Comparison of lifestyle, cognitive function, mental health, and quality of life between hospitalized older adults with COVID-19 and non-COVID-19 in South Korea: a cross-sectional study.

BACKGROUND: The coronavirus disease (COVID-19) pandemic has greatly impacted older adults, resulting in many deaths. The impact of lifestyle and mental health on vulnerable groups, such as older adults, can be large and long lasting. Therefore, this study aimed to investigate the effects of COVID-19 confirmation on cognition, lifestyle, mental health, and quality of life in adults aged 55 years. METHODS: The sample consisted of 111 people in the COVID group and 189 people in the non-COVID group aged over 55 years in South Korea. An online survey was conducted between January and May 2022. Participants responded to the following assessment tools: Yonsei Lifestyle Profile, Prospective and Retrospective Memory (PRMQ), Subjective Memory Complaints Questionnaire (SMCQ), Visual Analogue Scale, Patient Health Questionnaire-9 (PHQ-9), Insomnia Severity Index (ISI), Fear of COVID-19 Scale (FCV-19 S), and the World Health Organization Quality of Life Scale abbreviated version (WHOQOL-BREF). Differences in lifestyle, cognition, depression, anxiety, and quality of life were compared between the two groups. RESULTS: There were significant differences in physical activity, diet, the total score of the PRMQ, PM (a sub-score of the PRMQ), PHQ-9, Korean version of the ISI (ISI-K), and WHOQOL-BREF scores between the COVID and non-COVID groups. However, there were no significant differences in activity participation, Self-Rating Anxiety Scale (SAS), or FCV-19 S between groups. CONCLUSIONS: The study confirms that COVID-19 negatively affects memory, physical activity, diet, quality of life, depression, and insomnia in the older adults. Therefore, this study implicated that prevention and intervention strategies required improving the memory, lifestyle, and mental health of older adults with COVID-19. TRIAL REGISTRATION: The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board of Yonsei university in Korea (Registration number: 1041849-202112-SB-226-03, Date of registration: 01042022).

Timosaponin A3 Induces Anti-Obesity and Anti-Diabetic Effects In Vitro and In Vivo.

Obesity is a serious global health challenge, closely associated with numerous chronic conditions including type 2 diabetes. Anemarrhena asphodeloides Bunge (AA) known as Jimo has been used to address conditions associated with pathogenic heat such as wasting-thirst in Korean Medicine. Timosaponin A3 (TA3), a natural compound extracted from AA, has demonstrated potential therapeutic effects in various disease models. However, its effects on diabetes and obesity remain largely unexplored. We investigated the anti-obesity and anti-diabetic properties of TA3 using in vitro and in vivo models. TA3 treatment in NCI-H716 cells stimulated the secretion of glucagon-like peptide 1 (GLP-1) through the activation of phosphorylation of protein kinase A catalytic subunit (PKAc) and 5'-AMP-activated protein kinase (AMPK). In 3T3-L1 adipocytes, TA3 effectively inhibited lipid accumulation by regulating adipogenesis and lipogenesis. In a high-fat diet (HFD)-induced mice model, TA3 administration significantly reduced body weight gain and food intake. Furthermore, TA3 improved glucose tolerance, lipid profiles, and mitigated hepatic steatosis in HFD-fed mice. Histological analysis revealed that TA3 reduced the size of white adipocytes and inhibited adipose tissue generation. Notably, TA3 downregulated the expression of lipogenic factor, including fatty-acid synthase (FAS) and sterol regulatory element-binding protein 1c (SREBP1c), emphasizing its potential as an anti-obesity agent. These findings revealed that TA3 may be efficiently used as a natural compound for tackling obesity, diabetes, and associated metabolic disorders, providing a novel approach for therapeutic intervention.

Application of a cognitive program with a comprehensive strategy feedback for Korean older adults.

