The recent coronavirus outbreak in the eastern Chinese city of Nanjing originated from a flight from Russia, said Ding Jie, deputy director of the municipal center for disease control and prevention, on Friday.
So far, the viral genome sequencing of 52 cases in the outbreak showed that the new cases were highly homologous, suggesting the same transmission chain, and all strains were found to be the highly infectious Delta variant, Ding told a press conference.
Among them, the genetic sequence of the virus in earlier reported COVID-19 cases among cabin cleaners is consistent with an imported case reported on Flight CA910 arriving in Nanjing from Russia on July 10.
It is believed that the cleaners did not strictly follow anti-epidemic guidelines after cleaning Flight CA910 and contracted the virus as a result. The infection further spread to other colleagues, who are also responsible for cleaning and transporting garbage on both international and domestic flights.
As of Thursday, Nanjing had reported 184 confirmed cases and one asymptomatic infection case since July 20. Related infections have also been reported in other provinces and municipalities, including Beijing, Sichuan, Hunan and Liaoning.