Image copyright AFP Image caption Some Asian countries have useful lessons for the West - as well as a preview of what challenges could follow

The number of coronavirus cases in the West is skyrocketing, and countries have announced drastic measures, including school closures and lockdowns.

The outbreak hit many countries in Asia several weeks earlier - and some places have been praised for containing the number of infections. For example, Singapore, Hong Kong and Taiwan all kept case numbers relatively low - despite their proximity to mainland China.

What did they do differently - and are there any lessons for other countries?

Lesson one: Take it seriously - and act quickly

Health experts agree on the same measures for containing the outbreak - test widely, isolate those infected, and encourage social distancing. Such measures are being adopted to varying degrees in the West now - but a key difference is that many countries didn't act as quickly.

"The UK and US lost an opportunity," says Tikki Pangestu, a former director of research policy at the World Health Organization (WHO). "They had two months from what happened in China, yet there was this perception that 'China is very far away and nothing's going to happen'."

Media playback is unsupported on your device Media caption A doctor who became a patient describes what it's like to get tested for coronavirus

China first reported cases of "mysterious Sars-like pneumonia" to the WHO on 31 December. At this point there was no confirmed human-to-human transmission, and little was known about the virus, but within three days Singapore, Taiwan and Hong Kong had all stepped up screening at border points - Taiwan even checked passengers on flights from Wuhan before they got off the plane.

As scientists learned more about the virus, it became apparent that people without symptoms could still be contagious. So testing would be crucial.

Lesson two: Make tests extensive, and affordable

Media playback is unsupported on your device Media caption 60 days of coronavirus in the US - in 60 seconds

Cases in South Korea spiked initially. However, it swiftly developed a test for the virus - and has now tested more than 290,000 people. It conducts about 10,000 tests daily for free.

"The way they stepped up and screened the population was really remarkable," says Ooi Eng Eong, a professor in emerging infectious diseases at the National University of Singapore.

South Korea had a rapid approvals system in place for infectious disease tests, following an outbreak of Middle East Respiratory syndrome in 2015 that left 35 dead.

By contrast, testing in the US was delayed - initial test kits were faulty, and private laboratories found it hard to get their tests approved. Many people struggled to get a test, and they were expensive. Eventually, free testing for everyone was passed in law.

Meanwhile, the UK has said that only those in hospital will be routinely tested. That makes it harder to identify cases with milder symptoms.

Prof Pangestu recognises that in some countries there aren't enough test kits. However, he describes extensive testing as "the most important priority", adding that "testing those who are symptomatic but not necessarily hospitalised and still spreading the virus is perhaps even more important".

Lesson three: Trace and isolate

It's not enough to just test those with symptoms - tracing those with whom they were in contact has been key.

In Singapore, detectives have contact-traced more than 6,000 people - locating individuals with CCTV footage, testing them, and ordering them to self-isolate until their results are clear. In Hong Kong, contact tracing goes back to two days before someone develops symptoms.

They have also adopted intrusive ways of ensuring that those ordered to self-isolate actually stay at home. In Hong Kong, new arrivals from abroad are required to wear electronic bracelets to track their movements, while in Singapore those self-isolating are contacted several times a day, and required to send photographic proof of their whereabouts.

Image copyright Reuters Image caption Singapore has even deployed the armed forces in contact-tracing

Singapore has hefty penalties - including jail terms - for anyone who breaks a "stay at home" order. It stripped one offender of his residency rights.

Many countries in the West will find it hard to adopt such measures due to their larger populations, and greater civil liberties.

"We can do what we did because we're small," says Prof Ooi. "To replicate what we're doing in its entirety would not make sense, it has to be adapted to suit each country."

Lesson four: Early social distancing

Social distancing is considered one of the best ways of containing an outbreak.

Image copyright AFP Image caption In Hong Kong, many busy streets fell quiet

But the later the measures are introduced, the more extreme they need to be to work. In Wuhan, China, where the virus is thought to have started, five million people had left the city before the shutdown began. This led to the government imposing the biggest quarantine in human history.

Both Italy and Spain were forced to introduce national lockdowns after their case numbers rose to the thousands. New York and California have ordered residents to stay at home, except for essential trips like buying groceries.

By contrast, schools are still running in Singapore, although large public gatherings have been cancelled. In Hong Kong, schools have been closed and workers encouraged to work from home - but restaurants and bars remain open.

Prof Ooi believes the difference is down to how quick governments were to implement social distancing.

"By the time a lot of countries had stepped up control measures, the number of cases was so large" that drastic steps were needed, he says.

Social distancing is affected by government decisions to ban gatherings or close schools, but it also depends on people being willing to take part. That's why public messaging - and individual attitudes - matter.

