1999년 상반기에 대유행한 Salmonella enterica Serotype Enteritidis 식품매개감염증의 분자역학적 연구

김철현,손장욱,김성한,박미선,강연호,이복권,김호훈,유정식,신영학,김민자 대한감염학회 2000 감염 Vol.32 No.6

Epidemiological characteristics of carbapenemase-producing Enterobacteriaceae outbreaks in the Republic of Korea between 2017 and 2022

Hyoseon Jeong,현정희,이연경 질병관리본부 2023 Osong Public Health and Research Persptectives Vol.14 No.4

Objectives: We aimed to describe the epidemiological characteristics of carbapenemase-producing Enterobacteriaceae (CPE) outbreaks in healthcare settings in the Republic of Korea between 2017 and 2022.Methods: Under the national notifiable disease surveillance system, we obtained annual descriptive statistics regarding the isolated species, carbapenemase genotype, healthcare facility type, outbreak location and duration, and number of patients affected and recommended interventions. We used epidemiological investigation reports on CPE outbreaks reported to Korea Disease Control and Prevention Agency from June 2017 to September 2022.Results: Among the 168 reports analyzed, Klebsiella pneumoniae (85.1%) was the most frequently reported species, while K. pneumoniae carbapenemase (KPC, 82.7%) was the most common carbapenemase genotype. Both categories increased from 2017 to 2022 (p<0.01). General hospitals had the highest proportion (54.8%), while tertiary general hospitals demonstrated a decreasing trend (p<0.01). The largest proportion of outbreaks occurred exclusively in intensive care units (ICUs, 44.0%), and the frequency of concurrent outbreaks in ICUs and general wards increased over time (p<0.01). The median outbreak duration rose from 43.5 days before the coronavirus disease 2019 (COVID-19) pandemic (2017–2019) to 79.5 days during the pandemic (2020–2022) (p=0.01), and the median number of patients associated with each outbreak increased from 5.0 to 6.0 (p=0.03). Frequently recommended interventions included employee education (38.1%), and 3 or more measures were proposed for 45.2% of outbreaks.Conclusion: In the Republic of Korea, CPE outbreaks have been consistently dominated by K. pneumoniae and KPC. The size of these outbreaks increased during the COVID-19 pandemic. Our findings highlight the need for continuing efforts to control CPE outbreaks using a multimodal approach, while considering their epidemiology.

Epidemiological Characteristics of Norovirus Outbreaks in Shenyang from 2017 to 2021

Qi Ying,Dong Xinxin,Cheng Xiaowei,Xu Han,Wang Jin,Wang Bing,Chen Ye,Sun Baijun,Zhang Linlin,Yao Yan 한국미생물학회 2023 The journal of microbiology Vol.61 No.4

Norovirus is one of the leading causes of acute gastroenteritis outbreaks worldwide. This study aimed to identify the epidemiological characteristics of norovirus outbreaks and to provide evidence for public health entities. Specimens and epidemiological survey data were collected to determine if there were differences in the attack rate of norovirus in terms of the year, season, transmission route, exposure setting, and region and to determine whether there were relationships between the reporting interval, the number of illnesses in a single outbreak and the duration of the outbreak. Norovirus outbreaks were reported throughout the year, with seasonal characteristics (i.e., high rates in spring and winter). Among all regions in Shenyang with the exception of Huanggu and Liaozhong, norovirus outbreaks had been reported, and the primary genotype was GII.2[P16]. Vomiting was the most common symptom. The main places of occurrence were childcare institutions and schools. The person-to-person route was the main transmission route. The median duration of norovirus was 3 days (IQR [interquartile range]: 2–6 days), the median reporting interval was 2 days (IQR: 1–4 days), the median number of illnesses in a single outbreak was 16 (IQR: 10–25); there was a positive correlation between these parameters. Norovirus surveillance and genotyping studies still need to be further strengthened to increase knowledge regarding the pathogens and their variant characteristics, to better characterize the patterns of norovirus outbreaks and to provide information for outbreak prevention. Norovirus outbreaks should be detected, reported and handled early. Public health entities and the government should develop corresponding measures for different seasons, transmission routes, exposure settings, and regions.

