Graça Freitas said, at a press conference in Lisbon, that quarantine is measured from the time the plane left the most affected area, in Wuhan, and that is why the 14-day period ends from Saturday to Sunday. "On Saturday they will go home," he said.

The Director-General of Health said that the 20 do not show any symptoms of illness and that on Friday, 14 February, at 9:30am they will repeat the analyzes, with the results available on the same Friday afternoon.

In addition to praising the availability of the 20, 18 Portuguese and two Brazilian women who are isolated at the Curry Cabral hospital in Lisbon, Graça Freitas explained that the Directorate-General for Health (DGS) did not value the study according to the incubation period of the new coronavirus it may not be 14 days, the period followed so far, but 24 days.

This is information “that is not validated”, being “one of the many studies that circulate” and which the World Health Organization (WHO) does not mention, said Graça Freitas, concluding: “if there is no scientific robustness, we cannot consider”, not least because “there are studies that go in the opposite direction”.

The DGS official praised China's efforts to contain the new coronavirus, with measures never seen before, but stressed that it is unknown whether the virus has the capacity to spread to other countries, for which Portugal is preparing, activating and updating contingency plans with “many partners” across the country.

Throughout the press conference Graça Freitas made several references to the much that is still unknown about the new coronavirus, namely not knowing the “attack rate” if it is spread across the planet. "But nothing guarantees us that it will spread," he said.

The Director-General of Health also said that the number of calls to the SNS24 health line has increased, many of them just to ask for information, and admitted that the virus has the capacity to transmit even in warmer weather, even in winter.

The new coronavirus detected in China has already caused more than 43,000 infections and more than a thousand deaths, with only two of the fatalities occurring outside of mainland China, in the Philippines and in Hong Kong.