This study assesses the effect of a cognitive program with a comprehensive strategy feedback on the cognitive function and memory self-efficacy of community-dwelling older adults and explores its applicability in Korea. The study employed a group pre-posttest design on 10 cognitively normal older participants. The four-week cognitive program involved daily completion of cognitive tasks at home using CoTras-Pro 2 and remotely provided individual non-face-to-face feedback. Additionally, biweekly face-to-face group feedback sessions were conducted with five participants. The Korean version of the Montreal Cognitive Assessment, the Korean-Color Word Stroop Test, and the Memory Self-Efficacy Questionnaire were used. Post-interviews were conducted to collect feedback. The program exerted a notable positive impact on cognitive function and memory self-efficacy. A study designed as a large-scale program conducted in collaboration with community-based public and private organizations holds the potential to be modeled for similar intervention programs involving a large number of participants.

Current Status of Q Fever and the Challenge of Outbreak Preparedness in Korea: One Health Approach to Zoonoses.

Human Q fever, a zoonosis caused by Coxiella burnetii, presents with diverse clinical manifestations ranging from mild self-limited febrile illnesses to life-threatening complications such as endocarditis or vascular infection. Although acute Q fever is a benign illness with a low mortality rate, a large-scale outbreak of Q fever in the Netherlands led to concerns about the possibility of blood transfusion-related transmission or obstetric complications in pregnant women. Furthermore, a small minority (< 5%) of patients with asymptomatic or symptomatic infection progress to chronic Q fever. Chronic Q fever is fatal in 5-50% of patients if left untreated. In South Korea, Q fever in humans was designated as a notifiable infectious disease in 2006, and the number of Q fever cases has increased sharply since 2015. Nonetheless, it is still considered a neglected and under-recognized infectious disease. In this review, recent trends of human and animal Q fever in South Korea, and public health concerns regarding Q fever outbreaks are reviewed, and we consider how a One Health approach could be applied as a preventive measure to prepare for zoonotic Q fever outbreaks.

COVID-19 Outbreak and Presymptomatic Transmission in Pilgrim Travelers Who Returned to Korea from Israel.

BACKGROUND: On February 21, 2020, 2 coronavirus disease 2019 (COVID-19) cases in pilgrim travelers from Korea to Israel were identified. We investigated the source of infection, clinical features of COVID-19, and transmission potential of presymptomatic and asymptomatic cases. METHODS: All 39 pilgrim travelers were aggressively tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Their clinical features and possible source of infection were investigated by interview and review of their medical records. Ten confirmed cases without symptoms at the first sampling dates were selected for follow-up reverse transcription polymerase chain reaction tests. RESULTS: Of 39 pilgrim travelers, 30 (77%) were positive for SARS-CoV-2. Among the 30 positive COVID-19 cases, 4 (13%) were asymptomatic. Available follow-up cycle threshold values from 10 cases gradually increased over time and were lower during the presymptomatic period than during the postsymptomatic period. Out of 328 contacts related to the COVID-19 cases in the pilgrim travelers, 22 additional cases (7%) were confirmed with SARS-CoV-2 infections. Three tertiary cases were identified to be transmitted by presymptomatic secondary cases. CONCLUSION: To prevent transmission of COVID-19, we need to focus on presymptomatic and asymptomatic cases, and massive testing for SARS-CoV-2 is required. More research about the possibility of presymptomatic transmission over 2 days before symptom onset is required.

The Effect of Occupation-Based Bilateral Upper Extremity Training in a Medical Setting for Stroke Patients: A Single-Blinded, Pilot Randomized Controlled Trial.

