The photo taken on March 17, 2022 shows a local resident riding an electric motorbike in Beijing. Photo: VCG

Beijing has reported 60 local COVID-19 cases as of Thursday amid the latest outbreak since March 7 with nine transmission chains, including family and school cluster infections. The source of infection of two of the transmission chains is still undetermined. 

Among the nine transmission chains, there are six that involve local infections from regions outside Beijing. There was one family cluster infection reported on March 8 where two children from one family tested positive for COVID-19 in the preliminary screening at the Tongzhou Maternity and Children's Hospital in Beijing. The mother and grandmother were both infected, and the grandmother went back to Beijing on February 28 from other regions, according to health authorities. 

There was one local confirmed patient detected during a closed-loop procedure, who worked as cleaning staff of the Beijing Ditan Hospital and has entered point-to-point closed-loop management since March 3. 

Notably, one of the transmission chains involved 20 confirmed cases but the source is still unclear. On March 14, Beijing reported two students who were infected by the virus. Based on the epidemiological investigation, the students might have been infected in two possible exposures. One is their parents, as they traveled outside Beijing. The other is the possible contact with others at off-campus training centers, according to the health authorities.

The genetic sequencing showed that the virus in one of the students had low homology with previous local or imported cases in Beijing and had high homology with virus sequences uploaded to the international COVID-19 database in January 2022.  

Another transmission chain involved two relatives whose infection source is still undetermined.

Other regions across China also saw a resurgence of COVID-19 recently and the country has continued to implement the "dynamic zero-COVID" policy and allows for a more scientific and targeted response.