Certain countries have set themselves up for “blind driving” in their approach to lifting coronavirus lockdown measures, a World Health Organisation director has said.

Michael Ryan, executive director of the WHO Health Emergencies Programme, warned countries should “keep their eyes open” as the threat of the virus is still present.

During a press conference in Geneva on Monday, Dr Ryan said Germany and South Korea should not be criticised for new spikes in Covid-19 cases as, unlike other countries, they have been “alert” and “reacting quickly”.

He said: “The virus is still here a lot more in other countries, so the warning to everyone is, as restrictions are lifted, people will mix more, that is undoubted, and they will maintain physical distance, but the risk of transmission will potentially go up.

“The question is, can we reach a point where we have strong public health measures in place where we can investigate clusters of cases and suppress those clusters without going back to the intense transmission patterns of before?

“We’ve seen a situation where people come together in a crowded environment, (that) is probably the riskiest situation we face, especially if there still is disease present at the country level.

“There’s a lot to be done, and it’s really important that we hold up examples of countries who are willing to open their eyes and willing to keep their eyes open.

“Shutting your eyes and trying to drive through this blind is about as silly an equation as I’ve seen, and I’m really concerned that certain countries are setting themselves up for some serious blind driving over the next few months.”

Tedros Adhanom Ghebreyesus, WHO director general, said countries should consider three key questions before lifting stay-at-home orders and other restrictions.

He said: “First, is the epidemic under control? Second, is the healthcare system able to cope with a resurgence in cases that may arise after relaxing certain measures?

“Third, is the public health surveillance system able to detect and manage the cases and their contacts and identify a resurgence of cases?

“These three questions can help determine whether lockdown can be relaxed slowly or not. However, even with three positive answers, relaxing lockdowns is both complex and difficult.”

The WHO has also said governments need to consider three factors when considering how to safely reopen schools: legislators having a clear understanding about transmission and severity of Covid-19 in children; the epidemiology of where the school is located; and how to maintain Covid-19 prevention and control measures within the school setting.

Maria Van Kerkhove, the WHO’s technical lead on the Covid-19 outbreak, said: “In terms of making the decision about opening schools, it’s very important to understand the virus circulation in the area of where the schools are, what does it look like? Is there intense transmission in that geographic area?

“Are the schools able to practise physical distances in the school itself? Are there different ways to set up a classroom and play time or lunchtime, so they can keep children physically separate?

“There’s a lot of considerations that need to be taken into account when deciding whether and how to open schools. It’s not just a matter of if they should open, it’s how they should open.”