BACKGROUND: Occupation used in occupation-based intervention requires the use of 2 naturally coordinated hands. OBJECTIVE: To investigate by implementing occupation-based bilateral upper extremity training in medical setting to stroke patients and determine its effect in patients' bilateral upper extremity function recovery. METHODS: A total of 20 patients were randomly assigned to the experimental group (occupation-based bilateral upper extremity training) or control group (task-based bilateral upper extremity training). The intervention of the 2 groups was conducted 30 minutes a day, 5 times a week, and 4 weeks long. The outcome was assessed using the Canadian Occupational Performance Measure, Stroke Impact Scale, Action Research Arm Test, the Yonsei-Bilateral Activity Test, Accelerometer, and participants were assessed at baseline and after 4 weeks. RESULTS: There was a significant change in the satisfaction and performance status of occupational performance, strength, Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL), emotion, participant recovery in stroke recovery, gross movement in the function of the affected side, satisfaction in perform bilateral upper extremity in the experimental group compared to the control group. CONCLUSIONS: The clinical significance of this study is that this study demonstrated the effectiveness and usefulness of the training in the actual medical setting in improving upper extremity function and psychosocial factors.

Validity of a novel computerized screening test system for mild cognitive impairment.

ABSTRACTBackground:The mobile screening test system for screening mild cognitive impairment (mSTS-MCI) was developed for clinical use. However, the clinical usefulness of mSTS-MCI to detect elderly with MCI from those who are cognitively healthy has yet to be validated. Moreover, the comparability between this system and traditional screening tests for MCI has not been evaluated. OBJECTIVE: The purpose of this study was to examine the validity and reliability of the mSTS-MCI and confirm the cut-off scores to detect MCI. METHOD: The data were collected from 107 healthy elderly people and 74 elderly people with MCI. Concurrent validity was examined using the Korean version of Montreal Cognitive Assessment (MoCA-K) as a gold standard test, and test-retest reliability was investigated using 30 of the study participants at four-week intervals. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were confirmed through Receiver Operating Characteristic (ROC) analysis, and the cut-off scores for elderly people with MCI were identified. RESULTS: Concurrent validity showed statistically significant correlations between the mSTS-MCI and MoCA-K and test-rests reliability indicated high correlation. As a result of screening predictability, the mSTS-MCI had a higher NPV than the MoCA-K. CONCLUSIONS: The mSTS-MCI was identified as a system with a high degree of validity and reliability. In addition, the mSTS-MCI showed high screening predictability, indicating it can be used in the clinical field as a screening test system for mild cognitive impairment.

Does cognition-specific computer training have better clinical outcomes than non-specific computer training? A single-blind, randomized controlled trial.

OBJECTIVE: The purpose of this study was to investigate differences between non-specific computer training (NCT) and cognition-specific computer training (CCT). DESIGN: Randomized controlled experimental study. SETTING: Local community welfare center. SUBJECTS: A total of 78 subjects with mild cognitive impairment (MCI) were randomly assigned to the NCT ( n = 39) or CCT group ( n = 39). INTERVENTION: The NCT group underwent NCT using Nintendo Wii for improving functional performance, while the CCT group underwent CCT using CoTras for improving function of the cognitive domain specifically. Subjects in both groups received 30-minute intervention three times a week for 10 weeks. MAIN MEASURES: To identify effects on cognitive function, the Wechsler Adult Intelligence Scale (WAIS) digit span subtests, Rey Auditory Verbal Learning Test (RAVLT), Trail Making Test-Part B (TMT-B), Rey-Osterrieth Complex Figure Test, and Modified Taylor Complex Figure (MTCF) were used. Health-related quality of life (HRQoL) was assessed using the Short-Form 36-item questionnaire. RESULTS: After 10 weeks, the WAIS subtests (digit span forward: 0.48 ± 0.08 vs. 0.12 ± 0.04; digit span backward: 0.46 ± 0.09 vs. 0.11 ± 0.04) and HRQoL (vitality: 9.05 ± 1.17 vs. 2.69 ± 1.67; role-emotional: 8.31 ± 1.20 vs. 4.15 ± 0.71; mental health: 11.62 ± 1.63 vs. 6.95 ± 1.75; bodily pain: 4.21 ± 2.17 vs. 0.10 ± 0.38) were significantly higher in the NCT group ( P < 0.05). CONCLUSION: NCT was superior to CCT for improving cognitive function and HRQoL of elderly adults with MCI.

