Qualitative Study on Psychological Experience of Close Contacts with COVID-19 during the Centralized Isolation Medical Observation Period / 中国医学伦理学

To analyze the psychological experience of close contacts with COVID-19 during the centralized isolation medical observation (centralized isolation for short) period, 17 close contacts of COVID-19 who received medical isolation observation at designated locations in a city of China were selected by purposive sampling using qualitative study methods, and the interviewees were interviewed by full-coverage structured telephone. By analyzing the obtained data and summarizing the themes, it was found that the psychological status of the COVID-19 close contacts during the centralized isolation period could be classified into three themes: obvious negative emotions, somatization of psychological problems, and demand for social support. During the epidemic, when close contacts were quarantined as high-risk groups, they often had complex and difficult psychological experiences. Relevant departments should actively carry out online guidance channels and offline knowledge dissemination, actively conduct psychological interventions for close contacts, assist them to develop life plans to enrich the life of the centralized isolation period. At the same time, relevant departments should do a good job in logistics and life support services, create a comfortable isolated living environment, and effectively relieve the negative emotions of close contacts of COVID-19 during centralized isolation through a variety of positive and effective measures to ensure physical and mental health.

Evaluation of screening methods for the students who had close contact with pulmonary tuberculosis patients in Shanghai / 上海预防医学

ObjectiveTo evaluate the current screening methods for the students who were in close contact with tuberculosis patients， that could accurately identify the preventive treatment subjects， and to improve the tuberculosis prevention and control in Shanghai schools. MethodsThe freshman/sophomore who were in close contact with active tuberculosis patients in the colleges in 2019 were recruited. All the subjects underwent both tuberculin skin test （TST） and QuantiFERON-TB gold in-tube （QFT） test at the enrollment. After signed the informed consent， all of the participants filled in a questionnaire and determined their baseline tuberculosis infection status. They were followed up for 2 years to monitor the conversion of infection status and the incidence of tuberculosis. ResultsFour of 9 （44.4%） positive participants had conversion to negative results， and 5 of 300 （1.7%） negative participants had conversion to positive during the 2-year follow-up， one of which was diagnosed with active tuberculosis. We assessed diagnostic agreement between QFT and TST at different cut-off values. The highest coincidence rate was 94.0% when choosing 15 mm as the cut-off value， with Kappa coefficient of 0.45 （95%CI： 0.32‒0.59）. ConclusionAlthough stricter than the national work requirements， the prevention and control of tuberculosis in Shanghai schools still need to be carried out meticulously. It's necessary to strengthen daily prevention and control measures， and improve the ability of management.

Detección de SARS-CoV-2 en contactos estrechos asintomáticos de casos confirmados por diagnóstico molecular, provincia de Buenos Aires, Argentina / Detection of SARS-CoV-2 in asymptomatic close contacts of cases confirmed by molecular diagnosis, Buenos Aires province, Argentina

Resumen La detección de SARS-CoV-2 y su implicancia en el diagnóstico de COVID-19 han sido muy debatidas en la pandemia. El objetivo de este estudio fue evaluar el costo/beneficio de la detección de SARS-CoV-2 en contactos estrechos asintomáticos (CE) mediante el uso de distintas pruebas de diagnóstico molecular. Se estudiaron 51 CE de personas con diagnóstico de SARS-CoV-2 confirmado por RTqPCR, clasificadas por el umbral de ciclos (Ct) (<20, entre 20 y 30 y >30) en hospitales públicos de la provincia de Buenos Aires. Del total de contactos estudiados el 15,7% resultó confirmado para SARS-CoV-2; no hubo contactos positivos de casos con Ct>30. La cantidad de contactos positivos de casos con Ct<20 fue significativamente mayor que la de casos con Ct>20. Las muestras con Ct<20 se asociaron a una carga viral estimada de entre uno a cuatro órdenes de magnitud de diferencia con los rangos de Ct>20. Un 13,7% de contactos positivos fueron casos con Ct<20. De las muestras positivas confirmadas por PCR, correspondientes a la semana epidemiológica 1 de 2021 (SE1), sólo un 19,35% correspondían a muestras con Ct<20 y un 50,7% con Ct entre 20 y 30. Estos datos muestran un incremento de sólo un 3,7% de casos detectados. El esfuerzo por parte del sistema de salud pública para esta estrategia, con bajo poder predictivo, puede tener un efecto negativo para el cumplimiento del aislamiento de los contactos y podría generar una demora en los resultados de los casos sospechosos, sin aportar significativamente en el control de la pandemia.

