Analysis of epidemic characteristics of COVID-19 clusters in Chenzhou， Hunan Province / 上海预防医学

Objective:To analyze the epidemiological characteristics of 8 clusters of coronavirus disease 2019 （COVID-19） in Chenzhou City， and provide scientific basis for epidemic prevention and control. Methods:Descriptive epidemiological analysis was conducted for 8 COVID-19 clusters， comparing and analyzing the differences of infection rates among close contacts within and outside the family， and emphatically describing two typical cases. Results:8 COVID-19 clusters were reported in Chenzhou with a total of 31 cases from January to February， 2020. The main source of infection of the family index cases was Hubei Province. Cough symptoms were observed in 67.74% of the cases， followed by fever （54.84%）. The infection rate of close contacts within the family （55.00%） was higher than that outside the family （2.56%）， and the difference was statistically significant （χ2=28.177， P<0.001）. The infection rate of spouse of the family index cases was 85.71%， higher than that of parents （77.78%）， other family members （44.44%） and children （40.00%）， and the difference was not statistically significant （χ2=6.004， P=0.120）. Two typical cases suggested that both COVID-19 pre-symptomatic and asymptomatic patients have the potential to excrete the virus from the body and become sources of infection. Conclusion:Effective family prevention and control measures and early sampling and screening of people in key epidemic areas are conducive to early detection， early isolation and early treatment of infected people， so as to avoid the occurrence and spread of family clusters.

Application of serum antibody detection in the identification of transmission chain of COVID-19 / 上海预防医学

Objective To explore the transmission chain of COVID-19 by serum antibody detection, and to provide scientific evidence for the prevention and control of the epidemic. Methods Field epidemiological investigation was used to determine the COVID-19 cases and their close contacts. The 2019-nCoV nucleic acid in throat swabs and anal swabs were examined by RT-PCR. Serum specimens were collected for anti-2019-nCoV IgM antibody detection and combined IgM/IgG detection. Results Case A had no confirmed exposure to COVID-19. However, case C and D had dinner and lived together with case A; they reported contact history and dinner history with other confirmed COVID-19 cases(H, L). Case A tested positive for 2019-nCoV nucleic acid, whereas case C and D were negative. Moreover, case A and C were IgM antibody positive, while case D was negative. Case A, C and D were all positive for combined IgM/IgG. In addition, case D had clinical symptom, while case C did not. Conclusion Serum antibody detection can be used as an effective supplement to the inference of transmission chain of COVID-19, which may facilitate determining the source of infection and improving the evidence.

Epidemiological survey on a family aggregation COVID-19 in Y County, Chenzhou City, Hunan / 上海预防医学

Objective To investigate epidemic characteristics of a family aggregation COVID-19, and to provide scientific basis for prevention and control of family aggregation epidemic. Methods] Field epidemiological methods were used to investigate the cases and close contacts of a family aggregation COVID-19 in Y County, Chenzhou City, Hunan Province. Descriptive statistical analysis was used on epidemiological data . The 2019-nCoV nucleic acid was detected by real-time fluorescence quantitative RT-PCR. Results It was found that Ms. Deng was infected with COVID-19 and became the infectious source of the family aggregation epidemic , who had lived in Wuhan Hubei Province. Her boyfriend Mr. Cao became a second-generation case of COVID-19..Another two asymptomatic but infected persons were family members living with Ms.Deng . Conclusion COVID-19 easily spreads within families. The awareness of family members' protection, the education of new coronavirus pneumonia prevention and control in key groups should be strengthened to avoid the occurrence and spread of family aggregation epidemic.

[Epidemiological characteristics of imported malaria in Chenzhou City, Hunan Province from 2010 to 2017].