Serologic Survey and Risk Factors for Coxiella burnetii Infection among Dairy Cattle Farmers in Korea.

BACKGROUND: The zoonotic disease Q fever is caused by Coxiella burnetii and usually affects high-risk human populations. We conducted a serological survey of dairy cattle farmers in Korea to determine seroreactivity and identify risk factors for C. burnetii infection. METHODS: This cross-sectional study included 1,824 of 7,219 dairy cattle farms (25.3%) in the study region. The selected dairy cattle farmers visited the nearest public health centers or branches with completed questionnaires. Serum samples from the farmers were tested using an indirect immunofluorescence assay to detect phase II C. burnetii immunoglobulin (Ig) G or M antibodies. RESULTS: A total of 1,222 dairy cattle farmers from 784 dairy cattle farms (43.0%) participated in this study, and 11.0% (134/1,222) exhibited seroreactivity, defined as a phase II antigen IgG or IgM titer ≥ 1:16. In the multivariate analysis, male sex, residence in Gyeonggi Province, a larger herd size, and ocular/oral contact with birth products during calf delivery were significantly associated with a higher risk of C. burnetii infection. Furthermore, the risk was significantly lower among farmers who always wore protective gloves while cleaning cattle excretion, compared to those who sometimes or rarely wore protective gloves. CONCLUSION: Dairy cattle farmers should exercise caution by avoiding ocular/oral contact with birth products during calf delivery and by using protective equipment (including gloves).

Association among Work-Related Musculoskeletal Disorders, Job Stress, and Job Attitude of Occupational Therapists.

This study was conducted to investigate the associations among work-related musculoskeletal disorders (WMSDs), job stress, and job attitude of occupational therapists in South Korea. Self-reporting questionnaires were distributed to 150 occupational therapists. Of the 128 occupational therapists who responded, 110 (85.9%) reported WMSDs affecting at least one body site. The most affected WMSDs site was the low back (26.8%), and the most reported number of body site affected by WMSDs was one (53.9%). As a result, there were significant differences in job stress and job attitude depending on the age, work experience, working hour, presence or absence of WMSDs, and number of site of pain. Factors influencing job attitude included job stress, the presence or absence of WMSDs and duration of pain. The results showed that the occurrence of WMSDs in occupational therapists was associated with increased job stress and negative job attitude.

The effects of game-based virtual reality movement therapy plus mental practice on upper extremity function in chronic stroke patients with hemiparesis: a randomized controlled trial.

[Purpose] The purpose of this study was to investigate the effects of game-based virtual reality movement therapy plus mental practice on upper extremity function in chronic stroke patients with hemiparesis. [Subjects] The subjects were chronic stroke patients with hemiparesis. [Methods] Thirty subjects were randomly assigned to either the control group or experimental group. All subjects received 20 sessions (5 days in a week) of virtual reality movement therapy using the Nintendo Wii. In addition to Wii-based virtual reality movement therapy, experimental group subjects performed mental practice consisting of 5 minutes of relaxation, Wii games imagination, and normalization phases before the beginning of Wii games. To compare the two groups, the upper extremity subtest of the Fugl-Meyer Assessment, Box and Block Test, and quality of movement subscale of the Motor Activity Log were performed. [Results] Both groups showed statistically significant improvement in the Fugl-Meyer Assessment, Box and Block Test, and quality of the movement subscale of Motor Activity Log after the interventions. Also, there were significant differences in the Fugl-Meyer Assessment, Box and Block Test, and quality of movement subscale of the Motor Activity Log between the two groups. [Conclusion] Game-based virtual reality movement therapy alone may be helpful to improve functional recovery of the upper extremity, but the addition of MP produces a lager improvement.

