A Silent Outbreak of Hepatitis E Virus (HEV) Infection or False-Positive Reaction of Anti-HEV IgM after COVID-19 Vaccination? Epidemiological Investigation of an Outbreak in a Korean Factory Complex in 2022.

Background/Aims: To investigate a reported outbreak of presumed hepatitis E virus (HEV) infection in a Korean food manufacturing facility and to explore the association between anti-HEV immunoglobulin M (IgM) positivity and coronavirus disease 2019 (COVID-19) infection or vaccination. Methods: Twenty-four cases of anti-HEV IgM positivity were reported among 646 workers at the facility in 2022. An epidemiological investigation was conducted, comprising HEV-RNA testing of blood and environmental samples, analysis of group meal records, and an association between anti-HEV IgM positivity and confirmed COVID-19 infection or vaccination. Results: All 24 patients were asymptomatic, with cases spread sporadically across the facility. HEV RNA was not detected in the serum or environmental samples. Four out of 340 meals (1.2%) showed a significantly higher proportion of anti-HEV positivity in each meal intake group than in the non-intake group on certain days. Although the cumulative rate of COVID-19 infection showed no difference, the anti-HEV IgM positive group showed significantly higher proportions of >2 doses of COVID-19 vaccination (83.3% vs 48.7%, p=0.021), vaccination within 90 days (45.8% vs 19.7%, p=0.008), and having the Moderna vaccine administered as the last vaccine (75.0% vs 14.5%, p<0.001) than those of the anti-HEV negative group. In four multivariable models, three or more COVID-19 vaccinations and the Moderna vaccine as the last vaccine were consistently associated with anti-HEV IgM positivity, while the specific day group meal intake was also a significant factor. Conclusions: This epidemiological investigation showed that anti-HEV IgM positivity may occur as a false-positive result related to COVID-vaccination over three times and use of the Moderna vaccine, although a portion of true HEV infection may not be excluded.

The first reported hepatitis E outbreak in a food manufacturing factory: Korea, 2022.

OBJECTIVES: On February 16, 2022, 12 cases of hepatitis E virus (HEV) infection were reported in a food manufacturing factory in Korea. The aim of this study was to identify additional cases and to determine the source of this HEV outbreak. METHODS: This study was an in-depth investigation of 12 HEV immunoglobulin M (IgM)-positive cases and their demographic, clinical, and epidemiological characteristics. On-site specimens were collected from the environment and from humans, and a follow-up investigation was conducted 2 to 3 months after the outbreak. RESULTS: Among 80 production workers in the factory, 12 (15.0%) had acute HEV infection, all of whom were asymptomatic. The follow-up investigation showed that 3 cases were HEV IgMpositive, while 6 were HEV IgG-positive. HEV genes were not detected in the HEV IgM-positive specimens. HEV genes were not detected in the food products or environmental specimens collected on-site. HEV was presumed to be the causative pathogen. However, it could not be confirmed that the source of infection was common consumption inside the factory. CONCLUSIONS: This was the first domestic case of an HEV infection outbreak in a food manufacturing factory in Korea. Our results provide information for the future control of outbreaks and for the preparation of measures to prevent domestic outbreaks of HEV infection.

Detecting mpox infection in the early epidemic: an epidemiologic investigation of the third and fourth cases in Korea.

OBJECTIVES: As few mpox cases have been reported in Korea, we aimed to identify the characteristics of mpox infection by describing our epidemiologic investigation of a woman patient (index patient, the third case in Korea) and a physician who was infected by a needlestick injury (the fourth case). METHODS: We conducted contact tracing and exposure risk evaluation through interviews with these 2 patients and their physicians and contacts, as well as field investigations at each facility visited by the patients during their symptomatic periods. We then classified contacts into 3 levels according to their exposure risk and managed them to minimize further transmission by recommending quarantine and vaccination for post-exposure prophylaxis and monitoring their symptoms. RESULTS: The index patient had sexual contact with a man foreigner during a trip to Dubai, which was considered the probable route of transmission. In total, 27 healthcare-associated contacts across 7 healthcare facilities and 9 community contacts were identified. These contacts were classified into high (7 contacts), medium (9 contacts), and low (20 contacts) exposure risk groups. One high-risk contact was identified as a secondary patient: a physician who was injured while collecting specimens from the index patient. CONCLUSIONS: The index patient visited several medical facilities due to progressive symptoms prior to isolation. Although the 2022 mpox epidemic mainly affected young men, especially men who have sex with men, physicians should also consider mpox transmission in the general population for the timely detection of mpox-infected patients.

Factors Affecting Smoking Cessation Success of Heavy Smokers Registered in the Intensive Care Smoking Cessation Camp (Data from the National Tobacco Control Center).

OBJECTIVES: The purpose of this study was to investigate the factors involved in the success of smoking cessation in heavy smokers enrolled in an intensive care smoking cessation camp program. METHODS: Heavy smokers enrolled in the program were classified into a success (n = 69) or failure (n = 29) group, according to whether they maintained smoking cessation for 6 months after the end of the program. Demographics, smoking behaviors, and smoking cessation-related characteristics were analyzed. RESULTS: Statistically significantly more participants in the success group had a spouse (98.6%; p = 0.008) compared with participants in the failure group (82.8%). However, multivariate logistic regression analysis indicated that having a spouse was not an independent factor in smoking cessation (p = 0.349). A significant difference in the frequency of counseling between the success and failure groups was observed (p = 0.001), with 72.5% of those who received counseling on 3-5 occasions for 6 months after the end of program successfully quit smoking, indicating that those who received more counseling had a higher likelihood of smoking cessation success. This was confirmed as an independent factor by multivariate logistic regression (p < 0.005). Furthermore, a graduate school level of education or higher, indicated a statistically greater success rate compared to those that were less well educated (p = 0.043). This was also observed as a significant independent factor using multivariate logistic regression (p = 0.046). CONCLUSION: Education level, marital status, and the number of counseling sessions were significant factors contributing to smoking cessation success.

Cardiovascular Disease Risk Factors and Obesity Levels in Korean Adults: Results from the Korea National Health and Nutrition Examination Survey, 2007-2015.

OBJECTIVES: The increase in the obesity rate in adult males in Korea is higher than countries in the Organization for Economic Co-operation and Development and other Asian countries. We examined the trends and prevalence of major risk factors for cardiovascular disease by evaluating the weight status amongst adults from 2007 to 2015. METHODS: The study included 37,402 adults, who participated in the Korea National Health and Nutrition Examination Survey. The prevalence trends of cardiovascular disease risk factors were estimated for each body mass index group. RESULTS: From 2007 to 2015, significant increases in the prevalence of hypertension, diabetes, and hypercholesterolemia were observed in normal weight adults (0.03 percentage point (%p), 0.06%p, and 0.13%p, respectively). Amongst the overweight and obese adults, a significant increase in the prevalence of hypercholesterolemia was observed, During this period, the prevalence of smoking decreased amongst obese adults and no significant changes in drinking habits and physical activity were noted across all body mass index groups. CONCLUSION: The prevalence of obesity in Korean adults is increasing, and it is necessary to implement interventions to prevent further weight gain and obesity-associated cardiovascular disease.