Estimating the number of severe COVID-19 cases and COVID-19-related deaths averted by a nationwide vaccination campaign in Republic of Korea

Objectives@#The Korea Disease Control and Prevention Agency promotes vaccination by regularly providing information on its benefits for reducing the severity of coronavirus disease 2019 (COVID-19). This study aimed to analyze the number of averted severe COVID-19 cases and COVID-19-related deaths by age group and quantify the impact of Republic of Korea’s nationwide vaccination campaign. @*Methods@#We analyzed an integrated database from the beginning of the vaccination campaign on February 26, 2021 to October 15, 2022. We estimated the cumulative number of severe cases and COVID-19-related deaths over time by comparing observed and estimated cases among unvaccinated and vaccinated groups using statistical modeling. We compared daily age-adjusted rates of severe cases and deaths in the unvaccinated group to those in the vaccinated group and calculated the susceptible population and proportion of vaccinated people by age. @*Results@#There were 23,793 severe cases and 25,441 deaths related to COVID-19. We estimated that 119,579 (95% confidence interval [CI], 118,901–120,257) severe COVID-19 cases and 137,636 (95% CI, 136,909–138,363) COVID-19-related deaths would have occurred if vaccination had not been performed. Therefore, 95,786 (95% CI, 94,659–96,913) severe cases and 112,195 (95% CI, 110,870–113,520) deaths were prevented as a result of the vaccination campaign. @*Conclusion@#We found that, if the nationwide COVID-19 vaccination campaign had not been implemented, the number of severe cases and deaths would have been at least 4 times higher. These findings suggest that Republic of Korea’s nationwide vaccination campaign reduced the number of severe cases and COVID-19 deaths.

Change in Severity and Clinical Manifestation of MIS-C Over SARSCoV-2 Variant Outbreaks in Korea

Background@#There is difference in the incidence of multi-system inflammatory syndrome in children (MIS-C) in patients with different variants of severe acute respiratory syndrome coronavirus 2, however, little is known about the epidemiology in Asian countries. We investigated and compared the epidemiology of the MIS-C during omicron-dominant period with that of previous periods in South Korea. @*Methods@#We obtained clinical, epidemiological and laboratory data on MIS-C cases from national MIS-C surveillance in South Korea. We defined pre-delta period as January 2020–May 2021; delta period as June 2021–December 2021; and omicron period as January 2022–April 2022. We describe the clinical characteristics and outcomes of MIS-C patients by period. @*Results@#A total of 91 cases were assessed to be MIS-C cases. Number of MIS-C cases have increased from six cases during pre-delta period to 66 cases during omicron period, while the incidence rate (the number of MIS-C cases per 100,000 cases of reported coronavirus disease 2019) has decreased from 38.5 cases per 100,000 (95% confidence interval [CI], 14.1–83.9) during pre-delta period to 1.6 cases per 100,000 (95% CI, 1.2–2.0) during omicron periods. During pre-delta period, 66.7% and 100% had hypotension and gastrointestinal involvement, respectively; while during omicron period, 12.1% and 6.1% had such clinical manifestations. Fifty percent of pre-delta MIS-C patients were taken intensive care unit (ICU) cares, while 10.6% of patients during omicron periods were in ICUs. @*Conclusion@#Omicron period were associated with less severe clinical manifestation compared to pre-delta and delta periods. Although incidence rate of MIS-C was lower for the omicron period than pre-delta and delta periods, number of patients reported with MIS-C may pose a substantial clinical burden.

Vaccine Effectiveness Against Severe Disease and Death for Patients With COVID-19 During the Delta-Dominant and Omicron-Emerging Periods:A K-COVE Study

National cohort data collected during the coronavirus disease 2019 (COVID-19) delta and omicron periods in Korea revealed a lower risk of severe infection in recipients of three doses of the COVID-19 vaccine (adjusted odds ratio [aOR], 0.05–0.08). The risk of death was reduced during the omicron period compared to the delta period (aOR, 0.75; 95% confidence interval, 0.67–0.84).

Pediatric Deaths Associated With Coronavirus Disease 2019 (COVID-19) in Korea

As of September 3, 2022, 5,388,338 coronavirus disease 2019 (COVID-19) cases and 46 deaths (3 in 2021 and 43 in 2022) were reported in children ≤ 18 years in Korea. Cumulative confirmed cases accounted for 67.3% of the population aged ≤ 18 years and case fatality rate was 0.85/100,000. Among 46 fatal cases, 58.7% were male and median age was 7 years.Underlying diseases were present in 47.8%; neurologic diseases (63.6%) and malignancy (13.6%) most common. Only four had history of COVID-19 immunization. COVID-19 associated deaths occurred at median 2 days from diagnosis (range: −1 to 21). Among COVID-19 deaths, 41.3% occurred before admission; 2 before hospital arrival and 17 in the emergency department. Among children whose cause was documented, myocarditis, respiratory and multiorgan failure were most common. COVID-19 associated death was seen early after diagnosis in children and public health policies to provide access to medical care for children with COVID-19 are essential during the pandemic.

