PHWR Public Health Weekly Report

Vol.15 No.8, February 24, 2022 Article TypeCOVID-19 Special ReportEpidemiology and SurveillanceNoncommunicable Disease Statistics

• COVID-19 Special Report 2022-02-24

  0 91 96

  Epidemiological characteristics of COVID-19 reinfection cases in the Republic of Korea

  Seong Jin Wang, Jin Soo Lim, Sang Eun Lee, Young Joon Park, Jungyeon Kim, Jin Gwack

  Public Health Weekly Report 2022; 15(8): 488-494

  

  

  Abstract

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  This case-control study monitored the epidemiological characteristics of reinfection cases since the beginning of the Coronavirus disease 2019 (COVID-19) outbreak in the Republic of Korea. By November 30, 2021, 142 COVID-19 suspected reinfection cases were reported. Findings indicated that the reinfection was an uncommon event (0.031%). The average age of reinfected patients was 37.1 years, and the mean time from primary to reinfection was 120 days. This study found that 66.7% of the reinfection cases were asymptomatic and that they occured more frequently in metropolitan areas (Seoul) (75.3%). Critical illness happened in 2.1% of the total reinfection cases.
  The reinfection outbreak during the Delta dominant period (Group 1) was six times greater than the Alpha and Beta dominant period (Group 2) (P<0.001), accounting for the high transmissibility of the Delta variant. No statistical differences in age group, sex, and symptoms were observed between the two groups (P=0.2698, P=0.5565, P=0.7574, respectively). Upon the Kaplan-Meier survival curve, the overall median survival time was 104 days (95% CI=96-114 days). The median survival time for each group was 120 days and 102 days, respectively.
  Among the 156,961 confirmed cases infected with SARS-CoV-2 from January 2020 to June 2021, the vaccination status of those reinfected during July-November 2021 was compared with that of residents who were not reinfected. The full and partial vaccinated groups were associated with 0.34 times the odds of reinfection compared with the unvaccinated group. These findings suggested that at least partial vaccination should be provided for all eligible persons, to reduce the risk of future infection.
  As of December 2021, there were growing concerns about COVID-19 reinfections due to the COVID-19 variant of concern Omicron outbreak. Thus, continuous monitoring and risk assessment studies are necessary to prevent ongoing COVID-19 reinfection cases.

• Epidemiology and Surveillance 2022-02-24

  0 131 92

  Status and characteristics of the SARS-CoV-2 variant outbreak in the Republic of Korea in January 2021

  Kim Il-Hwan, Park Ae Kyung, Lee Hyeokjin, Kim Heui Man, Kim Junyoung, Kim Jeong-Ah, No Jin Sun, Lee Chae young, Rhee JeeEun, Kim Eun-Jin

  Public Health Weekly Report 2022; 15(8): 497-510

  

  

  Abstract

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  As the coronavirus disease 2019 (COVID-19), which occurred in December 2019, spreads worldwide, variant viruses such as Alpha, Beta, Gamma, Delta, and Omicron are continuously emerging. The Delta variant from India spread rapidly among countries from April and became the dominant variant, and its incidence then decreased from December 2021. The Omicron variant, which was reported in South Africa in November, is now the dominant variant and is prevalent worldwide.
  The Korea Disease Control and Prevention Agency (KDCA) has been conducting genomic surveillance to track, analyze the source of infection and identify genetic mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As a result of conducting genome sequencing and PCR analysis on positive samples of confirmed cases related to local infection and overseas imports, a total of 118,450 variants of concern (VOC) (Delta 92,271, Omicron 22,703, Alpha 3,296, Beta 153, and Gamma 27) were confirmed from January 2020 to February 5, 2022. Regarding imported cases, after the Delta variant was first confirmed in Korea in April 2021, its detection rate was 39.3% in May and 76.2% in June. The Delta variant was confirmed in most cases; the detection rate of the Omicron variant in December was 52.8%, showing a changed trend, and that in January 2022 was 96.4%. Regarding domestic infection, Delta became the dominant variant with a detection rate of 59.6% in July 2021; however, Omicron bacame the dominant variant in January 2022 with a detection rate of 63.9%. As a result of the sub-lineage analysis of variants via whole genome analysis, the proportions of Omicron sub-lineages confirmed in domestic infections in January were 53.2%, 7.1%, and 1.4% for BA.1.1, BA.1, and BA.2, respectively.
  The KCDA has been providing evidence to prevent the spread of COVID-19 by rapidly detecting and analyzing variant viruses and conducting continuous monitoring to respond to the emergence of new SARS-CoV-2 variants.

• Epidemiology and Surveillance 2022-02-24

  0 89 51

  Pathogens causing viral encephalitis in the Republic of Korea

  Aram Lim, Hae Ji Kang, Ye-Ji Lee, Haeng rim Lee, Seung-Rye Cho, Myung-Guk Han

  Public Health Weekly Report 2022; 15(8): 511-517

  Abstract

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  Encephalitis, an inflammatory disease invading the brain parenchyma, presents a mortality rate of up to 20% and severe sequelae even after survival. The most common pathogen responsible for viral encephalitis is the herpes simplex virus, and the causative virus remains unknown in 70% of the cases. Since encephalitis can be caused by various pathogens, such as viruses and bacteria, the underlying cause often remains unidentified, with limited diagnostic tests focused only on specific pathogens. Therefore, an integrated encephalitis pathogen diagnosis system is necessary for examining various causative pathogens.
  As a preliminary investigation into the current status of pathogen infections causing viral encephalitis in the Republic of Korea, genetic detection tests for 14 major viruses were performed on 355 cases of cerebrospinal fluid from encephalitis and meningitis patients suspected of Japanese encephalitis or enterovirus infection.
  Consequently, the viral detection rate was 11.3% (40/355), and 10 different types of viruses were detected. The detection rates of the varicella zoster and herpes simplex viruses was the highest. Further, based on the age of the patients, those in their 30s exhibited the highest viral detection rate at 29.7% (11/37).
  This result can be utilized as the basic data for the selection of target pathogens to establish a surveillance system for encephalitis-causing pathogens as a preliminary investigation of the infection status of pathogens causing viral encephalitis in the Republic of Korea.

• Noncommunicable Disease Statistics 2022-02-24

  0 88 66

  Trends in prevalence of Depressive Disorder, 2014-2020

  Public Health Weekly Report 2022; 15(8): 518-519

  

  

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