Coronavirus: China's COVID outbreak fueled by Stealth Omicron; here's what it is and symptoms to watch out for

China is grappling with its biggest surge in COVID-19 cases since the Wuhan outbreak. The country reported over 5,200 new cases on Tuesday and about 30 million people are currently under lockdown. The National Health Commission in China has said that about 1,337 locally transmitted cases have been reported in the last 24-hours.

Health officials say that the sudden surge in coronavirus in the country is being driven by the highly transmissible BA.2 sublineage of the Omicron variant, also known as the 'Stealth' Omicron. Here's everything you need to know about it.

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Stealth Omicron or BA.2 is a sub-variant of the highly contagious Omicron variant, with possibly more mutations than its original strain. Currently it is a ‘variant under investigation’.

Studies have said that the BA.2 subvariant is more transmissible than its parent strain. According to a Danish study, it is 1.5 times more transmissible than the original Omicron strain. Apart from China, the sub-variant has become dominant in countries including the Philippines, Nepal, Qatar, Denmark, and India.

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Early findings in Denmark suggest that the Stealth Omicron does not pose any serious risk to life. Just like its parent strain, it does not cause any severe symptoms nor does it increase the risk of hospitalization or death.

However, unlike the original variant, the BA.2 subvariant may have the ability to dodge tracking.

Experts believe the stealth Omicron lacks a mutation, which is integral to the detecting process. According to the U.K. Health Security Agency (UKHSA), COVID's Omicron variant contains a genetic deletion in the “S'' spike gene that makes it easier to track. However, in the stealth Omicron, there is no S gene drop out, which makes iit harder to detect.

The Delta variant continues to remain the most dominant strain around the world. The fact that it attacks the lower respiratory system and causes damage to the lungs is what makes it extremely dangerous.

But unlike the Delta, the World Health Organization (WHO) says that the Omicron variant and its sublineage BA.2 primarily affects the upper respiratory tract. Given that it does not pose any potential risk to the lungs, symptoms like loss of smell and taste, shortness of breath and chest pain are uncommon.

Currently, there is no scientific evidence to tell if the new sub-variant is different from the Omicron, in terms of symptoms.

It's believed that stealth Omicron also causes mild symptoms such as sore throat, runny nose, mild fever and cough.

However, dizziness and fatigue are two of the most common symptoms reported early in patients infected by the stealth Omicron.