The State must extend coronavirus testing to “wider population-based surveys to find out where the virus is” as part of a “control strategy” to be able to emerge from lockdown, the World Health Organisation’s special envoy on Covid-19 said.

Speaking to a Dublin foreign policy think tank, WHO envoy Dr David Nabarro said the Government’s challenge was to move from a “full lockdown” to being “Covid ready” to be able to deal with new outbreaks of the deadly disease as they emerge.

“Don’t imagine that you just come out of lockdown to business as usual when you pass the peak of your epidemic curve,” Dr Nabarro told the Institute of International and European Affairs in a seminar hosted online.

Testing a larger sample of the population to understand the asymptomatic transmission of the disease was an important part of the “control strategy” to lift lockdowns, he said.

He hoped that people who are asked to participate in larger sample surveys would do so because of the importance of the location of the virus and what it was doing.“It is quite likely that we will find that there are people who have the disease who don’t have any symptoms of the disease.”

The doctor declined to say whether the State’s weekly target of 100,000 tests was sufficient, but the level of testing needed had be “appropriate to find out how the the virus is moving”.

“It has to be done using the combination of studies of people who have got symptoms and then wider population-based surveys to find out where the virus is,” he said.

“You want to get enough of a sample to tell you what is going on, and that is not usually a very large number provided the sample is carefully selected and you are rigorous about the sampling.”

Necessary

Everything he had read “about the intention of the Irish authorities” around the pandemic planning was “absolutely in line with what I personally believe to be necessary”.

He said it was “right” for there to be “dense ethnical questions” as the State assesses how people are getting sick and dying to assess how health services will cope as restrictions are relaxed.

“Inevitably there are going to be people who say ‘are the overall sacrifices that all of society has to make so great that they are perhaps out of context with the actual suffering that occurs?'” he said.

“It is right that these ethical debates that are occurring because they are so important.”