Epidemiological characteristics of and containment measures for COVID-19 in Busan, Korea / 한국역학회지

Objectives@#To describe and evaluate epidemiological investigation results and containment measures implemented in Busan, where 108 cases were confirmed with coronavirus disease 2019 (COVID-19) between February 21, 2020 and March 24, 2020. @*Methods@#Any individual who tested positive for COVID-19 was classified as a confirmed case. Measures were taken to identify the source of infection and trace and quarantine contacts. Serial intervals were estimated and the effective reproduction number was computed. @*Results@#Of the total 18,303 COVID-19 tests performed between January 16, 2020 and March 24, 2020 in Busan, 108 yielded positive results (positive test rate, 0.6%). All confirmed cases were placed in isolation at hospitals. Of the 108 confirmed cases, 59 (54.6%) were female. The most common age group was 20-29 years with 37 cases (34.3%). Regarding symptoms at the time of diagnosis, cough (n=38, 35.2%) and fever (n=34, 31.5%) were most common; 12 cases (11.1%) were asymptomatic. The source of infection was identified in 99 cases (91.7%). A total of 3,223 contacts were identified and quarantined. Household contacts accounted for 196, and the household secondary attack rate was 8.2% (95% confidence interval [CI], 4.7 to 12.9). The mean serial interval was estimated to be 5.54 days (95% CI, 4.08 to 7.01). After February 26, (Rt) remained below 1 in Busan. @*Conclusions@#The early containment strategy implemented in Busan shows that control is possible if outbreaks are of limited scope. In preparation for future outbreaks, public health and healthcare systems should be re-examined and put in a ready state.

Epidemiological characteristics of and containment measures for COVID-19 in Busan, Korea / 한국역학회지

Objectives@#To describe and evaluate epidemiological investigation results and containment measures implemented in Busan, where 108 cases were confirmed with coronavirus disease 2019 (COVID-19) between February 21, 2020 and March 24, 2020. @*Methods@#Any individual who tested positive for COVID-19 was classified as a confirmed case. Measures were taken to identify the source of infection and trace and quarantine contacts. Serial intervals were estimated and the effective reproduction number was computed. @*Results@#Of the total 18,303 COVID-19 tests performed between January 16, 2020 and March 24, 2020 in Busan, 108 yielded positive results (positive test rate, 0.6%). All confirmed cases were placed in isolation at hospitals. Of the 108 confirmed cases, 59 (54.6%) were female. The most common age group was 20-29 years with 37 cases (34.3%). Regarding symptoms at the time of diagnosis, cough (n=38, 35.2%) and fever (n=34, 31.5%) were most common; 12 cases (11.1%) were asymptomatic. The source of infection was identified in 99 cases (91.7%). A total of 3,223 contacts were identified and quarantined. Household contacts accounted for 196, and the household secondary attack rate was 8.2% (95% confidence interval [CI], 4.7 to 12.9). The mean serial interval was estimated to be 5.54 days (95% CI, 4.08 to 7.01). After February 26, (Rt) remained below 1 in Busan. @*Conclusions@#The early containment strategy implemented in Busan shows that control is possible if outbreaks are of limited scope. In preparation for future outbreaks, public health and healthcare systems should be re-examined and put in a ready state.

A large outbreak of Salmonella enterica serovar Thompson infections associated with chocolate cake in Busan, Korea / 한국역학회지

OBJECTIVES@#This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak.@*METHODS@#This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested.@*RESULTS@#Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same.@*CONCLUSIONS@#The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.

A large outbreak of Salmonella enterica serovar Thompson infections associated with chocolate cake in Busan, Korea / 한국역학회지

OBJECTIVES: This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak.METHODS: This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested.RESULTS: Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same.CONCLUSIONS: The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.

A large outbreak of Salmonella enterica serovar Thompson infections associated with chocolate cake in Busan, Korea / 한국역학회지

OBJECTIVES: This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak. METHODS: This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested. RESULTS: Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same. CONCLUSIONS: The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.

