[Epidemiological characteristics and measures of prevention and control of imported COVID-19 cases in early phase in Shanghai].

Objective: To analyze the epidemiological characteristics of imported COVID-19 cases in early phase in Shanghai, introduce measures and provide reference for prevention and control of imported COVID-19 cases. Methods: Data of imported COVID-19 cases in Shanghai reported as of 30 March, 2020 were obtained from National Notifiable Disease Report System of China CDC and field epidemiological investigation reports by CDCs in Shanghai. The information about measures of prevention and control was collected from official websites and platforms of the governments. Data cleaning and statistical analysis were performed with softwares of EpiData 3.1, Excel 2019 and SAS 9.4. Results: A total of 171 imported COVID-19 cases had been reported as of 30 March, 2020 in Shanghai, including 170 confirmed cases and 1 asymptomatic infection case. Among them, cases of Chinese nationality accounted for 71.3% (122/171) and cases of foreign nationality accounted for 28.7% (49/171). The median age of the cases was 23 years (P(25), P(75): 18, 35 years), and the male to female ratio of the cases was 1.3∶1. Students accounted for 56.6% (97/171). About 45.6% (78/171) of the cases fell ill before arriving in Shanghai. The cases with mild or common clinical manifestation accounted for 96.5% (165/171) and no significant difference in clinical type was observed between overseas Chinese cases and foreign cases. The epidemic curve by diagnosis date reached peak on March 24, and the number of the cases gradually declined due to the closed-loop management process of joint port prevention and control mechanism. The 171 imported COVID-19 cases were mainly from 24 countries and regions, including the United Kingdom (64 cases, 37.3%), the United States (32 cases, 18.6%), France (19 cases, 11.0%) and Italy (16 cases, 9.4%). About 40.4% of the cases (69/171) planned to continue travelling to 21 other provinces and municipalities in China. Customs quarantine and community observation/detection points identified 43.9% (75/171) cases and 31.0% (53/171) cases, respectively. Conclusions: The imported COVID-19 cases in early phase in Shanghai were mainly young population and students accounted for high proportion. The imported risk of COVID-19 was consistent with the severity of the epidemic in foreign countries. The closed-loop management model of the joint port prevention and control mechanism plays an important role in the identification and management of the imported COVID-19 cases.

[Investigation of an epidemic cluster caused by COVID⁃19 cases in incubation period in Shanghai].

Objective: To analyze the epidemiological characteristics of a cluster of 5 confirmed COVID⁃19 cases related with the transmission in incubation period of initial case, and find out the infection source and transmission chain.. Methods: According to "The Prevention and Control Protocol for Coronavirus Disease 2019 (Third Edition)" issued by the National Health Commission, a field epidemiological survey was conducted for the 5 cases in January 2020. Nasopharyngeal swabs and sputum samples were collected from them for the detection of 2019-nCoV by real time RT-PCR. Multi prevention and control measures were taken, such as tracking and screening close contacts, medical isolation observation, investigating the epidemiological link, analyzing transmission chain. Results: Case 1, who had common environmental exposure with other COVID⁃19 cases, got sick on 20 January, 2020 and was confirmed on 1 February. Case 2 became symptomatic on 22 January and was confirmed on 27 January. Case 3 got sick on 25 January and was confirmed on 30 January. Case 4 had illness onset on 20 January and was confirmed on 1 February. Case 5 got sick on 23 January and was confirmed on 31 January. Among the 5 cases, case 2 died and the illness of other cases were effectively controlled. After exclusion of other common exposure factors, case 1 had a 6-hour meeting with case 2 and case 3 on 19 January. Case 2 and case 3 might be infected by case 1 during the incubation period. It is the key point for epidemiological investigation. Conclusion: The epidemiological investigation indicates that the transmission might occur in the incubation period of COVID-19 case, close attention should be paid to it in future COVID-19 prevention and control.

[Spatial-temporal analysis on the human immunodeficiency virus/acquired immunodeficiency syndrome among permanent residence and migrants in Shanghai, 2005-2015].

