Sustained Vaccination Coverage during the Coronavirus Disease 2019 Epidemic in the Republic of Korea.

Amid the COVID-19 pandemic, vaccination coverage may decline due to limited accessibility to healthcare. We assessed the impact of the COVID-19 pandemic on vaccination coverage and the incidence of vaccine-preventable diseases (VPDs) in the Republic of Korea. National vaccination coverage of 10 essential vaccines administered to children between January-June 2019 and January-June 2020 was analyzed. The national incidence of selected VPDs was compared for the corresponding periods. During the COVID-19 outbreak, the vaccination rate in children aged 0-35 months in Korea did not decrease significantly, whereas the vaccination rate for children aged 4-6 years decreased by 1.4-1.9%. The overall incidence of VPDs decreased by 10-50% between 2019 and 2020, especially with varicella. Thus, the COVID-19 pandemic did not result in a decrease in vaccination coverage among Korean children, which prevented a surge in VPD incidence. Maintaining essential vaccination coverage without interruption is important during the response to the COVID-19 pandemic.

Outbreak of CTX-M-15-Producing Enterotoxigenic Escherichia coli O159:H20 in the Republic of Korea in 2016.

We investigated an outbreak of enterotoxigenic Escherichia coli (ETEC) O159:H20 associated with the consumption of a tossed-noodle dish in a high school in 2016. Thirty-three ETEC strains isolated from clinical and food samples were genetically indistinguishable. The outbreak strains were resistant to third-generation cephalosporins and harbored a blaCTX-M-15 gene on a 97-kb self-transferable IncK plasmid. This is the first outbreak caused by CTX-M-15-producing ETEC strains.

Are we investing wisely? A systematic analysis of nationally funded antimicrobial resistance projects in Republic of Korea, 2003-2013.

From 2003 to 2013, South Korea has conducted the National Antimicrobial Resistance Safety Control Program (NARSCP). The purpose of the current study was to systematically review national antimicrobial resistance (AMR) research trends and to provide guidance on future allocation of research funding to enable a comprehensive approach in AMR control. This study collected project reports related to AMR published by the Ministry of Food and Drug Safety, the Ministry of Health and Welfare and the Korea Centers for Disease Control and Prevention between 2003 and 2013. These reports were analysed by topics based on the AMR action plan of the World Health Organization (WHO), period of study, categories along the research pipeline and types of receiving institution. A total of 198 project reports were included, with total funding of US$18.3 million. Mean funding per award was US$92,750, with a median of US$71,714. Among the WHO-suggested criteria, the basic microbial research and surveillance sector accounts for 143 (72.2%) of all awards. Yearly project funding increased from US$961,476 in 2003 to US$1,553,294 in 2013. Operational research was 61.5% and product development was 0.7% of the basic microbial research and surveillance sector. By institution, academia received 145 awards (73.2%). During progress of the NARSCP, total research funding increased significantly, but most awards were focused on understanding the overall picture of the nationwide AMR status. More balanced funding is needed, and encouraging active participation of private and international sectors is also required in reducing AMR.

Active pulmonary tuberculosis and latent tuberculosis infection among homeless people in Seoul, South Korea: a cross-sectional study.

BACKGROUND: The aim of this study was to determine the prevalence rate of latent TB infection (LTBI) and active TB among homeless in Seoul metropolitan city, South Korea, and to compare the TB burden among homeless people with that of a control group. METHODS: The homeless participants were recruited from five sites between October 30, 2009 and April 12, 2010. LTBI was diagnosed through the QuantiFERON(R) TB Gold In-Tube(QFT-GIT) assay and a tuberculin skin test(TST) and, and active PTB was diagnosed based on chest radiography. RESULTS: Among 313 participants, the prevalence of LTBI was 75.9% (95% CI, 71.1-80.8%) and 79.8% (95% CI, 74.9-84.7%) based on a QFT-GIT assay and the TST, respectively, and that of active PTB was 5.8% (95% CI, 3.2-8.3%). The prevalence of LTBI among homeless participants was about five times higher than controls. Also, the age-specific prevalence rate ratio of active PTB was as high as 24.86. CONCLUSIONS: The prevalence rate of LTBI as well as active PTB among homeless people was much higher than that of the general population in South Korea. Thus, adequate strategies to reduce the TB burden among homeless people are needed.

Increased tuberculosis burden due to demographic transition in Korea from 2001 to 2010.

