Doctors reveal unusual symptoms of new Covid variants 'Stratus' and 'Nimbus' that are sweeping the US

Two new Covid variants are making their way across the country with some unusual symptoms.

The strains, XFV, nicknamed Stratus, and NB.1.81., dubbed Nimbus, are behind a surge in infections across the US as medics issue a stark warning that even mild cases risk inflicting long-lasting effects.

Cases have most notably spiked in the northeast region at the end of August, peaking through mid-September.

According to the CDC, nationwide Covid wastewater levels, which are used to measure community spread of the infection, sit at 'moderate' though it acknowledges at least four US states have 'very high' levels.

The emerging variants are also putting vulnerable groups at risk, namely older adults and people with underlying health conditions or weakened immune systems.

While cases are known to cause some of the typical Covid symptoms - like headaches, fatigue, coughing and a runny or blocked nose, like the flu - doctors are also warning about the strange symptoms the variants are inflicting upon patients and how it is spreading quickly.

Doctors are warning that cases of Covid are on the rise (Getty Stock Image)

Doctor Aaron Glatt, an infectious disease expert from Mount Sinai Hospital in New York, told Today.com that 'severe pain' is a prevailing problem, with patients feeling 'as if their throat is covered with razor blades.'

He added: "While not specific to Covid-19, this expression has been used to describe sore throat symptoms in some patients with the most recent Covid-19 variant."

Others are also warning about declining Covid vaccination rates being behind a possible increase in cases, with a CDC panel voting against recommending the shots for 'individual decision-making'.

Yet an infectious disease specialist, who worked as New York City's chief medical officer during the first wave of the pandemic, warns Coronavirus is 'clearly on the rise again'.

Doctor Tyler Evans told The Daily Mail: "While we’re in a much better place than in 2020, rising transmission still poses a risk to those with underlying conditions or limited access to care. Concern should lead to preparedness, but not panic."

A razor-blade sore throat is one symptom (Getty Stock Image)

He added: "The dominant strain in the US right now is an Omicron subvariant called Nimbus (NB.1.8.1). It spreads quickly but is not more severe than earlier forms."

While it is no more dangerous than its predecessors, Dr Evans said it 'can still be dangerous for older adults, people with chronic conditions, and those with weakened immune systems.'

Doctor Laura Malone, director of the Pediatric Post-Covid-19 Rehabilitation Clinic at Kennedy Krieger Institute in Baltimore, added to the New York Times that even mild infections can pose a long-lasting effect, like long Covid.

"Just because you got through your first infection and didn’t develop long Covid, it’s not that you are completely out of the woods," she explained.

The good news is that Covid wastewater levels are showing signs of slowing down, declining in the week of September 13, though Nevada, Connecticut, Utah and Delaware, meanwhile, are currently recording 'very high' levels.