Characteristics and Factors Associated with Death among Patients Hospitalized for Severe Fever with Thrombocytopenia Syndrome, South Korea, 2013.

In South Korea, nationwide surveillance for severe fever with thrombocytopenia syndrome (SFTS) began during 2013. Among 301 surveillance cases, 35 hospitalized case-patients in 25 areas were confirmed by using virologic testing, and 16 (46%) case-patients subsequently died. The SFTS cases occurred during May-November and peaked during June (9 cases, 26%). The incidence of SFTS was higher in the southern regions of South Korea. Age and neurologic symptoms, including decreased level of consciousness and slurred speech, were heavily associated with death; neurologic symptoms during the first week after disease onset were also associated with death. Although melena was common among patients who died, no other hemorrhagic manifestations were substantively more common among those who died. No effective treatments, including ribavirin, were identified. Expansion of SFTS surveillance to include the outpatient sector and development of an antibody test would enhance completeness of SFTS detection in South Korea.

Humidifier disinfectant-associated children's interstitial lung disease.

RATIONALE: Beginning in 2006, epidemics of a fatal lung injury of unknown cause in children were observed in Korea every spring. A recent study demonstrated that this type of children's interstitial lung disease (chILD) is associated with humidifier disinfectant use. OBJECTIVES: To determine the clinical characteristics of this type of chILD and to assess whether the nationwide suspension of humidifier disinfectant sales in the autumn of 2011 affected its incidence. METHODS: The clinical characteristics of suspected cases between 2006 and 2011 were determined by a nationwide retrospective study. The potential causal relationship with humidifier disinfectants was examined by a prospective surveillance study after humidifier disinfectant sales were suspended. MEASUREMENTS AND MAIN RESULTS: In total, 138 children were diagnosed with this type of chILD, which was characterized by rapid progression, high mortality, predominance in the spring season, and a familial tendency. The annual incidence increased in 2011 and then dropped to zero in 2012. The children were on average 30.4 months old. The most frequent symptoms at admission were cough and dyspnea. As the disease progressed, the typical complication was spontaneous air leak. Eighty children (58%) died. Two years after humidifier disinfectant-sale suspension, no more new cases were found. CONCLUSIONS: This study suggests that humidifier disinfectant inhalation causes an idiopathic type of chILD that is characterized by spontaneous air leak, rapid progression, lack of response to treatment, and high mortality. Further safety studies must be performed on common environmental compounds, particularly those that enter the human body by an unusual route.

Three gastroenteritis outbreaks in South Korea caused by the consumption of kimchi tainted by norovirus GI.4.

BACKGROUND: In April 2013, outbreaks of acute gastroenteritis were reported at three schools in Jeonju, South Korea. Epidemiological investigations were performed to characterize the outbreaks and implement appropriate control measures. MATERIALS AND METHODS: Retrospective cohort studies were performed at these schools. Stool and environmental samples were collected for bacterial and viral assessment. A food supplier of the schools, food company X, was inspected, and samples of cabbage kimchi and groundwater were tested for norovirus by real-time reverse-transcriptase polymerase chain reaction. The relatedness of the detected norovirus strains was evaluated by phylogenetic analysis. RESULTS: Of the 3347 questionnaires distributed, 631 (attack rate: 18.9%) met the case definition. Among the consumed food items, kimchi products (i.e., cabbage and fresh kimchi) were significantly associated with illness. The kimchi products were supplied by food company X. Among stool samples from 95 students and 34 food handlers at the 3 schools, 39 (41.1%) and 14 (41.2%) samples, respectively, were positive for norovirus. The samples of groundwater and cabbage kimchi at food company X were positive for norovirus. The predominant genotype of norovirus detected in the patient, groundwater, and cabbage kimchi samples, GI.4, shared high nucleotide identity. CONCLUSIONS: Kimchi products tainted with norovirus GI.4 from contaminated groundwater were linked to the acute gastroenteritis outbreaks. Therefore, kimchi manufacturers in South Korea should apply chlorine disinfection when using groundwater. Moreover, more stringent sanitation requirements and strict regulations for food companies are recommended.

