Objective: To conduct an epidemiological investigation on a cluster of overseas imported cases of coronavirus disease 2019(COVID-19)in Qingtian County, Lishui,so as to provide reference for the prevention and control of COVID-19 imported from abroad. Methods: According to the COVID-19 Prevention and Control Program (FiFth Edition) issued by National Health Commission of China,a field investigation was employed and the close contacts of the case were tracked down ;the real-time reverse transcription polymerase chain reaction (RT-PCR) assay was performed to detect the nucleic acid of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from the sputum specimens or throat swabs of cases;the epidemiological characteristics,source of infection,route of transmission and disposal of the cluster were analyzed. Results: From March 1 to March 6,2020,eight confirmed cases and one asymptomatic case of COVID-19 were reported. Their median age was 33 years old. The nine cases all had no fever,no decrease in leukocyte and lymphocyte levels,and the clinical symptoms of seven cases were not obvious. The asymptomatic case had been tested negative for SARS-CoV-2 for six times,but had been weakly positive for IgM antibody and strongly positive for IgG antibody. Nine cases were all the employees of the same restaurant in Begamo,Italy. They lived in three independent villas and usually had lunch and dinner in the restaurant where they worked. Begamo had COVID-19 epidemic,but the staff of the restaurant did not take any protective measures such as wearing masks and environmental disinfection. Eight cases reported to have cold symptoms in Italy during mid February. Through a closed-loop management of“all people,all sites,all chains ”,such as treatment of current cases,screening and isolation of close contacts and health education,totally 372 close contacts were traced back,yet no fever or respiratory symptoms have been found. Conclusions It was a cluster of COVID-19 cases imported from abroad. The clinical symptoms of the cases were not obvious. Qingtian County adopted the closed-loop management in time,and effectively controlled the spread of the epidemic. No second-generation cases have been found.

The role of glial scar after intracerebral hemorrhage(ICH)remains unclear.This study aimed to inves-tigate whether microglia-astrocyte interaction affects glial scar formation and explore the specific function of glial scar.We used a pharmacologic approach to induce microglial depletion during different ICH stages and examine how ablating microglia affects astrocytic scar formation.Spatial transcriptomics(ST)analysis was performed to explore the potential ligand-receptor pair in the modulation of microglia-astrocyte interaction and to verify the functional changes of astrocytic scars at different periods.During the early stage,sustained microglial depletion induced disorganized astrocytic scar,enhanced neutrophil infiltration,and impaired tissue repair.ST analysis indicated that microglia-derived insulin like growth factor 1(IGF1)modulated astrocytic scar formation via mechanistic target of rapamycin(mTOR)signaling activation.Moreover,repopulating microglia(RM)more strongly activated mTOR signaling,facilitating a more protective scar formation.The combination of IGF1 and osteopontin(OPN)was necessary and sufficient for RM function,rather than IGF1 or OPN alone.At the chronic stage of ICH,the overall net effect of astrocytic scar changed from protective to destructive and delayed microglial depletion could partly reverse this.The vital insight gleaned from our data is that sustained microglial depletion may not be a reasonable treatment strategy for early-stage ICH.Inversely,early-stage IGF1/OPN treatment combined with late-stage PLX3397 treatment is a promising therapeutic strategy.This prompts us to consider the complex temporal dynamics and overall net effect of microglia and astrocytes,and develop elaborate treatment strategies at precise time points after ICH.