BACKGROUND: Notified tuberculosis (TB) cases in Korea have not decreased over the last decade (2001-2010). METHODS: To clarify the reasons, we analyzed an annual report on notified tuberculosis patients and age-specific population drift in Korea. RESULTS: Compared to the age-specific notified TB cases between 2001 and 2010, distinctive features in notified TB cases and new cases increased markedly in people aged 45-54 years and in patients over 65 years old, whereas those between 15-34 years in 2010 decreased drastically. In particular, notified TB individuals over 65 years old occupied 29.6% of the cases in 2010, which was 1.5 times higher than that in 2001. The main reason not to decrease in notified TB patients for the last decade (2001-2010) was due to the increasing elderly population as well as the aging of baby boomers, which have a higher risk of TB development. CONCLUSION: Korea needs to pay attention to the older population in order to successfully decrease the burden of TB in the future.

Complete Genome Sequence of Mycobacterium bovis BCG Korea, the Korean Vaccine Strain for Substantial Production.

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the only vaccine available against tuberculosis, and the strains used worldwide represent a family of daughter strains with distinct genotypic characteristics. Here, we report the complete genome sequence of M. bovis BCG Korea, the strain that will be actually used in Korea for vaccine production.

The national status of tuberculosis using nationwide medical records survey of patients with tuberculosis in Korea.

BACKGROUND: The epidemiology of tuberculosis (TB) has been assessed based on the data of the analysis of TB patients notified to the surveillance system in Korea. However, the national status of TB is not validated through this surveillance system. The objective is to determine the epidemiology of TB and to understand the accurate status of TB patients treated in private institutions. METHODS: Medical records of 53,579 patients who had been diagnosed with TB in 2008 were analyzed. RESULTS: Among 53,579 patients, the number of sputum smear positive cases was 15,639(29.2%) and the number of new cases was 39,191 (73.1%). The drug resistance rate of new cases was 5.3%, while the rate stood at 13.3% for TB patients with treatment history. The number of multi-drug resistant TB (MDR-TB) patients was 2,472 (4.6%), which consists of 2.9% of new cases and 9.3% of TB patients with prior treatment history. The number of extensively drug-resistant TB patients was 749 (1.4%), consisting of 1.1% of new cases and 2.2% of TB patients with prior treatment history. In terms of treatment outcomes, 66.4% of all TB patients, 70.5% of new cases, 64.4% of relapse cases, and 46.8% of MDR-TB cases were cured or completed. It was inferred that in 2008, the total number of TB patients reached 70,767, 145.6 per 100,000 people (95% confidence interval, 145.5~145.7). CONCLUSION: We conclude that the medical records review of the Health Insurance Review and Assessment Service (HIRA) data can be very effective in promoting the understanding of the current status of TB in private institutions.

Chest radiographic findings in primary pulmonary tuberculosis: observations from high school outbreaks.

OBJECTIVE: To describe the radiographic findings of primary pulmonary tuberculosis (TB) in previously healthy adolescent patients. MATERIALS AND METHODS: The Institutional Review Board approved this retrospective study, with a waiver of informed consent from the patients. TB outbreaks occurred in 15 senior high schools and chest radiographs from 58 students with identical strains of TB were analyzed by restriction fragment length polymorphism analysis by two independent observers. Lesions of nodule(s), consolidation, or cavitation in the upper lung zones were classified as typical TB. Mediastinal lymph node enlargement; lesions of nodule(s), consolidation, or cavitation in lower lung zones; or pleural effusion were classified as atypical TB. Inter-observer agreement for the presence of each radiographic finding was examined by kappa statistics. RESULTS: Of 58 patients, three (5%) had normal chest radiographs. Cavitary lesions were present in 25 (45%) of 55 students. Lesions with upper lung zone predominance were observed in 27 (49%) patients, whereas lower lung zone predominance was noted in 18 (33%) patients. The remaining 10 (18%) patients had lesions in both upper and lower lung zones. Pleural effusion was not observed in any patient, nor was the mediastinal lymph node enlargement. Hilar lymph node enlargement was seen in only one (2%) patient. Overall, 37 (67%) students had the typical form of TB, whereas 18 (33%) had TB lesions of the atypical form. CONCLUSION: The most common radiographic findings in primary pulmonary TB by recent infection in previously healthy adolescents are upper lung lesions, which were thought to be radiographic findings of reactivation pulmonary TB by remote infection.