Advanced algorithms of motion estimation for an elder at living room using Principal Component Analysis / 대한의료정보학회지

OBJECTIVE: Development of telemedicine for an elder has been an important research area in an aging society, and effective Personal Emergency Response System(PERS) can provide exact medical decision and prompt treatment under emergency conditions. Previous studies have been focused on adapting troublesome sensors or passive calling system to monitor the old in their house. However, these previous systems might have limited applications due to its difficulties in usage and restraints in their daily activities, especially in the emergency. METHODS: In this study, the real time algorithms using surveillance camera was developed to monitor their pose change, such as emergency and falling motion. To estimate the motion of elder people, this research use a ratio of eigenvectors of the Principal Component Analysis (PCA) technique. RESULTS: In this system, no additional motion sensors or devices were applied to the object and it can be automatically controlled and monitor the old from a distance. It was found that this system can successfully monitor the old in living room regardless of surveillance camera angles and a silhouette size depending camera distance as using image processing and PCA. CONCLUSION: This algorithm was validated by experiments in a living room and this technique can be applicable to home monitoring and further applications.

Design of Hybrid Multimedia Telemedicine System over Heterogeneous Networks / 대한의료정보학회지

OBJECTIVE: The advancement of computing capabilities and increase of available network bandwidths have resulted in an emergency telemedicine services which can provide high quality medical services. However, existing telemedicine systems mainly have offered a one to one communication configuration instead of a multi-connection configuration. Therefore, we suggested a hybrid multimedia telemedicine system to support the multi-patients services in wired and wireless (heterogeneous) network environments. METHODS: We designed the hybrid multimedia telemedicine system consisting of 4 sub-systems, a patient system, a doctor system, a emergency monitoring system, and a multi-control server system. The patient system could deliver multimedia data of a patient to the emergency monitoring system or to the doctor system according to link configuration. The link configuration was decided as 'Flowing', or 'By-passing' in accordance the connection type of patient systems or doctor systems. At this time, as the multi-control server system considers the hybrid network, it monitored the patient's multimedia data and the state of emergency telemedicine services. RESULTS: The hybrid multimedia telemedicine system including the multi-control server system performed the best communication configuration over heterogeneous networks. This system achieved high quality emergency telemedicine services through dynamic wired and wireless networks at real-time. CONCLUSION: This study represented a hybrid multimedia telemedicine system over heterogeneous networks in emergency cases. We expected that the designed system could provide not only the high quality services, tele-diagnosis and tele-consultation, but also the effective emergency telemedicine services to multi-patients in the heterogeneous network environments.

Transcoder based on Proxy for Transmitting Patients' Video Stream / 대한의료정보학회지

OBJECTIVE: The progress in computer and communication technologies is making the Internet increasingly heterogeneous in terms of network, hardware and software capacities. Moreover, this has made it possible for emergency telemedicine services to provide high quality medical services. However, resource availability on the Internet varies unexpectedly. Thus, providing an efficient access to emergency telemedicine services requires that medical multimedia streams be adapted according to the environment constraints. One approach to this issue is based on the use of intermediate nodes within the network to perform such adaptations (media transformations and data transcoding). For this purpose, we have designed and implemented a proxy server for Quality of Service adaptations of medical multimedia streams. METHODS: We have organized a new emergency telemedicine system by designing a proxy server to execute transcoding. The proxy server is located between a patient system and a doctor system over heterogeneous networks. Before a patient system can deliver medical video streams to a doctor system, the proxy server measures uplink bandwidth which is one of the Quality of Service factors, from the proxy server to the doctor system. At this moment, frame rates are determined according to the measured bandwidth, and the proxy server transmits medical video streams modified for new frame rates to the doctor system. We describe the implementation of this proxy server on top of the Microsoft DirectShow(R) environment and report on a performance evaluation which demonstrates the effectiveness of the approach. RESULTS: The quality of requested medical video streams can be predicted when they are adapted to the receiver. With this prediction, adapted medical video streams which meet the frame rates constraints of the receiver can be delivered without additional measurements of bandwidth. CONCLUSION: This study represents a proxy server of a hybrid multimedia telemedicine system over heterogeneous networks. We expect that the designed proxy server can provide not only dynamic Quality of Service monitoring functions along bandwidth measurement, but also medical video adaptations to the receiver in heterogeneous network environments.