OBJECTIVE: To study the epidemiological characteristics of imported malaria in Chenzhou City, Hunan Province, so as to provide the reference for consolidating the malaria elimination and formulating the prevention and control strategies of imported malaria. METHODS: The epidemiological characteristics of imported malaria were statistically analyzed in Chenzhou City from 2010 to 2017. RESULTS: Totally 46 malaria cases, which were all imported, were reported in Chenzhou City from 2010 to 2017, with an average annual incidence of 0.12/105. The reported malaria cases were mainly falciparum malaria, accounting for 60.87% of the total number of cases. There was no obvious seasonal distribution of malaria cases, but the top of reported cases were in June. Totally 73.91% of malaria cases were concentrated in Beihu District, Suxian District, Guiyang County and Zixing City. These cases were mainly the young and middle-aged and 69.57% of the cases were from 36 to 60 years old. There was a statistically significant difference in the distribution of malaria patients among the age groups (χ2 = 47.80, P < 0.01). The median time from onset to diagnosis was 6 days, and the case confirmed institutions were dominated by municipal and above medical institutions, accounting for 52.17% of the total number of cases. There was a statistically significant difference in the proportion of confirmed cases among medical and health institutions at all levels ( χ2 = 41.96, P < 0.01). CONCLUSIONS: The importation of malaria in Chenzhou City is still severe. The awareness of malaria diagnosis and treatment in primary medical institutions, malaria patients' serum tests, and the health education of malaria control and prevention knowledge should be strengthened to consolidate the malaria elimination results.

Epidemiological characteristics of imported malaria in Chenzhou City, Hunan Province from 2010 to 2017 / 中国血吸虫病防治杂志

Objective To study the epidemiological characteristics of imported malaria in Chenzhou City, Hunan Province, so as to provide the reference for consolidating the malaria elimination and formulating the prevention and control strategies of imported malaria. Methods The epidemiological characteristics of imported malaria were statistically analyzed in Chenzhou City from 2010 to 2017. Results Totally 46 malaria cases, which were all imported, were reported in Chenzhou City from 2010 to 2017, with an average annual incidence of 0.12/105. The reported malaria cases were mainly falciparum malaria, accounting for 60.87% of the total number of cases. There was no obvious seasonal distribution of malaria cases, but the top of reported cases were in June. Totally 73.91% of malaria cases were concentrated in Beihu District, Suxian District, Guiyang County and Zixing City. These cases were mainly the young and middle-aged and 69.57% of the cases were from 36 to 60 years old. There was a statistically significant difference in the distribution of malaria patients among the age groups (χ2 = 47.80, P < 0.01). The median time from onset to diagnosis was 6 days, and the case confirmed institutions were dominated by municipal and above medical institutions, accounting for 52.17% of the total number of cases. There was a statistically significant difference in the proportion of confirmed cases among medical and health institutions at all levels ( χ2 = 41.96, P < 0.01). Conclusions The importation of malaria in Chenzhou City is still severe. The awareness of malaria diagnosis and treatment in primary medical institutions, malaria patients' serum tests, and the health education of malaria control and prevention knowledge should be strengthened to consolidate the malaria elimination results.

Epidemiological characteristics of imported malaria in Chenzhou City, Hunan Province from 2010 to 2017 / 中国血吸虫病防治杂志

Objective To study the epidemiological characteristics of imported malaria in Chenzhou City, Hunan Province, so as to provide the reference for consolidating the malaria elimination and formulating the prevention and control strategies of imported malaria. Methods The epidemiological characteristics of imported malaria were statistically analyzed in Chenzhou City from 2010 to 2017. Results Totally 46 malaria cases, which were all imported, were reported in Chenzhou City from 2010 to 2017, with an average annual incidence of 0.12/105. The reported malaria cases were mainly falciparum malaria, accounting for 60.87% of the total number of cases. There was no obvious seasonal distribution of malaria cases, but the top of reported cases were in June. Totally 73.91% of malaria cases were concentrated in Beihu District, Suxian District, Guiyang County and Zixing City. These cases were mainly the young and middle-aged and 69.57% of the cases were from 36 to 60 years old. There was a statistically significant difference in the distribution of malaria patients among the age groups (χ2 = 47.80, P < 0.01). The median time from onset to diagnosis was 6 days, and the case confirmed institutions were dominated by municipal and above medical institutions, accounting for 52.17% of the total number of cases. There was a statistically significant difference in the proportion of confirmed cases among medical and health institutions at all levels ( χ2 = 41.96, P < 0.01). Conclusions The importation of malaria in Chenzhou City is still severe. The awareness of malaria diagnosis and treatment in primary medical institutions, malaria patients' serum tests, and the health education of malaria control and prevention knowledge should be strengthened to consolidate the malaria elimination results.