Objective: To describe the spatial and temporal characteristics of human immunodeficiency virus/acquired immunodeficiency syndrome(HIV/AIDS) in permanent residents and migrants in Shanghai during 2005 to 2015 and provide suggestions for the HIV/AIDS prevention. Methods: The data of HIV/AIDS was collected from the National HIV/AIDS Comprehensive Information Management System based on report date. The population data was collected from the statistical yearbook of Shanghai. Spatial analysis was conducted using the hotspots model in ArcGIS. SaTScan software was employed to determine the distribution of HIV clusters in space, time or both. Results: During 2005 to 2015, a total of 13 498 cases of HIV/AIDS were reported in Shanghai. The prevalence of HIV increased from 0.025/10(5) (450 cases) to 0.093/10(5) (2 236 cases). The prevalence of AIDS increased from 0.002/10(5) (32 cases) to 0.028/10(5) (683 cases). Hotspot analysis showed that the hot spot of incidence of migrants had moved from Hongkou (2005) (Z=2.96, P=0.003) to Changning (2006-2015) (all Z>1.96, P<0.05); whereas the hot spot of incidence of permanent residents had moving from Jinshan (2005-2007) (all Z>2.58, P<0.01) to downtown area (2006-2015) (all Z>1.96, P<0.05). The spatial high clusters of HIV and AIDS were same, including Huangpu, Xuhui, Changning, Jingan, Putuo, Hongkou and Yangpu; The temporal high clusters of HIV cases among permanent residents were 2011 to 2015, and the spatial clusters were Huangpu, Xuhui, Changning, Jingan. The temporal high clusters of HIV cases among migrants were 2014 to 2015, and the spatial clusters was Xuhui, Changning, Jingan. Conclusion: The total HIV/AIDS incidence in Shanghai was clustered in downtown area. The cluster of the incidence of the permanent residents had moving towards that of migrants, indicating the cluster area deserves a close surveillance.

[Epidemiologic and spatio-temporal characteristics of hepatitis E in China, 2004-2014].

Objective: To describe and analyze the epidemiologic and spatio-temporal characteristics of hepatitis E in China from 2004 to 2014. Methods: Data on the incidence of hepatitis E in 31 provinces (municipality and autonomous region) from 2004 to 2014, were collected. Empirical Mode Decomposition (EMD) was applied to decompose the time-series data to accurately describe the trend of hepatitis E incidence. Mathematic model was used to estimate the annual change of incidence in each age group and the whole province. Software ArcGIS 10.1 and SaTScan 9.01 were used to analyze the spatio-temporal clusters. Results: During 2004-2014, a total of 245 414 hepatitis E cases were reported in China. The overall incidence showed a slight increase (OR=1.05, 95%CI: 1.03-1.10). Incidence rates on hepatitis E were discovered different across the provinces, with significant increase appearing in the southern, central and northwestern areas. The highest increase was seen in the elderly, especially in the 65-69 and 70-74 year-olds. Results from the Local spatial autocorrelation analysis showed that the "high-high cluster" was moving from the north to the south and the "low-low cluster" disappeared as time went by. Data from Spatio-temporal scanning showed that there were five spatio-temporal clustering areas across the country. Conclusion: The overall incidence of hepatitis E was on the rise from 2004 to 2014, in China, but with differences seen across the areas and age groups.

Myoblast transfer therapy for Duchenne muscular dystrophy.

A randomly selected extensor digitorum brevis (EDB) muscle in each of three Duchenne muscular dystrophy (DMD) boys aged 9 to 10 was injected with approximately 8 x 10(6) myoblasts. The contralateral EDBs were sham-injected with carrier solution. Donor myoblasts were derived from cell culture of muscle biopsies from the normal ward or normal brothers of the recipients. Cyclosporine (CsA) treatment began two days before myoblast injection and continued for three months. Three days prior to myoblast injection and three months after, the isometric twitch and maximum voluntary contraction of the left and the right EDBs were measured. Myoblast-injected EDBs showed increases in tensions whereas sham-injected EDBs showed reductions. Both immunocytochemical staining and immunoblot revealed dystrophin in the myoblast-injected EDBs. Dystrophic characteristics such as fiber splitting, central nucleation, phagocytic necrosis, variation in fiber shape and size, and infiltration of fat and connective tissues were less frequently observed in these muscles. Sham-injected EDBs exhibited significant structural and functional degeneration and no dystrophin. Throughout the study, there was no sign of erythema, swelling or tenderness at the injection sites. Serial laboratory evaluation including electrolytes, creatinine, and urea did not reveal any significant changes before or after myoblast transfer. We conclude that myoblast transfer therapy is a safe and efficacious procedure to improve the biochemistry, structure, and function of degenerative EDB muscles in DMD.

Vital marker for muscle nuclei in myoblast transfer.

A new method is developed using Fluoro-Gold (FG) as a vital stain to label the nuclei of donor myoblasts in myoblast transfer studies. In vitro incubation with 0.01% FG for 16 h resulted in 100% nuclei labelling. Intensive fluorescence persisted following 9 days of subculture, when the human myoblasts were injected into the quadriceps of mouse recipients immunosuppressed with cyclosporine. Injected muscles showed mosaicism of host and donor nuclei 25 days after injection, indicating (i) survival and fusion among donor myoblasts, and (ii) fusion between host and donor cells. FG labelling was not observed in control muscles injected with an equal volume of FG-labelled dead myoblasts, 0.01% FG medium, or phosphate-buffered saline.