Abstract The detection of SARS-CoV-2 and its implication in the diagnosis of COVID-19 have been highly debated in the pandemic. The objective of this study was to evaluate the cost/benefit of detecting SARS-CoV-2 in asymptomatic close contacts (CC) using different molecular diagnostic tests. A total of 51 CC of people with a diagnosis of SARS-CoV-2 confirmed by RTqPCR, classified by the cycle threshold (Ct) (<20, between 20 and 30 and >30), were studied in public hospitals in the Province of Buenos Aires. Of the total contacts studied, 15.7% were confirmed for SARS-CoV-2; there were no positive contacts of cases with Ct>30 positive. The number of positive contacts of cases with Ct<20 was significantly higher than that of cases with Ct>20. Samples with Ct<20 were associated with an estimated viral load of one to four orders of magnitude difference with Ct ranges >20. A total of 13.7% of positive close contacts were from cases with Ct<20. When studying positive samples with confirmed diagnosis by PCR, corresponding to 1 epidemiological week of 2021 (EW1), only 19.35% corresponded to samples with Ct<20 and 50.7% with Ct between 20 and 30. From these data it is shown that with the CC test only 3.7% of the cases were detected. The effort by the public health system for this strategy, with low predictive power, may have a negative effect on the fulfillment of the isolation of contacts and could generate a delay in the results of suspected cases, without contributing significantly to controlling the pandemic.

Resumo A detecção do SARS-CoV-2 e seu envolvimento no diagnóstico da COVID-19 têm sido muito discutidos durante a pandemia. O objetivo desse estudo foi avaliar a relação custo/benefício na detecção de SARSCoV- 2 em casos de contatos próximos assintomático (CP), por meio do uso de diferentes testes de diagnóstico molecular. Foram estudados 51 casos de CP de pessoas com diagnóstico de SARS-CoV-2 confirmado pelo RTqPCR, sendo classificados pelo limiar de ciclos (Ct) (<20, entre 20 e 30 e >30), em hospitais públicos da província de Buenos Aires. Do total de contatos estudados, 15,7% foram confirmados para SARS-CoV-2, não houve contatos positivos de casos com Ct>30. O número de contatos positivos de casos com Ct<20, foi significativamente maior que os casos com Ct>20. As amostras com Ct<20 foram associadas a uma carga viral estimada de uma a quatro ordens de magnitude de diferença com os intervalos de Ct>20. Dos casos positivos, 13,7% foram com Ct<20. Das amostras positivas confirmadas por PCR, correspondentes à semana epidemiológica 1 de 2021 (SE1), apenas 19,35% correspondiam a amostras com Ct>20 e 50,7% com Ct entre 20 e 30. Esses dados mostram incremento de apenas 3,7% de casos detectados. O esforço por parte do sistema de saúde pública para essa estratégia, com baixo poder preditivo, pode ter um efeito negativo no cumprimento do isolamento dos contatos e poderia gerar uma demora nos resultados dos casos suspeitos, sem contribuir significativamente para o controle da pandemia.

Epidemic Characteristics of the Novel Coronavirus Delta Variant in Guangzhou and Grid Crowd Management Based on Public Security Forensic Perspective / 法医学杂志

Abstract： Objective To analyze the first epidemic spread of the novel coronavirus Delta variant in China based on public security forensic perspective, investigate its transmission characteristics, contributing factors, and epidemiologic research experience, and provide a reference for the prevention and control of the epidemic caused by the novel coronavirus variant. Methods Based on the information that public security forensic experts obtained from front-line epidemiologic research, the gender, age, place of residence, transmission route and infectivity of the coronavirus disease 2019 （COVID-19） confirmed cases, asymptomatic infected persons and their close contacts in Guangzhou caused by the novel coronavirus Delta variant were analyzed. The basic reproduction number （R0） during this epidemic in Guangzhou was calculated. Results Among the 153 cases infected with novel coronavirus Delta variant in the epidemic, 63 cases were male and 90 cases were female, their age ranging from 1 to 92 years, with a median age of 49 years. The main route of transmission was close contact, including dining together, co-living, and close contact in the same residential building. There were 31 cases of family clusters, 25 of which were in Liwan District. The epidemic lasted from May 26 to May 29, and the R0 remained above 4.0. After May 30, R0 began to decline and remained below 1.0 from June 7. Conclusion The novel coronavirus Delta variant is highly infectious, the crowd is generally susceptible to infection and family cluster cases are easy to occur. So, it is necessary to precisely prevent and control this strain. Public security forensic experts have both medical literacy and criminal investigation capabilities, they can play a more professional role in epidemic prevention and control.