Resurrecting the ghost of green revolutions past: The brown planthopper as a recurring threat to high-yielding rice production in tropical Asia

Dale G. Bottrell,Kenneth G. Schoenly 한국응용곤충학회 2012 Journal of Asia-Pacific Entomology Vol.15 No.1

The brown planthopper (BPH), Nilaparvata lugens (Stål), which periodically erupted in tropical Asian rice before the 1960s, became a major threat after farmers adopted green revolution technologies in the 1960s. Management and policy changes in the 1980s and 1990s emphasized non-insecticidal tactics to avert BPH outbreaks. However, insecticides have resurfaced as the primary means for controlling rice insect pests and tropical Asian countries have recently experienced planthopper outbreaks in record numbers. Our review of factors that have contributed to the outbreaks points to insecticides as the most tangible outbreak factor primarily because of their harmful effects on natural enemies. BPH resistance to insecticides and especially imidacloprid has increased the probability of outbreaks as farmers have applied increasing quantities of insecticide in an attempt to combat resistant populations. Similarly, heavy use of nitrogen fertilizer, especially on hybrid rice, has increased the potential for outbreaks. Other factors triggering outbreaks are less documented,but we discuss the possibility that the high outbreak synchrony in geographically separated populations of BPH may suggest a “Moran effect” such as climate that promotes an environment favoring above-average increases in BPH populations. Also, we hypothesize that BPH functions as a metapopulation and, as such, periodic outbreaks could be a natural phenomenon requiring resupply of planthoppers into vacant areas to ensure genetic linkage among subpopulations. We conclude with a series of recommendations for research and policy changes aimed at better understanding the cause of BPH outbreaks and for developing sustainable management practices to prevent future outbreaks.

Epidemiological characteristics of varicella outbreaks in the Republic of Korea, 2016–2020

Eun-Young Kim,Chungmin Park,Gyehee Lee,Suyeon Jeong,Jeongsuk Song,Dong-Han Lee 질병관리본부 2022 Osong Public Health and Research Persptectives Vol.13 No.2

Objectives: We described the trends and epidemiological characteristics of varicella outbreaks from 2016 to 2020 in the Republic of Korea. Methods: We investigated variables such as the outbreak setting, age of patients, vaccination status, and lesion count. The collected data were analyzed with the Cochrane-Armitage trend test and Kruskal-Wallis test. These statistical tests were performed using R ver. 4.0.3. Results: The number of varicella outbreaks increased from 2016 to 2018; however, after a slight decrease in the number of outbreaks in 2019, the number fell sharply in 2020. The median size of outbreaks decreased from 8 to 9 cases during 2016−2019 to 6 cases in 2020. The median duration of outbreaks was 18 days during 2016−2017, 28 days in 2018, 29 days in 2019, and 15 days in 2020. Varicella outbreaks occurred most frequently in elementary schools, and vaccination coverage of patients increased from 89.4% in 2016 to 97.2% in 2019. The median age of patients with outbreak-related varicella decreased from 8 years in 2016 to 6 years in 2020. Conclusion: Significant changes were observed in the age of patients with outbreak-related varicella. Ongoing monitoring of varicella outbreaks should be conducted. Further research will be needed to measure the disease burden of varicella and enable evidence-based policy decisions.

유행관리 프로토콜을 적용한 소아병동의 노로바이러스 유행관리

김은옥,박현애 대한의료관련감염관리학회 2022 의료관련감염관리 Vol.27 No.1

A norovirus outbreak management protocol was implemented in a tertiary care hospital in Seoul, South Korea. This was to prevent outbreaks of and the spread of the virus in the pediatric wards of the hospital. We compared the number of outbreaks, duration of outbreaks or clusters, and number of nosocomial transmissions before (Period 1) and after the protocol was implemented (Period 2). A total of 3 norovirus outbreaks occurred during Period 1, and there were 4 cluster cases but no outbreaks during Period 2, due to adequate management in the preoutbreak stage. The duration of prevalence or cluster management decreased from a median of 33 days (IQR, 30-36) in the Period 1 to a median of 14.5 days (IQR, 12.5-19) in Period 2 (P=0.057). The proportion of cases from nosocomial transmission among the total number of cases within an outbreak or cluster period significantly decreased from 65.2% (15/23 cases) in Period 1 to 0% (0/16 cases) in Period 2 (P=0.001). With the implementation of the protocol, early detection of the epidemic and immediate interventions were possible. It was therefore possible to prevent nosocomial norovirus outbreaks.

