Liberia - a township in the capital - was locked down.

Here, razor wires were used to enclose public spaces and restrict population movement. This was met with resistance and erupted into violence. The military fired on protesting crowds, killing one teenager and wounding at least one other.

Whether the quarantine in China will be effective remains to be seen. It has never been attempted before on such a large scale.

And containing a population equivalent in size to the cities of New York and London may prove to be an impossible task.

So far the closure of airports, railways and bus terminals seems to be working. And it may even be possible to police the main highways. But how do you stop people using smaller roads? An enormous military and police effort would be needed.

Ultimately the Chinese quarantine may be more about showing how seriously the authorities are taking the problem and demonstrating they are doing everything they can.

Already the disease has spread to many other Chinese provinces, and there are estimated to be thousands of undiagnosed cases across the country. Several other Asian countries are now affected, and the virus has also spread to the United States.

In the past, quarantining ships that took many months to traverse the oceans may have been effective for plague. But in this era of international travel, when it takes less than 24 hours to circumnavigate the globe, this quarantine in China may well be too late.

• Professor Tom Solomon is Director of the NIHR Health Protection Research Unit in Emerging Infections at the University of Liverpool. He tweets @RunningMadProf

Protect yourself and your family by learning more about Global Health Security. And sign up to our weekly newsletter here.