1. This epidemic situation is caused by a mutant strain in India, with short incubation period, high viral load and fast transmission speed. According to the general law of virus variation, if the spread speed of the mutant increases, the pathogenicity will decrease, but the proportion of asymptomatic infected people in this case is not high (8/131=6%), which may be due to the high viral load of infected people, or it suggests that the pathogenicity of the mutant has not decreased significantly.
2. The transmission chain between the officially announced cases of this epidemic is relatively clear, which shows that after the baptism of fighting against COVID-19 last year and the application of big data, the epidemiological investigation has a high accuracy and can clearly depict the ins and outs of this epidemic. It also shows that there is no large-scale community epidemic in this epidemic, because if there is a large-scale community epidemic, the transmission chain is often difficult to understand.
3. From the perspective of spatial distribution, most of the cases (97/131=74%) are concentrated in Baihedong Street and Zhongnan Street in Liwan District, which are now high-risk areas, and have been closed for management. The rest of the cases were distributed in Foshan (1 cases), Nansha District of Guangzhou (9 cases), Haizhu District of Guangzhou (8 cases), Panyu District of Guangzhou (4 cases), Yuexiu District of Guangzhou (1 case), Maoming City (1 case) and Zhanjiang City (1 case). This also shows that the epidemic is still relatively concentrated.
4. From the source of cases, the vast majority of cases (123/131=94%) were found in key populations and close contacts, which shows that the cases basically came from the control population. Because these control populations are in the state of home or centralized isolation, it is difficult to continue to spread in the community (but it may spread in the family), which is of great significance to cut off the transmission chain and calm the epidemic situation.