Brits are being urged to remain vigilant for signs of a nasty bug spreading across the country as cases of “American Covid” continue to surge.

The XFG variant, dubbed with its nickname after wreaking havoc in the United States, has been circulating in the UK for around a year. But health officials have issued an urgent warning as rates spike, with Covid-19 positive test rates climbing to roughly seven per cent in September and hospital admissions rising by approximately 50 per cent during the same timeframe.

Figures from the UK Health Security Agency (UKHSA) reveal cases increased by 13.5 per cent week on week to October 7, while deaths soared by 46.4 per cent week on week to October 2, reaching 41 weekly fatalities.

Hospital admissions also leapt 33.5 per cent as cold, damp weather forces people indoors. Experiencing a sore throat, headache and muscle aches can leave you wondering whether you’ve been struck down with a seasonal bug or something more concerning.

With infections climbing once again, people may be tempted to self-diagnose based on how they’re feeling, but medical experts caution that symptoms often overlap, reports the Daily Star.

Dr Neel Patel, Associate Medical Director at Lloyds Pharmacy Online Doctor, suggests that the duration and progression of an illness could offer some clues, though these elements alone cannot conclusively determine which infection you’re battling.

He said: “People with flu normally feel very unwell for two or three days and will continue to experience symptoms for around another five days. After that, you may feel tired and run down for a further two or three weeks. However, people with coronavirus usually begin to show symptoms five to six days after being exposed, and symptoms commonly last up to two weeks.”

Dr Patel also cautioned that the two conditions can be challenging to tell apart. He said: “It can be difficult to tell coronavirus apart from the flu as they share many of the same symptoms; however, they may feel more intense than having the flu.”

He explained that the only reliable way of confirming Covid-19 is to undergo a test, rather than depending purely on how long symptoms persist. Dr Patel added: “While Covid-19 tests are no longer freely available on the NHS, you can still buy lateral flow, PCR and antibody tests online.”

If you feel too poorly to perform everyday tasks, official guidance advises remaining at home. For those unable to do so, the UKHSA recommends wearing a “well-fitting face mask” with multiple layers or a surgical face mask, steering clear of busy areas, exercising outdoors, and washing hands frequently.

Dr Patel warns that urgent medical care is needed if you experience difficulty breathing while at rest, confusion, loss of consciousness or unusual drowsiness, persistent chest pain or pressure, cold or blue-tinged skin, or a sudden loss of speech or movement. The NHS advises calling 999 for severe breathing difficulties, sudden chest pain, collapse or any other potentially life-threatening symptoms.

Read More: American COVID cases rise in UK as expert shares key symptoms to watch for