Surge in Delta cases: How a flight from Moscow crippled China's COVID defences

As China confronts its largest outbreak since the virus first surfaced in late 2019, the fast-spreading Delta variant appears to have broken through COVID defences. China reported the largest daily number of 71 local coronavirus cases in months on Wednesday. Since July 30, the number of new cases has been rising for the last five days. A trail of Delta variant infections has been discovered through mass testing and contact tracing activities.

Delta variant has been detected in over a dozen cities

Since late July, the highly transmissible Delta variant has been detected in over a dozen Chinese cities, including the capital Beijing. Between July 20 and August 3, China reported 485 locally-transmitted cases with symptoms, however, it's unclear how many of these are in the Delta form. Seventeen provinces, regions, and municipalities had reported locally transmitted cases, both with and without symptoms, as of early Wednesday. Due to the Delta variant's rapid and asymptomatic spread, Chinese officials agree that containing the latest outbreak will be far more difficult than the others.

Delta variant arrived in China from Moscow

In mid-July, the first case of the Delta variant was reported in Nanjing, China, during an international flight from Moscow. On the flight, seven people were infected with the variant. It then spread to a group of airport cleaning employees, with nine of them testing positive for the virus on July 20. It immediately spread among those who entered the airport, which serves as a key traffic centre. Cases appeared as far away as Hainan Island in China's south, 1,900 kilometres from Nanjing, in just a few weeks. 

Domestic flights, long-distance shuttle buses, taxis, and ride-hailing vehicles have been prohibited from entering and leaving Nanjing and Yangzhou in eastern Jiangsu province, where the majority of China's local Delta cases have been reported since July 20, and some bus services have been suspended.

Last Monday, Zhangjiajie, a metropolis of 1.5 million people, blocked off residential areas prohibiting residents from leaving their houses. On Tuesday, officials issued an order prohibiting anyone from leaving the city, whether a tourist or a resident. Since last week, the city has only registered 19 instances, three of which were patients who had no symptoms and were counted separately.
According to the Shanghai government-owned tabloid The Paper, individual cases related to Zhangjiajie's outbreak have spread to at least five provinces.

(Inputs from AP News)