코로나바이러스감염증-19 유행이 감염병 전담병원 근무자에게 미치는 영향: 감정 변화와 스트레스의 직종 간 비교

엽주용,박진형,박현경,표창해,박근홍,김한범,함은미,이유성 대한응급의학회 2021 대한응급의학회지 Vol.32 No.2

Objective: The coronavirus disease 2019 (COVID-19) outbreak is currently ravaging the world and is a major threat to public health. Healthcare workers (HCWs) are at a high risk of acquiring and transmitting COVID-19. Hence, HCWs are also experiencing emotional and behavioral changes. The purpose of this study was to compare emotional changes and stress between occupations and to investigate the impact of emotions of HCWs during the COVID-19 outbreak. Methods: An anonymous, self-administered, previously validated questionnaire was given to HCWs at a hospital dedicated to infectious diseases in Korea during the COVID-19 outbreak. The participants were asked to evaluate stress factors, depressive moods, trauma, reasons for continuing to work, things that helped them work, coping strategies to reduce stress, motivators that could help them work during future outbreaks, and what they would like to do after the outbreak was over. Results: The total number of participants was 400. The average age of participants was 34.69±9.44. Stress and depressive moods showed variations in the job-to-job comparisons. Ethical duty and the professionalism of the HCWs pushed them to continue with their jobs. The news of a decline in the number of patients was helpful to HCWs. The implementation of personal hygiene programs helped in reducing stress. The provision of adequate personal protective equipment was a factor that would encourage them to work during any future outbreak. The participants wanted to go on a trip after the outbreak was over. Conclusion: Our findings indicate that the COVID-19 outbreak had a significant emotional impact on HCWs. The concerns of HCWs may affect their work efficiency in an outbreak and should be addressed by incorporating appropriate management strategies while planning to combat an outbreak.

A cholera outbreak in Alborz Province, Iran: a matched case-control study

Ghobad Moradi,Mohammad Aziz Rasouli,Parvin Mohammadi,Elham Elahi,Hojatollah Barati 한국역학회 2016 Epidemiology and Health Vol.38 No.-

OBJECTIVES: A total of 229 confirmed cholera cases were reported in Alborz Province during an outbreak that lasted from June 2011 to August 2011. This study aimed to identify potential sources of transmission in order to determine suitable interventions in similar outbreaks. In other words, the lessons learned from this retrospective study can be utilized to manage future similar outbreaks. METHODS: An age-matched and sex-matched case-control study was conducted during the outbreak. For each case, two control subjects were selected from the neighborhood. A case of cholera was defined as a bacteriologically confirmed case with signs and symptoms of cholera. This study was conducted from June 14, 2011 through August 23, 2011. The data were analyzed by calculating odds ratios (ORs) using the logistic regression method. RESULTS: In this outbreak, 229 confirmed cholera cases were diagnosed. The following risk factors were found to be associated with cholera: consumption of unrefrigerated leftover food (OR, 3.05; 95% confidence interval [CI], 1.72 to 5.41), consumption of vegetables and fruits in the previous three days (OR, 2.75; 95% CI, 1.95 to 3.89), and a history of traveling in the previous five days (OR, 5.31; 95% CI, 2.21 to 9.72). CONCLUSIONS: Consumption of vegetables and fruits has remained an unresolved risk factor in cholera outbreaks in Iran in recent years. In order to reduce the risk of cholera, sanitary standards for fruits and vegetables should be observed at all points from production to consumption, the population should be educated regarding hygienic food storage during outbreaks, and sanitary standards should be maintained when traveling during cholera outbreaks.

Molecular Epidemiologic Study of a Methicillin-resistant Staphylococcus aureus Outbreak at a Newborn Nursery and Neonatal Intensive Care Unit

( Hyun Mi Kang ),( Ki Cheol Park ),( Kyung-yil Lee ),( Joonhong Park ),( Sun Hee Park ),( Dong-gun Lee ),( Jong-hyun Kim ) 대한소아감염학회 2019 Pediatric Infection and Vaccine Vol.26 No.3