Effects of mental practice with action observation training on occupational performance after stroke.

BACKGROUND: Studies on whether mental practice (MP) in patients with stroke using action observation training (AOT) is effective in improving physical performance are still insufficient. To examine the effects of MP on both occupational performance and motor function to complement studies relevant to MP with AOT. METHODS: Subjects of this study were 3 individuals who were diagnosed with stroke. We used an A-B-A study design with follow-up evaluation, which is a type of reversal single experimental research design. A total of 20 experimental sessions were conducted. To assess the long-term effect of MP with AOT, follow-up baseline measurements were made after 2 weeks without MP. Three-dimensional motion analysis and electromyography were conducted during each of the 20 sessions. The Motor Activity Log and Assessment of Motor and Process Skills were measured 3 times: in the pre-MP phase, the post-MP phase, and the 2-week follow-up phase. RESULTS: Occupational performance improved after intervention in all 3 subjects when applying an MP task using AOT. All subjects showed improvement of motor functions, including smoothness of movement, agonistic muscle activation, and co-ordination. The treatment effect continued after 2 weeks. CONCLUSIONS: MP using AOT in patients with stroke is an effective treatment protocol to improve occupational performance and motor function. Thus, MP using AOT may be applicable for treating stroke patients with stroke not only while they are in the hospital but also at home or in the community.

The effects of a Korean computer-based cognitive rehabilitation program on cognitive function and visual perception ability of patients with acute stroke.

[Purpose] The purpose of this study is to investigate the effects of a Korean computer-based cognitive rehabilitation program (CBCR) on the cognitive function and visual perception ability of patients with acute stroke. [Subjects] The subjects were 30 patients with acute stroke. [Methods] The subjects were randomly assigned to either the experimental group (EG) or the control group (CG). The EG subjects received CBCR with the CoTras program. The CG subjects received conventional cognitive rehabilitation. All subjects participated in a standard rehabilitation program according to a daily inpatient treatment schedule. In addition to standard rehabilitation, the subjects received 20 sessions (5 days a week for 4 weeks) of CBCR or conventional cognitive rehabilitation for 30 min. To compare the two groups, the Lowenstein Occupational Therapy Cognitive Assessment (LOTCA) and Motor-free Visual Perception Test-3 (MVPT-3) were performed. [Results] Both groups showed significant improvement in LOTCA and MVPT-3. Furthermore, there were significant differences in LOTCA and MVPT-3 between the two groups. [Conclusion] CBCR with CoTras may contribute toward the recovery of cognitive function and visual perception in patients with acute stroke.

A randomized controlled trial of the computer-based cognitive rehabilitation program for children (CoTras-C) to examine cognitive function and visual perception in children with developmental disabilities.

[Purpose] This study aimed to investigate the effects of a computer-based cognitive rehabilitation program for children with developmental disabilities. [Subjects] Subjects included 29 children with developmental disabilities. [Methods] The subjects were randomly allocated to either the experimental group or control group. Experimental group subjects received computer-based cognitive rehabilitation using the CoTras-C while control group subjects received conventional cognitive rehabilitation. All subjects received 20 sessions (2 days a week for 10 weeks) of the experimental or control intervention for 30 minutes. To compare the two groups, the Korean-Developmental Test of Visual Perception-2 and Kaufman Assessment Battery for Children were performed before and after the intervention. [Results] Both groups showed statistically significant improvement in their scores after intervention. Additionally, there were significant differences in the scores between the two groups. [Conclusion] The computer-based cognitive rehabilitation with CoTras-C may be helpful in improving the recovery of cognitive function and visual perception in children with developmental disabilities.

