Social distancing and good hygiene aren’t enough to slow the coronavirus, the World Health Organisation has warned, as it urged countries to ramp up testing which remained the number one priority.

While individuals play a key role in thwarting the spread – such as by washing hands and avoiding contact with others – WHO’s director-general says nations need to invest in strategies to track down people who’ve had contact with patients.

“We have not seen an urgent enough escalation in testing, isolation and contact tracing, which is the backbone of the response” to determine who is sick, WHO director-general Tedros Adhanom Ghebreyesus said at a press conference on Tuesday morning (Australian time).

“You cannot fight a fire blindfolded and we cannot stop this pandemic if we don’t know who is infected.

“We have a simple message for all countries: test, test, test.”

• Related: Drive-through coronavirus testing facilities are coming to Australia

His comments come as UK Prime Minister Boris Johnson urged the public to stop travelling and steer clear of pubs, clubs and theatres.

The UK had about 5000 ventilators but would need “many times more than that”, Health Secretary Matt Hancock told Sky News.

Mr Johnson further warned that “without drastic action, cases could double every five to six days”. He said employees should start working from home.

Like the UK, which Mr Johnson said was “now approaching the fast growth part of the upward curve” in coronavirus cases, Spain has moved to shut down its land borders to “slow down the curve of infected people” after it became the country with the fourth-highest number of infected patients, surpassing South Korea.

Prime Minister Boris Johnson gives a press conference on the ongoing situation with the coronavirus pandemic. Photo: Getty

Only China, Italy and Iran have more confirmed cases of COVID-19 than Spain, where the number of infections increased overnight by roughly 20 per cent to 9191.

Germany, which saw its infections increase by over 1000 in 24 hours, restricted border crossings with France, Austria, Switzerland, Denmark and Luxembourg, while insisting the flow of goods wouldn’t be affected.

• Read coronavirus travel advice: From cancelled flights to self-isolation

Among the most drastic measures, the Swiss city-state of Geneva banned gatherings of more than five people, though exceptions were made for business meetings that followed public health rules.

In the US, health officials recommended a limit to groups of 50 or more people and a government expert said a 14-day national shutdown may be needed.

European Commission President Ursula von der Leyen suggested putting in place a 30-day ban on people entering the EU for non-essential travel.

Australian universities move to online teaching

In response to the rapidly changing #COVID19 situation, we are introducing a number of new measures—effective immediately—to both protect our community and continue our core activities of teaching, learning and research: https://t.co/thz4lqSbF4 pic.twitter.com/tusZEz56UH

— La Trobe University (@latrobe) March 16, 2020

From Tuesday, classes at three of Victoria’s largest universities, La Trobe, Monash and Swinburne, will be suspended until the end of the week so staff can prepare for online learning.

Swinburne University will pause lectures until next week, while those at La Trobe and Monash will be recorded and made available online.

In a statement posted online, La Trobe said the outbreak of COVID-19 is posing “unprecedented challenges” for the university.

“Events over the weekend and this morning have necessitated a rapid review of the university’s response,” it said.

If forced to close its campuses, La Trobe said all fixed-term and continuing staff would be paid, while casual staff would be paid for up to four weeks, based on the work they would have performed if not for the shutdown.

It comes after Premier Daniel Andrews declared a state of emergency along with multiple other states on Monday to enforce the national 14-day isolation sanctions on all travellers coming into Australia, earlier announced by the prime minister.

Schools have not been told to close but many private schools across the state – including Ballarat Grammar, Carey Baptist Grammar School, Loreto Mandeville Hall, St Kevins and Yeshiva-Beth Rivkah College – have decided to.

Coronavirus cases across the nation have reached more than 360 while five people have died.

Anzac Day services and marches have been cancelled in NSW, Western Australia and Tasmania with other states reviewing their commemorations.

Arts Minister Paul Fletcher will hold a teleconference with representatives of the creative sector on Tuesday, as museums, galleries and outdoor events such as concerts are banned.

-with AAP