Application of Standardization for Causal Inference in Observational Studies: A Step-by-step Tutorial for Analysis Using R Software / 예방의학회지

Epidemiological studies typically examine the causal effect of exposure on a health outcome. Standardization is one of the most straightforward methods for estimating causal estimands. However, compared to inverse probability weighting, there is a lack of user-centric explanations for implementing standardization to estimate causal estimands. This paper explains the standardization method using basic R functions only and how it is linked to the R package stdReg, which can be used to implement the same procedure. We provide a step-by-step tutorial for estimating causal risk differences, causal risk ratios, and causal odds ratios based on standardization. We also discuss how to carry out subgroup analysis in detail.

Importation and Transmission of SARS-CoV-2 B.1.1.529 (Omicron) Variant of Concern in Korea, November 2021

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel.There may be more transmissions with this VOC in Korea than reported.

Comparison of influenza surveillance data from the Republic of Korea, selected northern hemisphere countries and Hong Kong SAR (China) from 2012 to 2017

@#Influenza surveillance is conducted in many countries; it is one of the most important types of infectious disease surveillance due to the significant impact and burden of the influenza virus. The Republic of Korea has a temperate climate, and influenza activity usually peaks in the winter as in other temperate-climate countries in the northern hemisphere. This descriptive study compared the influenza surveillance data from the Korea Centers for Disease Control and Prevention with that from other countries and areas in the northern hemisphere, namely China, including Hong Kong Special Administrative Region SAR, Japan and the United States of America, to identify seasonal influenza patterns from 2012 to 2017. Data on influenza-like illnesses (ILIs) and laboratory surveillance were collected from various sources; visual comparisons were conducted on the onset, duration and the peak timing of each influenza season based on subtypes. Correlation coefficients were estimated, and time differences for the beginning of influenza seasons between the Republic of Korea and other countries were measured. ILIs in North China and cases reported from Japan’s sentinel surveillance showed high correlations with the Republic of Korea. The number of confirmed influenza cases in Japan showed a high correlation with the laboratory-confirmed influenza cases in the Republic of Korea. We found that there are similarities in the influenza patterns of the Republic of Korea, Japan and North China. Monitoring these neighbouring countries’ data may be useful for understanding influenza patterns in the Republic of Korea. Continuous monitoring and comparison of influenza surveillance data with neighbouring countries is recommended to enhance preparedness against influenza.

Ischemic Stroke Caused by Spontaneous Subclavian Artery Dissection

No abstract available.

Congenital Nystagmus in Turner Syndrome

No abstract available.

Invasive Aspergillosis Complicated by Occlusion of Internal Carotid Artery and Cerebral Infarction

Invasive aspergillosis is one of rare causes of mortality for the immune-compromised patients. We present a case of invasive aspergillosis complicated by the occlusion of the internal carotid artery and cerebral infarction in a patient with diabetes mellitus. Although initial biopsy did not find the pathogen, the repeated attempts of sampling showed aspergillosis. Combination of surgical removal of necrotic tissue and voriconazole medication improved symptoms and reduced the burden of infection.

Hypoxic Brain Damage with Restricted Diffusion in the Splenium of Corpus Callosum

No abstract available.

Removal of Choledocholith by Endoscopic Retrograde Cholangiopancreatography in a Situs Invsersus Patient / 대한소화기학회지

Situs inversus is an extremely rare autosomal recessive disease with left-right inversion of internal organs. It carries technical difficulties in diagnostic or therapeutic procedures. There have been a few case reports on stone extraction by ERCP in situs inversus patients. ERCP techniques in situs inversus can be classified into conventional method and mirror image method. In mirror image method, the procedure is performed with the patient in the right lateral decubitus position and the endoscopist on the patient's left side. Until now, there is no consensus about which method is better. Herein, we report an unusual case of choledocholithiasis in a patient with situs inversus who underwent ERCP for stone extraction by both conventional method and mirror image method.

Antiviral Activity of Hederasaponin B from Hedera helix against Enterovirus 71 Subgenotypes C3 and C4a

Enterovirus 71 (EV71) is the predominant cause of hand, foot and mouth disease (HFMD). The antiviral activity of hederasaponin B from Hedera helix against EV71 subgenotypes C3 and C4a was evaluated in vero cells. In the current study, the antiviral activity of hederasaponin B against EV71 C3 and C4a was determined by cytopathic effect (CPE) reduction method and western blot assay. Our results demonstrated that hederasaponin B and 30% ethanol extract of Hedera helix containing hederasaponin B showed significant antiviral activity against EV71 subgenotypes C3 and C4a by reducing the formation of a visible CPE. Hederasaponin B also inhibited the viral VP2 protein expression, suggesting the inhibition of viral capsid protein synthesis.These results suggest that hederasaponin B and Hedera helix extract containing hederasaponin B can be novel drug candidates with broad-spectrum antiviral activity against various subgenotypes of EV71.