Lesson five: Keep the public well informed and on side

"Unless you get the co-operation of the public, your policies may not be adhered to, and enforcement only goes so far," says Prof Pangestu. "The important thing is to show that policies are based on scientific evidence."

China came under fire for being slow to acknowledge the outbreak. It allowed a large political gathering to take place in Wuhan even as concerns grew. The authorities also punished doctors who tried to warn others - sparking fury after one died from the virus.

Image copyright Reuters Image caption The outbreak has led to people stocking up on food supplies

It has since been praised for effectively slowing the spread of the virus, after imposing a massive lockdown and upscaling its hospital capacity. But critics say such extreme measures were only required because its initial response was slow.

In the US, President Donald Trump has often contradicted health officials about the severity of the outbreak and the number of test kits available. The government has also been unable to provide information on the number of people who have been tested, as many private laboratories have not been feeding data to the CDC.

"Outbreak response involves being transparent - that stops people panicking and hoarding things," says Prof Ooi.

Some governments have used technology to update residents in great detail. Hong Kong provides an online dashboard of all cases - which includes a map that shows the individual buildings where cases were found. South Korea issues mobile alerts letting people know if they were in the vicinity of a patient.

In Singapore, the government has been praised for its clear communications on coronavirus, including a speech by the prime minister which encouraged people to stop panic buying. Its measures have had widespread public support - helped by the fact Singapore has a long history of emphasising collective responsibility for national security. And Singaporean media does not tend to challenge the official line.

Lesson six: It's also down to individual attitudes

It's far too simplistic to say, as some have, that Asians are more likely to comply with government orders. In Hong Kong, public trust in the government is low - and there have been months of anti-government protests. But, in one of the densest cities in the world, many have voluntarily socially distanced themselves - with some even avoiding Lunar New Year gatherings, the equivalent of skipping Christmas events.

Prof Pangestu believes that while Hong Kongers do not trust the government, "they are very proud of Hong Kong, and see the outbreak as a threat to [the territory's] identity".

Image copyright AFP Image caption One survey suggests 98% of people in Hong Kong wore facemasks in public due to the outbreak

Meanwhile, Karin Huster, a Seattle-based nurse and emergency field co-ordinator for Doctors Without Borders, spent a month in Hong Kong working on coronavirus training. She noticed many there had a strong "individual sense of responsibility" because they remembered the 2003 Sars outbreak that hit the territory particularly hard.

That's also seen in the prevalent use of masks in part of Asia, which Ms Huster says is seen as a sign of "respect towards others".

She noticed that occasionally people would avoid getting into a lift with her because she was not wearing a mask. By contrast, in much of the West, people have specifically been told not to wear masks unless they are ill, and many Asians have experienced harassment while wearing one.

Experts in Asia agree that masks are far less effective than measures like hand washing, and that where supplies are limited, they should be left for healthcare workers. But there are different opinions over whether wearing a mask is worthwhile.

Benjamin Cowling, an epidemiology professor at the University of Hong Kong, argues: "Masks are not a magic bullet against coronavirus… but if everybody wears face masks, it probably can help, along with all the other measures [like hand washing and social distancing], to reduce transmission.

"The evidence base is quite thin, but we presume they have some effect, because that's the protection we give to healthcare workers."

Media playback is unsupported on your device Media caption US students on spring break defy COVID-19 warnings

When it comes to social distancing, Ms Huster says: "I think in America, people are so individualistic - it's going to be a little harder for us to sacrifice our 'freedom'."

She previously worked on the Ebola outbreak, where people were also required to wash hands more frequently and socially distance, and says the biggest challenge "was making people understand the need to change the way they were doing things".

Is all this enough to stop the virus?

Experts believe the more aggressive measures being put in place in Western countries will successfully slow the rate of transmissions over time. But, to get a sense of their next challenge after that, they could also look ahead to Asia. Despite having contained the virus, China, South Korea, Taiwan, Singapore and Hong Kong are now facing a second coronavirus wave, fuelled by people entering their borders.

And it's not clear how long this outbreak could go on for.

Prof Ooi is optimistic, as new infection numbers started falling within two to three weeks of lockdown in Hubei province. While China's shutdown was "drastic", he believes countries with softer measures should also be able to contain the outbreak within weeks.

"It should serve as inspiration for other countries right now - it's painful but it can be done."

By contrast, Prof Cowling worries that if a lockdown ends too early, local transmissions could start again.

"I don't know if social distancing can be sustained for the kind of time they need to be sustained. We can't really relax until there's a vaccine - which could take about 18 months," but "people in Hong Kong are already a bit tired after two months."

"Prolonged lockdowns are damaging for the economy, while an epidemic is damaging to public health… there's not a lot of good choices."