목적: 본 연구에서는 신생아실과 신생아 중환자실에서 발생한 methicillin-resistant Staphylococcus aureus (MRSA) 유행에서 환자와 보균자에서 분리된 MRSA의 분자역학적 연관성을 조사하여 유행의 감염원과 전파경로를 파악하고자 하였다. 방법: MRSA 유행기간인 2017년 8월부터 9월까지 피부감염 및 패혈증 환자들과 보균자로부터 분리된 MRSA 균주를 대상으로 유전형 및 병원성 인자를 분석하고 항생제 감수성 결과를 수집하였다. 결과: 연구기간 동안 신생아실(n=27)과 신생아 중환자실(n=14)에 총 41명의 신생아들이 입원하였다. 그 중, 7명(피부감염[n=6], 패혈증[n=1])에서 MRSA 감염이 확진되었고, 보균자 4명이 발견되었다. 신생아와 접촉이 있는 의료진 32명 중 3명이 MRSA를 비강에 보균하였다. 피부감염 유행 원인 균주는 Staphylococcal chromosomal cassette mec (SCCmec) type II, sequence type (ST) 89, spa type t375였고, 뮤피로신 저농도 내성을 포함하여 항생제 다제내성을 보였다. 패혈증을 일으킨 균주는 SCCmec type IVa, ST 72, 새로운 spa type인 t17879였다. 신생아 4명에게 집락된 MRSA 균주들은 다양하였으나 SCCmec type IVa, ST 72, spa type t664가 의료진과 신생아 2명에서 공통적으로 분리되었다. Panton-Valentine leukocidin (PVL) toxin 유전자가 신생아에게 집락된 모든 균주에서 발견되었다. 결론: 피부감염 유행을 일으킨 MRSA 균주는 항생제 다제내성을 보이는 균주였다. 신생아 MRSA 보균자에게서 분리된 균주는 모두 PVL 독소 유전자를 보유하였다. 유행기간 동안 다양한 MRSA 균주가 신생아들에게서 분리되기 때문에, 효과적인 감염 관리 및 추가 환자발생의 차단을 위하여 분자역학조사를 통하여 원인균을 확인하고 전파경로를 파악하는 것이 중요하다. Purpose: This study aimed to investigate the molecular epidemiology of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak at a newborn nursery and neonatal intensive care unit (NICU). Methods: During the outbreak, from August to September 2017, MRSA isolates collected from neonates and medical staff underwent genotyping and screened for virulence factors. Antibiotic susceptibilities were tested. Results: During the study period, 41 neonates were admitted at the nursery (n=27) and NICU (n=14). Of these, 7 had MRSA infections (skin infection [n=6] and sepsis [n=1]) and 4 were colonized with MRSA. Associated medical staff (n=32) were screened; three were nasal MRSA carriers. Staphylococcal chromosomal cassette mec (SCCmec) type II, sequence type (ST) 89, spa type t375 was found to be the skin infection outbreak causing strain, with multi-drug resistance including low-level mupirocin resistance. SCCmec type IVa, ST 72, and a novel spa type designated t17879, was the cause of MRSA sepsis. Many different types of MRSA were colonized on the neonates; however, SCCmec type IVa, ST 72, spa type t664 was colonized in both neonates and a NICU nurse. All MRSA isolates from colonized infants were positive for the Panton-Valentine leukocidin (PVL) toxin gene. Conclusions: The strain causing an outbreak of skin infections had multi-drug resistance. Also, MRSA colonized in the neonates were found to carry the PVL toxin gene. Because different strains are present during an outbreak, molecular epidemiologic studies are important to identify the outbreak strain and colonized strains which aid in effective control and prevention of future MRSA outbreaks.

Ongoing outbreak of human adenovirus-associated acute respiratory illness in the Republic of Korea military, 2013 to 2018

( Jae-hoon Ko ),( Hyeong-taek Woo ),( Hong Sang Oh ),( Song Mi Moon ),( Joon Young Choi ),( Jeong Uk Lim ),( Donghoon Kim ),( Junsu Byun ),( Soon-hwan Kwon ),( Daeyoun Kang ),( Jung Yeon Heo ),( Kyong 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.1

Background/Aims: Human adenovirus type 55 (HAdV-55), an emerging epidemic strain, has caused several large outbreaks in the Korean military since 2014, and HAdV-associated acute respiratory illness (HAdV-ARI) has been continuously reported thereafter. Methods: To evaluate the epidemiologic characteristics of HAdV-ARI in the Korean military, we analyzed respiratory virus polymerase chain reaction (RV-PCR) results, pneumonia surveillance results, and severe HAdV cases from all 14 Korean military hospitals from January 2013 to May 2018 and compared these data with nationwide RV surveillance data for the civilian population. Results: A total of 14,630 RV-PCRs was performed at military hospitals. HAdV (45.4%) was the most frequently detected RV, followed by human rhinovirus (12.3%) and influenza virus (6.3%). The percentage of the military positive for HAdV was significantly greater than the percentage of civilians positive for HAdV throughout the study period, with a large outbreak occurring during the winter to spring of 2014 to 2015. The outbreak continued until the end of the study, and non-seasonal detections increased over time. The reported number of pneumonia patients also increased during the outbreak. Case fatality rate was 0.075% overall but 15.6% in patients with respiratory failure. The proportion of severe patients did not change significantly during the study period. Conclusions: A large HAdV outbreak is currently ongoing in the Korean military, with a trend away from seasonality, and HAdV-55 is likely the predominant strain. Persistent efforts to control the outbreak, HAdV type-specific surveillance, and vaccine development are required.