Cases of "American Covid" are on the rise in the UK. The latest strain of the virus, officially called XFG or Stratus, comes from North America but now accounts for more than half of all positive tests in the UK.
The most common symptoms are congestion, cough, fever, headache, runny nose, muscle aches, and a sore, hoarse throat. Experts say a scratchy throat that makes your voice croaky is the most unique symptom distinguishing XFG from other strains.
Cases and hospital admissions surge
The latest figures show 4,589 Covid cases were recorded last month, marking an increase of around 230% on August's figures (1,374). There was also a big uptick in hospital admissions, from 950 in August to 4,939 in September.
Meanwhile, the percentage of tests in hospitals that came back positive for Covid rose from 5.9% to 7.0% in the seven days leading up to September 30, according to figures from the UK Health Security Agency (UKHSA).
Origin and expert assessment
XFG was actually first detected in Southeast Asia in 2025 before becoming dominant in the US. Mutations are thought to have made XFG more infectious than previous strains.
Alex Allen, consultant epidemiologist at the UKHSA, said: "The strains currently going around, including those known as XFG, are closely related to strains that have been with us for over a year, so this isn’t something new."
Though the variant may have greater transmissibility, which, along with seasonal patterns, may be contributing to rising cases, there's no evidence to suggest it causes more severe illness. The vaccine being made available this winter for older and vulnerable people has been designed to be effective against XFG and its variants, The Independent reports.
NHS guidance on symptoms and recovery
"The symptoms are very similar to symptoms of other illnesses, such as colds and flu," the NHS website adds. "Most people feel better within a few weeks, but it can take longer to recover. For some people, it can be a more serious illness and their symptoms can last longer."
The NHS says you should "try to stay at home and avoid contact with other people" if you or your child has symptoms and either have a high temperature, or don't feel well enough to go to work, school, childcare, or do your normal activities. "You can go back to your normal activities when you feel better or do not have a high temperature," it adds.
