Isolation due to the management of infectious diseases is thought to affect mental health, but the effects are still unknown. We examined the prevalence of anxiety symptoms and anger in persons isolated during the Middle East Respiratory Syndrome (MERS) epidemic both at isolation period and at four to six months after release from isolation. We also determined risk factors associated with these symptoms at four to six months. Of 14,992 individuals isolated for 2-week due to having contact with MERS patients in 2015, when MERS was introduced to Korea, 1,692 individuals were included in this study. Anxiety symptoms were evaluated with the Generalized Anxiety Disorder 7-item scale and anger was assessed with the State-Trait Anger Expression Inventory at four to six months after release from isolation for MERS. Of 1,692 who came in contact with MERS patients, 1,656 were not diagnosed with MERS. Among 1,656, anxiety symptoms showed 7.6% (95% confidence interval [CI], 6.3 to 8.9%) and feelings of anger were present in 16.6% (95% CI, 14.8 to 18.4%) during the isolation period. At four to six months after release from isolation, anxiety symptoms were observed in 3.0% (95%CI, 2.2 to 3.9%). Feelings of anger were present in 6.4% (95% CI, 5.2 to 7.6%). Risk factors for experiencing anxiety symptoms and anger at four to six months after release included symptoms related to MERS during isolation, inadequate supplies (food, clothes, accommodation), social networking activities (email, text, Internet), history of psychiatric illnesses, and financial loss. Mental health problems at four to six month after release from isolation might be prevented by providing mental health support to individuals with vulnerable mental health, and providing accurate information as well as appropriate supplies, including food, clothes, and accommodation.

In about 20 days since the diagnosis of the first case of the 2019 novel coronavirus (2019-nCoV) in Korea on January 20, 2020, 28 cases have been confirmed. Fifteen patients (53.6%) of them were male and median age of was 42 years (range, 20-73). Of the confirmed cases, 16, 9, and 3 were index (57.2%), first-generation (32.1%), and second-generation (10.7%) cases, respectively. All first-generation and second-generation patients were family members or intimate acquaintances of the index cases with close contacts. Fifteen among 16 index patients had entered Korea from January 19 to 24, 2020 while 1 patient had entered Korea on January 31, 2020. The average incubation period was 3.9 days (median, 3.0), and the reproduction number was estimated as 0.48. Three of the confirmed patients were asymptomatic when they were diagnosed. Epidemiological indicators will be revised with the availability of additional data in the future. Sharing epidemiological information among researchers worldwide is essential for efficient preparation and response in tackling this new infectious disease.

The distinct characteristic of the Middle East Respiratory Syndrome (MERS) outbreak in South Korea is that it not only involves intra-hospital transmission, but it also involves hospital-to-hospital transmission. It has been the largest MERS outbreak outside the Middle East, with 186 confirmed cases and, among them, 36 fatal cases as of July 26, 2015. All confirmed cases are suspected to be hospital-acquired infections except one case of household transmission and two cases still undergoing examination. The Korean health care system has been the major factor shaping the unique characteristics of the outbreak. Taking this as an opportunity, the Korean government should carefully assess the fundamental problems of the vulnerability to hospital infection and make short- as well as long-term plans for countermeasures. In addition, it is hoped that this journal, Epidemiology and Health, becomes a place where various topics regarding MERS can be discussed and shared.

OBJECTIVES: Since the first novel coronavirus disease 2019 (COVID-19) patient in Korea was diagnosed on January 20, 2020, 30 patients were diagnosed until February 17, 2020. However, 5,298 additional patients were confirmed until March 4, 2020. Therefore, our objective was to estimate the reproduction number (R) and evaluate the effectiveness of preventive measures.METHODS: A COVID-19 transmission model (SEIHR) was established to suit the Korean outbreak. The number of daily confirmed cases in Daegu and North Gyeongsang Province (NGP), the main area of outbreak, was used. The first patient’ symptom onset date in the Daegu/NGP outbreak was assumed as January 22, 2020. The R according to the start date of the effect of preventive measures was estimated.RESULTS: The estimated R in Hubei Province, China, was 4.0281, whereas the estimated initial R in Korea was 0.555, but later in Daegu/NGP, the value was between 3.472 and 3.543. When the transmission period decreases from 4-day to 2-day, the outbreak ends early, but the peak of the epidemic increases, and the total number of patients does not change greatly. It was found that, if transmission rate decreases, the outbreak ends early, and the size of the peak and the total number of patients also decreases.CONCLUSIONS: To end the COVID-19 epidemic, efforts to reduce the spread of the virus, such as social distancing and wearing masks, are absolutely crucial with the participation of the public, along with the policy of reducing the transmission period by finding and isolating patients as quickly as possible through the efforts of the quarantine authorities.

Acute pyelonephritis causes significant morbidity, tends to recur, and can be fatal; however, little is known regarding its epidemiology. In this paper, the authors describe the epidemiology of acute pyelonephritis in South Korea by using nationwide heath insurance claims data from 1997 to 1999. The National Health Insurance System of South Korea covers almost the entire population (99%). The overall average annual incidence rate of pyelonephritis in 1997–1999 was 35.7 per 10,000 population (male, 12.6; female, 59.0). Approximately one of every seven patients was hospitalized (incidence per 10,000: inpatients, 5.5; outpatients, 30.1). Incidence varied with age and was higher in the summer season. Following an initial episode, the risk of a second episode within 12 months was 9.2% for females and 5.7% for males; by contrast, the risk of a fifth episode within a year following a fourth episode was 50.0% for females and 53.0% for males. Female sex (hazard ratio = 1.89, 95% confidence interval: 1.60, 2.23), advancing age, outpatient treatments (hazard ratio = 1.35, 95% confidence interval: 1.14, 1.60), and medical aid (hazard ratio = 1.23, 95% confidence interval: 1.08, 1.40) increased the risk of any recurrence. Pyelonephritis has a clear seasonal pattern and high rate of recurrence. The incidence of hospitalization for pyelonephritis in South Korea is similar to that in the United States and Canada.