COPENHAGEN (BLOOMBERG, AFP, NYTIMES) - Some countries have ramped up their coronavirus testing, even on those who display mild symptoms, in a bid to halt the virus' spread.

Denmark Health Minister Magnus Heunicke said on Monday (April 20) that anyone displaying mild symptoms should contact their doctor by telephone.

If told to do so, they would be able to undergo testing in the new facilities, which include makeshift labs in white tents being set up across the country.

The country previously tested only people with severe symptoms, or those with mild symptoms and close ties to the elderly or patients suffering from chronic diseases.

In Australia, the authorities have advised those who have a cough, temperature or a sore throat to get tested for coronavirus, as part of the country's widened criteria to weed out anyone with symptoms.

The government is also pushing ahead with plans to introduce a non-compulsory coronavirus tracing app, touted as a key to improving contact tracing by detecting whether people had spent more than 15 minutes with others who may have been infected.

The expanded testings come on the back of praises for some nations that have acted quickly to test their people as the virus spread.

Iceland, with just 364,000 people, has tested about 10 per cent of its population. That makes it by far the world leader in testing per capita - 10 times more than South Korea.

South Korea has conducted 10 tests per 1,000 inhabitants, according to the website Our World in Data.

Iceland launched an all-out screening programme on Jan 31 - before the disease caused by the virus had been named Covid-19 and more than a month before the global pandemic was declared.

The first phase of the programme targeted people with symptoms of coronavirus infection and people who had travelled to high-risk areas - initially China and the Alps regions of Austria, Italy and Switzerland - or people who had come into contact with others who were in fact infected with the virus.

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A second phase that began March 13 screened the general population of people with no coronavirus symptoms or who had mild symptoms, such as those of the common cold, and were not in quarantine.

Both phases allowed health authorities to detect people who were infected and contagious but had no symptoms or thought they just had a cold or the flu.

When people were told they had tested positive, they had to self-isolate at home until 10 days after their fever subsided or until they tested negative for the virus. And anybody who came in contact with them had to self-quarantine for two weeks.

South Korea has gained gained plaudits for its mass testing but the rapid response comes from its experience in tackling another outbreak five years ago.

Back then, the Middle East respiratory syndrome (Mers) killed 38 people in South Korea due to lack of testing kits, which means infected patients went from hospital to hospital seeking help, spreading the virus widely.

Following that experience, the country created a system to allow rapid approval of testing kits for viruses which have the potential to cause pandemics.

When Covid-19 emerged, that system allowed regulators to collaborate quickly with local biotech companies and researchers to develop testing kits based on a genetic sequence of the coronavirus released by China in mid-January. Firms were then granted accreditation to make and sell the kits within weeks - a process that usually takes a year.

As a result, South Korea has managed to test more than 140,000 people for the novel coronavirus in a short space of time, using kits with sensitivity rates of over 95 per cent, according to the director of the Korean Society for Laboratory Medicine.

The tests are largely free and for the elderly or those too ill to step out, medics visit their homes to take swabs for testing.

South Korea also made headlines around the world for its drive-through screening centres and ability to test thousands of people daily.

The emphasis on diagnosis is also being credited with helping patients get treatment early, bringing the mortality rate from the virus to under 1 per cent.

In Germany, the country is planning to test its population for antibodies in coming months, hoping to gain valuable insight into how deeply the virus has penetrated the society at large, how deadly it really is, and whether immunity might be developing.

The country, which produces most of its own high-quality test kits, is already testing people for coronavirus symptoms on a greater scale than most - 120,000 a day and growing in a nation of 83 million.

The country had already tested about 920,000 people through late March and checked more than 350,000 people in the past week alone, the Robert Koch Institute public health group said in a report in early April.

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Germany's comprehensive testing and relative progress in protecting vulnerable people have led to a lower fatality rate than European partners such as Italy, Spain and Britain.

Still, global constraints in the supply of reagents used in testing for the coronavirus has affected testing abilities of countries like Indonesia and Britain.

Mr Achmad Yurianto, Indonesia's spokesman for Covid-19 matters said the Health Ministry was scrambling to procure reagents from other countries, as Indonesia's stock would only last a week. The supply, he was quoted as saying by The Jakarta Post, would only be enough for 35,000 tests.

The government estimates 1.2 million tests are needed by the end of May - a conservative figure.

In the UK, Cabinet Office Minister Michael Gove has said late last month that the government has said the difficulty in increasing the number of Covid-19 tests is due to a shortage of the relevant "chemical reagents".

Meanwhile, in the US, a shortage of test kits and technical flaws significantly delayed more widespread testing of the virus, health experts had said, letting it spread undetected for weeks.

An average of 147,000 people per day have been tested for the coronavirus nationally so far this month, according to the Covid Tracking Project, which as of Monday reported just over four million total tests across the country.