Moxibustion on mental disorder in close contacts of coronavirus disease 2019: a randomized controlled trial / 中国针灸

OBJECTIVE@#To observe the effect of moxibustion combined with @*METHODS@#A total of 240 close contacts of COVID-19 were randomized into an observation group (120 cases, 18 cases dropped off) and a control group (120 cases, 58 cases dropped off). Conventional observation was adopted in the control group. Moxibustion combined with Daiwenjiu plaster was given in the observation group, moxibustion was applied at Zusanli (ST 36), Hegu (LI 4) and Shenque (CV 8), 10 min each acupoint, once a day; @*RESULTS@#In the follow-up, SRQ-20 score was decreased compared before treatment (@*CONCLUSION@#Moxibustion combined with

An investigation of a family COVID-19 cluster / 上海预防医学

Objective To investigate epidemic characteristics of a family cluster of COVID-19, and to provide reference in improving the criteria for exclusion diagnosis and medical observation of close contacts. Methods Field epidemiological method was used to investigate the cases and close contacts of a family cluster of COVID-19 in Pudong New Area.Descriptive analysis was conducted on epidemiological data.Real-time fluorescence quantitative RT-PCR was used to detect 2019-nCoV nucleic acid in the respiratory tract specimens. Results There were two confirmed cases and one suspected case in the family cluster.The source of infection was Case 1 with a living history in Wuhan, Hubei Province.Case 2 and Case 3, as close contacts, received 14-day medical observation in a centralized isolation site.Case 2 showed symptoms 4 days after the onset of Case 1, and the diagnosis of COVID-19 was excluded after two negative nucleic acid tests during the isolation period.However, after the expiration of isolation, Case 2 was diagnosed positively for COVID-19 and Case 3 was suspected first and then excluded. Conclusion Daily close contact is critical for COVID-19 transmission and is the major cause of family clustering.Once the close contacts show symptoms, diagnosis should be made by combining the results of nucleic acid test, chest CT test, serological test, etc.We suggest to grade the risk of infection for close contacts, and to strengthen the standard of medical observation for close contacts with high risk of infection.

Characteristics of COVID-19 clusters in Lishui / 预防医学

Objective@#To analyze the epidemiological characteristics of coronavirus disease 2019 ( COVID-19 ) clusters in Lishui, so as to provide basis for the prevention and control of COVID-19 clusters.@*Methods@#The data of COVID-19 clusters in Lishui from January 23 to March 29, 2020 were collected through China Disease Control and Prevention Information System-Public Health Emergency Information System, and analyzed time, space, scale, source of infection, exposure and transmission route by descriptive epidemiological method. @*Results@#There were 31 cases in 8 clusters ( about 4 cases per cluster ), with no death. The report time was bimodal, peaked first from January 20 to February 10 with 4 clusters imported from domestic and peaked second from March 1 to 29 with 4 clusters imported from overseas. Qingtian County reported 4 clusters, Liandu District, Yunhe County, Qingyuan County and Jingning County each reported 1 cluster. Thirteen cases were restaurant employees, accounting for 41.94%. The cases were mainly occurred in the condition that exposed in the same family ( 6 clusters ), in the same dinner and car ( 1 clusters ), and in the same party ( 1 clusters ). The exposure modes that caused more cases infected were through the same family (9 cases) and through the same dinner and car ( 6 cases ). There were 3 clusters with first-generation cases, 3 clusters with second-generation cases and 2 clusters with third-generation cases. The recurrence rate of the 8 clusters ranged from 1.49% to 7.69%, with a median of 3.47%. @*Conclusions@#The COVID-19 clusters in Lishui imported from domestic in the early stage and later from overseas. Most cases were reported from Qingtian County, were engaged in catering business, and exposed by living with families.

Potential false-positive rate among the 'asymptomatic infected individuals’ in close contacts of COVID-19 patients / 中华流行病学杂志

Objective@#As the prevention and control of COVID-19continues to advance, the active nucleic acid test screening in the close contacts of the patients has been carrying out in many parts of China. However, the false-positive rate of positive results in the screening has not been reported up to now. But to clearify the false-positive rate during screening is important in COVID-19 control and prevention.@*Methods@#Point values and reasonable ranges of the indicators which impact the false-positive rate of positive results were estimated based on the information available to us at present. The false-positive rate of positive results in the active screening was deduced, and univariate and multivariate-probabilistic sensitivity analyses were performed to understand the robustness of the findings.@*Results@#When the infection rate of the close contacts and the sensitivity and specificity of reported results were taken as the point estimates, the positive predictive value of the active screening was only 19.67%, in contrast, the false-positive rate of positive results was 80.33%. The multivariate-probabilistic sensitivity analysis results supported the base-case findings, with a 75% probability for the false-positive rate of positive results over 47%.@*Conclusions@#In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals’ reported in the active nucleic acid test screening might be false positives.

