A medical worker takes swab samples from a resident in Hangu Street of Binhai New Area, north China's Tianjin Municipality. File Photo: Xinhua

After the Chinese mainland reported the first case of Omicron variant on Monday night, local health authority in North China's Tianjin where the mutated variant was detected said on Tuesday that the Omicron case was imported from Europe. 

Gu Qing, director of Tianjin Health Commission, said in an interview with Chinese Central Television that the Omicron variant was detected in a sample of an imported case from Europe. The person had normal temperature when they entered China through Tianjin. 

After an all sealed-off management, the person was transferred to a quarantine spot and diagnosed as an asymptomatic case later. In order to prevent the further spread of Omicron in the city, Tianjin authorities have planned a special treatment area for Omicron infections with a special medical team. So far no other Omicron infections were detected among other passengers with the same flight, according to the authorities.

Tianjin reported an Omicron COVID-19 variant infection from an overseas arrival, the first such case on the Chinese mainland. The patient is receiving treatment at a designated hospital. 

When an expert from the State Council anti-epidemic work group compared it to the Delta variant, which broke through "the line of defense" in South China's Guangdong and was imported into the country, he said the situation was a bit different since the Omicron variant was detected at the entry quarantine spot, showing that China's current epidemic monitoring network is highly effective. 

Wu Hao, an expert of the community epidemic prevention and control group of the joint prevention and control mechanism of the State Council, China's cabinet, said it was not surprising that the Omicron variant was detected on the mainland, adding that almost all the latest domestic outbreaks in recent months have been triggered by imported cases. 

When the Delta variant was found in China, it triggered panic. The scale of transmission of the Delta variant has been even larger than that caused by Omicron. In May, the Delta variant broke through the "defense line" in Guangzhou, capital city of South China's Guangdong, and caused a domestic outbreak. 

"But the difference now is that the Omicron variant was found in border entry quarantine point, which showed that our epidemic prevention and control monitoring network responded very quickly," Wu said. 

Tianjin said on Monday night that the Omicron variant was detected in the respiratory samples of an asymptomatic COVID-19 patient who was diagnosed on Thursday.

According to previous reports, one asymptomatic case was detected in Tianjin on Thursday. The carrier is a Polish national who arrived in Tianjin from Warsaw.

On whether Omicron would break through China's border defense line to cause domestic transmission, the expert said given China's dynamic zero-tolerance strategy, even if the Omicron variant further spreads domestically, it would be contained as soon as possible to reduce the impact on production and daily life.