A British man who contracted the new coronavirus while attending a conference in Singapore may have infected seven other people when he stopped off at a chalet in a French mountain village for a few days on his way home, health experts said on Sunday.
The man, Britain's third case of the virus, stayed with a group of holidaymakers for four days in the chalet in Les Contamines-Montjoie late last month.
Five other Britons in the Alpine ski resort have since tested positive for the coronavirus, French officials said this weekend, linking the cases to the chalet group.
The trail does not appear to end there, however. The disease carried by the same man may have spread elsewhere, underlining the challenges health authorities face in containing infections in an era of global air travel.
Spanish authorities said on Sunday that a British man had tested positive in Mallorca after coming into contact with an infected person in France, whom they said appeared to have been part of the chalet group.
British health officials, meanwhile, said on Sunday that the country had recorded its fourth case of coronavirus, and the person had caught the illness from a Briton while in France.
"This new case would appear to be linked to the cluster of cases in the French ski resort," said Paul Hunter, professor in medicine at England's University of East Anglia. "As such, this case is part of the same cluster which is being reported as linked to a British national returning from Singapore."
However, more broadly, while the outbreak of the new coronavirus has spread to at least 27 countries and territories, according to a Reuters count, only a tiny fraction of cases - about 330 out of over 37,000 - have been outside mainland China.
Residents of Les Contamines-Montjoie, a few wearing facemasks, lined up on Sunday to get tested for the new coronavirus as authorities sought to contain the spread.
French officials said they were tracing all the people who might have been in close contact with the group of 11 Britons exposed to the virus after sharing lodgings in the village.
Five of those tested positive, including a nine-year-old child and their father. Two other children - the infected child's siblings - were hospitalised in France for checks, officials added.
Their mother had left the country by the time the investigation began and was under observation in a UK hospital, French officials said. It was not clear if she was the latest case to be diagnosed in Britain.
Spanish authorities said the British man who had tested positive in Mallorca was one of four members of a family taken into observation on Friday after coming into contact with someone in France who was subsequently diagnosed with the virus.
The family appear to have been part of the larger group in the French ski resort, Fernando Simon, director of the Centre of Coordination of Health Emergencies at Spain's Health Ministry, told reporters.
However he said he could not confirm this 100% because of respect for the family's privacy.
The family returned to Mallorca from France on Jan. 29 and the father started to show light symptoms 24 hours later.
Simon said the man was currently "in good health" but was being kept in isolation and authorities were drawing up a list of everyone he may have come into contact with in Mallorca.