Analysis of family cluster infection with Novel Coronavirus Pneumonia / 中华急诊医学杂志

Objective@#To explore the regularity and characteristics of the transmission of Novel Coronavirus Pneumonia(NCP) in crowd, for provide a reference for pre-hospital first aid to identify and screen NCP and close contact, at the same time to improve protection awareness and reduce infection rates.@*Method@#Retrospective analysis about the cases of familial aggregation transferred by Beijing Emergency Medical Center between January 20 and February 10, 2020,collect relevant information,including basic information,contact history,symptoms and signs, clinical outcome, etc.@*Results@#The mean incubation period of familial cluster cases was 5.6d,mean time from onset of symptoms to first visit was 1.8d;Among the 5 family cluster cases, 4 had fever,mean body temperature 38ºC, the Sp02 averaged 96%; Among the 5 family cluster cases, 4 had cough, 2 had fatigue, and 1 had dyspnea.@*Conclusion@#People are susceptible to infection to NCP,it spreads easily between close contacts, effective isolation is the focus of prevention and control among family members, it is also one of the difficulties of prevention and control.

Features of close contacts of COVID-19 cases in Jiulongpo District / 预防医学

Objective@#To explore the features of close contacts of coronavirus disease 2019 ( COVID-19 ) cases in Jiulongpo District, Chongqing, so as to provide evidence for the management of close contacts and the control of the epidemic.@*Methods@#Demographic characteristics, contact history and medical records of close contacts of COVID-19 cases in Jiulongpo District from January 22 to April 10, 2020 was collected according to the COVID-19 Prevention and Control Program ( sixth version ) . Descriptive statistical analysis was performed.@*Results@#Totally 602 close contacts were found, and 30 of them were infected, with an attack rate of 4.98%. Twenty-seven cases were diagnosed before February 10. The close contacts mainly aged from 20 to 59 years ( 457, 75.91% ) ; most were relatives of COVID-19 cases ( 219, 36.38% ) , and 64 (10.63%) were medical staff. Most contacted occasionally ( 338, 56.15% ), at home ( 190, 31.56% ) , and through the same meal ( 181, 30.07% ) . The attack rate of close contacts aged 40 years and over was 7.49%, which was higher than 2.37% of those aged under 40 years ( P<0.05 ). The attack rate of close contacts increased with contact frequency ( P<0.05 ) . The attack rates of close contacts were significantly different in different relations with cases, contact places and contact modes ( P<0.05 ); the attack rates of colleagues and relatives were 20.41% and 8.68%; the attack rates of close contacts in the workplace settings and family were 17.54% and 10.00%; the attack rates of sharing the same bed, living in the same room and working in the same room were 44.44%, 18.60% and 17.24%.@*Conclusions @#The close contacts of COVID-19 cases in Jiulongpo District, Chongqing who aged 40 years or above, exposed in family settings and in the workplace were associated with higher risk of infection.

Implementation of centralized quarantine for close contacts in a community of Shanghai during COVID-19 epidemic / 中华全科医师杂志

Since the key point of prevention and control of new coronavirus infection (COVID-19) in the community is to block the spread, the centralized quarantine for close contacts with confirmed or suspected cases is the most effective way in breaking the chain of transmission. A community centralized quarantine site was set up by Fenglin Community Health Service Center for medical observation of close contacts. The detailed plan and management of the centralized quarantine site, and the implementation experiences are introduced in this article to provide reference for medical institutions involved in the prevention and control of COVID-19 epidemic.

An investigation on knowledge,attitude and practice about tuberculosis prevention and treatment among close contacts of tuberculosis patients / 预防医学

Objective To learn the current situation of knowledge,attitude and practice (KAP)about tuberculosis prevention and treatment among close contacts of tuberculosis patients in Yangzhou City and to explore the influencing factors and relationship of KAP.Methods A total of 460 TB(tuberculosis)patients'families in Yangzhou were randomly selected by means of cluster random sampling.And 746 close contacts of tuberculosis patients were investigated by face - to - face interview.Their basic information,knowledge ,belief and behavior of TB were analyzed by descriptive analysis and multivariable logistic regression analysis.Results The overall awareness rate of tuberculosis prevention and control was 58.30% ,and the rate of positive belief was 50.19%,and the behavior holding rate was 59.25%.The multivariable logistic regression analysis showed that diagnostic types,degree of education and location were the major influencing factors. Conclusion Close contacts with low education level and with smear positive patients in the family should be paid more attention.