The US has reported the arrival of a new and potentially more contagious strain of Covid-19, following a sharp rise in cases and hospitalisations in China and parts of Asia.
The variant, known as NB.1.8.1, is believed to be behind a recent surge in infections and has now been detected at multiple international airports across the United States.
According to data from the US Centers for Disease Control and Prevention (CDC), travellers from several Asian countries — as well as France, the Netherlands and Spain — have tested positive for the strain upon entry.
There is also evidence that NB.1.8.1 is now spreading locally within the US.
China has seen a dramatic spike in serious Covid cases in recent weeks, with the number of severely ill respiratory patients and the proportion of A&E patients testing positive almost doubling over the past month.
This reflects a similar surge in other Asian countries, with Taiwan dealing with a 78% increase in Covid hospital admissions.
Authorities in Hong Kong say that Covid rates have now climbed to the worst levels seen in at least a year after a "significant increase" in hospitalisations, and citizens are once again being advised to wear face masks in crowed areas.
The World Health Organisation has said that the new variant does not seem to cause a more dangerous illness, but that it could be more transmissible and therefore lead to more rapid infections.
The US conducted voluntary nasal swabs at airports for those entering the country between April 22 and May 12.
The new cases are said to have originated from travellers from China, Japan, Vietnam, South Korea, Taiwan, Thailand, France, the Netherlands and Spain.
Despite fears of rising hospitalisations in the West from NB.1.8.1, and reports of domestic US cases dating back to late March this year, there has been no measures implemented by the US in response, with Covid testing falling by 12% in the latest available data.
