Paris (AFP)

The multiplication of new cases of coronavirus outside of China reinforces the alarm call of the WHO on the risk of propagation of the epidemic, estimate Sunday experts, by calling to reinforce vigilance.

"The Covid-19 epidemic has experienced a major turning point in the past 48 hours. WHO and its member states must now consider moving from a containment strategy to a mitigation strategy, reduction of the negative impacts of the continued transmission "of the virus, said Professor Devi Sridhar, head of the Health Governance program at the Faculty of Medicine in Edinburgh (Great Britain).

Friday, the head of the WHO, Tedros Adhanom Ghebreyesus had already sounded the alarm: "As we speak, we are still in a phase where it is possible to contain the epidemic." But the "shooting window shrinks".

In particular in question the multiplication of cases out of the cradle of the epidemic in China "without clear epidemiological link, such as travel history or contacts with a confirmed case".

Foci have appeared or developed rapidly in recent days in South Korea, Iran - particularly deadly with 8 deaths for 43 cases listed on Sunday - or in Italy, where nearly 150 cases of coronavirus were recorded in a few days and 11 cities in quarantine. In this country, the most affected in Europe, three people died.

- "Anywhere in the world" -

"This is called the transition to community transmission", explains Professor Arnaud Fontanet, head of the unit "epidemiology of emerging diseases" at the Pasteur Institute (France). "It makes control much more difficult and it suggests a risk of introduction from places other than China."

This is how cases reported in Lebanon and Canada are believed to have originated in Iran. As for the indigenous infectious focus in Italy, scientists are struggling to identify the contamination process of "patient 1" at the origin of the spread.

"What is happening in Italy and South Korea could happen anywhere in the world," warns Professor Sridhar.

Doctor Nathalie MacDermott, of King's College London, also evokes "very worrying" developments, in particular the difficulty of identifying an individual at the origin of the last epidemic foci.

"This suggests a transmission by an asymptomatic individual, or with few symptoms," said the specialist, who considers "imperative that other countries take these situations into account and strengthen their surveillance of people from affected regions they present or not symptoms "and focus on containing the outbreaks of indigenous infection.

"I think this is a new phase" in the extension of Covid-19, explains Eric D'Ortenzio, epidemiologist at the French National Institute for Health and Medical Research (Inserm).

This specialist also points to the appearance in the new countries affected of "chains of transmission from undetected cases", even if he nuances, while awaiting precise data on the subject, the role of epidemic "drivers" asymptomatic cases.

But for him too the consequences to be drawn are clear: "There must be increasing vigilance, the authorities must reinforce surveillance", whether on indigenous cases or possible imports from epidemic outbreaks.

© 2020 AFP