Antiviral Activity of Hederasaponin B from Hedera helix against Enterovirus 71 Subgenotypes C3 and C4a

Enterovirus 71 (EV71) is the predominant cause of hand, foot and mouth disease (HFMD). The antiviral activity of hederasaponin B from Hedera helix against EV71 subgenotypes C3 and C4a was evaluated in vero cells. In the current study, the antiviral activity of hederasaponin B against EV71 C3 and C4a was determined by cytopathic effect (CPE) reduction method and western blot assay. Our results demonstrated that hederasaponin B and 30% ethanol extract of Hedera helix containing hederasaponin B showed significant antiviral activity against EV71 subgenotypes C3 and C4a by reducing the formation of a visible CPE. Hederasaponin B also inhibited the viral VP2 protein expression, suggesting the inhibition of viral capsid protein synthesis.These results suggest that hederasaponin B and Hedera helix extract containing hederasaponin B can be novel drug candidates with broad-spectrum antiviral activity against various subgenotypes of EV71.

Erratum: Addition of a Co-Author

The authors regret that one co-author was missing in the article.

Epidemiological Characteristics of the First Water-Borne Outbreak of Cryptosporidiosis in Seoul, Korea

The first case of human cryptosporidiosis was reported in Korea in 1995; however, an outbreak of Cryptosporidium has not been reported in Korea until now. This paper describes the first outbreak of cryptosporidiosis in Korea. On May 24, 2012, a local public health center filed a report on 126 residents with gastrointestinal symptoms in an old apartment complex in Seoul. Epidemiological investigations were implemented on 125 of the 126 patients. The patients were reported continuously over a period of 22 days. Diarrhea was the most common clinical symptom, and lasted for 5 days on average. The tap water was the only common exposure of the patients. During the environmental investigation it was discovered that the water and septic tanks were situated closely and that the waste water pipes were corroded where they passed over the water pipes. Cryptosporidium parvum was detected in 3 of the 7 stool specimens by PCR-RFLP. A number of Cryptosporidium oocysts were also detected in the water specimens from the water tank. In conclusion, Cryptosporidium parvum was the key causal pathogen of this outbreak. It is presumed that the tap water was contaminated by a sewage leak from the aged pipelines.

A Case of Transfusion Transmitted Hepatitis A Virus Infection Identified Through a Lookback Study / 대한수혈학회지

Hepatitis A virus (HAV) is mostly transmitted by the oral-fecal route. However, rare cases of transmission via blood transfusion still exist. A retrospective study was designed to trace a case of transfusion transmitted HAV (TTHAV) infection through the Post Donation Infection (PDI) system in Korea in 2006. We report here on a case of TTHAV that was identified through a lookback study. A 35-year old woman received 6 units of packed red cell transfusion when undergoing Caesarian section in a hospital. Ten days later, she developed a high fever and sore throat. Anorexia and abdominal pain developed in 45 days after transfusion. She was diagnosed with acute tonsillitis at the hospital, and she was not aware of her HAV infection at that time. Then, a donor informed the blood center of his HAV infection 10 days after donation to request his blood be discarded. The recipients of the blood were traced and epidemiological studies lead to the patient, which prompted her serum to be collected and tested. Finally, TTHAV was identified for this patient with positive anti-HAV IgG/IgM results. This is the first case of TTHAV to be identified through the HAV lookback study in Korea.

Distraction Osteogenesis for Early Correction of Sagittal Craniosynostosis

Sagittal synostosis with related functional aspects of elevated ICP, hydrocephalus, mental retardation and visual abnormalities, or with multiple suture synostosis, surgical correction is imperative. But, craniofacial surgery may impose a threat to an infant or small child. The blood volume in these patients is small and a minor hemorrhage may induce proportionately greater blood loss, resulting in a greater stress to the patient's system. Mortality resulting from craniofacial surgery is uncommon, mostly from operative hemorrhage and infections. Releasing the stenosis and reshaping the cranial vault is the primary operative goal. Authors sought to minimize surgical stress on the child and attain control of cranial vault reshaping by gradual distraction osteogenesis in treating children with sagittal suture synostosis. Three sagittal synostosis patients, aged from 11 months to 3 years old were treated. One of the patients had multiple suture synostosis. Patient follow-up ranged from 3 months to 3 years. Biparietal bone flap was elevated and external distraction devices were inserted. Distraction rate varied from 0.5 to 1mm/day, without a latency period. After a consolidation period of 2-3weeks, the devices were removed. Functional aspects of ICP and mental retardation subsided post surgery. Radiological follow-up showed cessation of enhancement of bone deposition at the frontal and occipital sutures. Excellent aesthetic results were accounted for in all three of the patients. Application of distraction osteogenesis in correcting sagittal craniosynostosis is very effective; surgical stress on the patients is minimal and controlled cranial vault reshaping is possible.