Sensitivity of the accelerometer as a measurement tool for upper extremity movement by stroke patients: a comparison with the action research arm test.

[Purpose] This study investigated the sensitivity of an accelerometer in a comparison with the Action Research Arm Test (ARAT). [Subjects] Fifteen stroke patients participated in this study. [Methods] Subjects wore accelerometers on both wrists and performed the ARAT items. We then compared the data measured by the accelerometer with that of the ARAT. [Results] ARAT scores were higher on the non-affected side than the affected side, while the amount of upper extremity movement was higher on the affected side. The correlation coefficients for the two tools were not significantly different. [Conclusion] Our findings indicate that an accelerometer is a useful and sensitive instrument for clinically measuring the upper extremity activity of patients with stroke.

A cluster of lung injury cases associated with home humidifier use: an epidemiological investigation.

BACKGROUND: In April 2011 a tertiary hospital in Seoul, Korea reported several cases of severe respiratory distress of unknown origin in young adults. METHODS: To find the route of transmission, causative agent and patient risk factors of the outbreak, an investigation of the epidemic was initiated. Clinicopathological conferences led to the suspicion that the cases related to an inhalation injury. An age- and sex-matched case-control study was therefore performed to examine the inhalation exposure of the patients to various agents. RESULTS: Of the 28 confirmed cases, 18 agreed to participate. A total of 121 age- and sex-matched controls with pulmonary, allergic or obstetric disease were selected. All patients and controls completed questionnaires with questions about exposure to various inhalants. The crude ORs for patient exposure to indoor mould, humidifier use, humidifier detergent use and insecticide use were 4.4 (95% CI 1.5 to 13.1), 13.7 (95% CI 1.8 to 106.3), 47.3 (95% CI 6.1 to 369.7) and 3.9 (95% CI 1.3 to 11.7), respectively. However, when considered concurrently, indoor mould and insecticide use lost statistical significance. Moreover, humidifier use was ruled out as the cause because of a lack of biological plausibility and the weak strength of the association. This suggested that humidifier disinfectant was the cause of the outbreak. This information led the Korean government to order the removal of humidifier detergents from the market. In the years following the ban, no additional cases were detected. CONCLUSIONS: Epidemiological evidence strongly suggests that the lung injury outbreak was caused by humidifier detergent use at home.

Diarrheal outbreak caused by atypical enteropathogenic Escherichia coli O157:H45 in South Korea.

UNLABELLED: Background: In May 2013, an outbreak of gastroenteritis occurred in a high school in Incheon, South Korea. We investigated the outbreak in order to identify the pathogen and mode of transmission. MATERIALS AND METHODS: A case-control study was performed using standardized questionnaires with a case definition of illness with diarrhea. Stool samples, environmental samples, and samples from preserved food items were collected to test pathogens. Pulsed-field gel electrophoresis (PFGE) was performed on the outbreak-related Escherichia coli strains. RESULTS: Thirty-three people (attack rate: 2.5%) met the case definition, and the pattern of the epidemic curve suggested a point-source outbreak. The common symptoms of cases were diarrhea (100.0%), abdominal pain (75.8%), chills (45.5%), and nausea (39.4%). Cases were found to be 8.26 times more likely to have eaten spicy fish soup with cod (95% confidence interval: 1.05-65.01). Consumption of egg soup with spring onions or braised eggs with razor clam flesh was significantly associated with illness. Atypical enteropathogenic E. coli O157:H45 was isolated from samples of 9 cases (27.3%) and tuna bibimbap. PFGE patterns of all tested isolates of O157 serotype were indistinguishable. CONCLUSIONS: This outbreak was caused by atypical enteropathogenic E. coli O157:H45 and the food vehicle was suspected to be tuna bibimbap. The statistical analysis was not in concordance with the microbiologic tests, probably owing to low pathogenicity of atypical enteropathogenic E. coli O157. This is the first report of an outbreak caused by atypical enteropathogenic E. coli O157.