[Pathogen spectrum and epidemic status of major human parasites in Chenzhou City, Hunan Province].

OBJECTIVE: To understand the pathogen spectrum and epidemic status of major human parasites in Chenzhou City, Hunan Province, so as to provide the evidence for parasitic diseases control. METHODS: The survey sites were selected by the stratified cluster sampling method. The intestinal helminthic eggs were detected by Kato-Katz technique. The trophozoites or cysts of intestinal protozoa were detected by saline smear and iodine staining methods. The eggs of Enterubius vermicularis of children from 3 to 6 years old were detected by the cellophane anal swab method. The species of hookworm were identified by the filter paper strip culture method. RESULTS: A total of 7 031 people were detected with the intestinal helminthic infective rate of 1.83% (129 cases). The major parasite was hookworm and there was a statistically significant difference of the infection rates among various parasites (χ2 = 107.77, P < 0.01). All the hookworm larvae were Necator americanus. No intestinal protozoon was detected. There were statistically significant differences of the infection rates among the counties (χ2 = 25.77, P < 0.01). The age of the patients was mainly focused on 30 and above years old and the infection rate was increased with the growth of age (χ2 = 26.21, P < 0.01). Farmers were the main population of the patients and there was a statistically significant difference of the infection rates between farmer and others (χ2 = 29.67, P < 0.01). CONCLUSIONS: The infection rates of parasites are low and hook-worm is the main parasite in the pathogen spectrum in Chenzhou City. However, the infection factors still exist, therefore, effective and scientific measures should be taken to consolidate the achievement.

Analysis of the monitoring results of iodized salt consumed by residents in Chenzhou city of Hunan province from 2008 to 2011 / 中国地方病学杂志

Objective To understand and master the situation of residents consumption of iodized salt in Chenzhou city of Hunan province,to identify problems and take appropriate interventions to ensure the residents consumption of qualified iodized salt,and to provide a scientific basis for elimination of iodine deficiency disorders (IDD).Methods According to the National Iodized Salt Monitoring Program (Amendment) and the Evaluation Scheme for Elimination of Iodine Deficiency Disorders at the County Level,the monitoring counties,towns and villages were selected in Chenzhou city from 2008 to 2011,the content of iodine in salt was detected using direct titration.The data was analyzed by SPSS 17.0 and Excel 2003.Results A total of 12700 salt samples were tested from 2008 to 2011.The iodized salt coverage rate,the qualified rate of iodized salt,the consumption rate of qualified iodized salt and the rate of non-iodized salt was 99.19％ (12597/12700),96.33％ (12135/12597),95.55％(12135/12700) and 0.81％ (103/12700),respectively.There were significant differences between each year from 2008 to 2011 (x2 =13.99、42.35、48.45、13.99,P all ＜ 0.01).The coefficient of variation was 21.19％.The median and average of iodine content in salt samples was 32.2 mg/kg and 31.9 mg/kg,respectively.Compared with the median and average of iodized salt content,there was no significant difference between each year from 2008 to 2011 (t =2.941,P ＞ 0.05),while there was significant difference among the 11 counties(t =2.983,P ＜ 0.05).Conclusions The goal of eliminating IDD has realized in the city of Chenzhou since 2010.To consolidate the IDD control results,surveillance should be strengthened in future.