New COVID-19 Variant 'Stratus' Dominant In US: What We Know So Far

A highly transmissible COVID-19 strain is driving a surge of infections across the United States. Nicknamed 'Stratus,' the XFG strain has been spreading in various parts of US. Recent reports suggest that the increase in COVID-19 cases in many states is linked to rising viral levels detected in wastewater surveillance. According to the Centres for Disease Control and Prevention (CDC) data, 19 US states are currently reporting "high" or "very high" levels of COVID in wastewater. However, the CDC also indicated that, as of September 20, viral activity in wastewater remains "moderate" at the national level. CDC's wastewater data shows that the Stratus variant has overtaken the NB.1.8.1 (Nimbus) strain as the dominant variant in many states. While there is no clear evidence that Stratus causes more severe illness than previous variants, the variant has the ability to evade immune system defences, allowing it to spread quickly.

XFG (Stratus) Covid-19 variant: What we know so far

Stratus, which belongs to the Omicron family, is a recombinant variant originating from two other variants, LF.7 and LP.8.1.2. For the unversed, recombinant variants are hybrid strains that occur when a person is simultaneously infected with two different COVID variants, leading to a mixing of genetic material and resulting in a new variant with traits from both strains. First detected in the US in March, XFG is likely to cause mild illness. Experts around the world have highlighted that the overall public health risk from XFG remains low, however, individuals with pre-existing health conditions and those with compromised immunity may experience more severe illness.

Symptoms

The symptoms of XFG are similar to those of other Omicron sub-variants and are typically mild upper respiratory symptoms. These include sore throat, cough, congestion, fever, fatigue, and muscle aches. Stratus often leads to hoarseness and scratchy or sore throats, symptoms that can be mistaken for seasonal allergies. Some individuals may also experience gastrointestinal symptoms such as nausea, vomiting, or diarrhea.

Vaccination

Earlier this year, the World Health Organisation designated XFG as a variant under monitoring, meaning it requires prioritised attention to determine if it poses an additional threat compared to other circulating variants. Additionally, existing vaccines remain effective against symptomatic and severe disease caused by this variant.

Transmission

Stratus seems to spread more easily and partially evade immunity from past infection or vaccination. While it transmits easily, available data do not strongly support increased hospitalisation or mortality rates associated with it.

Precautions to follow:

Vaccination remains important

Though the variant partially evades immunity, vaccines still provide strong protection against severe disease, hospitalisation, and even death.

Get yourself tested and isolate

If symptomatic (especially sore throat, cough, fever), testing and isolating can help reduce transmission.

Use masks

In crowded indoor settings, good ventilation and use of high-quality masks (e.g. N95 / KN95) help reduce risk. Also, practice hand hygiene to control transmission.

Monitoring vulnerable groups

Older adults, immunocompromised individuals, or those with chronic conditions should be especially cautious. Seek immediate medical help if you experience any symptoms.

Stay updated on public health guidance

As surveillance evolves, health agencies may share measures to stay safe.

A rise in flu cases is typically observed during the fall in the US, making it difficult to distinguish between flu and COVID-19. Timely testing can assist in seeking the appropriate medical help.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.