It is “very important” to get quick results from coronavirus tests in order to implement the public health measures that are needed to control Covid-19, World Health Organization officials said at a press conference in Geneva on Monday.

“It’s very important that when you have a test that is done, that you have the answers to that test quickly,” said Maria Van Kerkhove, WHO’s technical lead for coronavirus.

Unfortunately, she said, there are many parts of the world where it takes quite a long time to get test results back.

“We need individuals to know if they have this virus, so that we know which actions need to be taken,” Van Kerkhove said.

Once someone has been confirmed to be infected with the virus, whether they have symptoms or not, they need to be isolated – and knowing that they are infected means that contact tracing can be carried out.

“This is what breaks chains of transmission,” Van Kerkhove said. “If we have results back in four or five days, even longer, that is not going to help us.”

Having rapid tests in development is a positive thing and will help control efforts, she said.

Van Kerkhove also pointed out that WHO teams are working with their partners across the globe to quickly evaluate rapid tests to see how well they perform, and that they give accurate results.

Dr. Mike Ryan, executive director of WHO’s Health Emergencies Programme, reiterated the importance of quick test results.

“Getting the time from testing to confirming the status of the patient is the single most important thing,” he said. “There’s no point having a test result a week later, when the public health action is late.”

In places where there is limited capacity in laboratories, Ryan said, “You must focus on trying to detect suspect cases, confirming those cases, isolating those cases, quarantining contacts, and … taking all of the measures necessary.”

He called this the most efficient use of testing at the current time.