• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.65-73
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• 2021

This study aimed to provide the basic data for the development of a simulation training program for new infectious diseases by analyzing the knowledge and educational needs of 119 paramedics regarding COVID-19 infection control. Data was obtained through a structured questionnaire survey of 186 paramedics from November 15th to 30th 2020. The study showed that 98 of the 119 paramedic subjects (52.7%) had not been educated regarding COVID-19. The knowledge level was 18.21±1.98 out of 25 points, with environmental control securing the lowest correct answers. The highest need for education was in the areas of prevention of transmission and spread, and employee safety control. The total average for educational needs was 3.81±.28 (4 point scale) with the highest educational need in the area of prevention of the spread and dispersion of the disease and employee safety management. There was a statistically significant difference in the knowledge of the general characteristics according to gender (t=-1.999, p=.047) and the educational demand was related to career (t=-1.999, p=.047) and, education levels (t=2.336, p=.021). Accordingly, it is necessary to plan a new infectious disease simulation education program that addresses the low-scoring areas and items with high educational needs which include the propagation path and spread prevention, environmental management, and employee safety management as per the findings of this study.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.68-74
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• 2009

Purpose : We assessed about the measles elimination in Korea according to analyzing national data on measles cases for 2002-2007. Methods : We estimated the effective reproduction number according to the proportion of imported cases and outbreak size. Results : Eleven cases, thirteen cases, six cases, six cases, 25 cases (60.0% were linked to 1 outbreak of 15 cases), and 180 cases (55.6% were linked 11 outbreaks of 2, 2, 2, 3, 3, 3, 5, 9, 9, 12, 50 cases) were reported in 2002, 2003, 2004, 2005, 2006 and 2007, respectively. In 2002-2007, R is 0.95 by imported case and 0.43 by outbreak sizes. In 2007, multiple chains of transmission occurred in hospital. Most of cases were below 4 ages and unvaccinated. We didn't find most of the infection source. Conclusion : We should prevent outbreak of susceptibility pocket like nosocomial infection, conduct reliable routine surveillance and epidemiological investigation to solve a problem of the measles elimination.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.12-24
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• 2013

Eradication of endemic malaria was declared in mid 1980's in Korea, but the number of malaria cases has been oscillating for the past 10 years since the reemergence of the disease in early 1990's. The occurrence of malaria has been concentrated near the demilitarized zone(DMZ), and the regional characteristics of the disease are evident. Considering the spatial variations of malaria incidence across the high-risk areas, the hotspot of the disease, it seems that the occurrence of the disease is influenced by the natural and human environment in the region. Malaria is an infectious disease that is transmitted to humans by the bites of vector-mosquitoes carrying malaria parasites, and it depends on specific climatic and sociodemographic factors. Malaria transmission is highly climate-sensitive, and temperature is the most important component. In addition, human contacts with vector-mosquitoes and the distance between human residence and mosquito habitats are crucial conditions determining malaria incidence rates. The present study aimed to test a hypothesis that the spatial characteristics of malaria incidence depended on local climatic conditions, relative proportions of mosquito habitats, and the distance between mosquito habitats and human residence using meteorological and satellite-based land cover data.

• Pediatric Infection and Vaccine
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• v.30 no.2
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• pp.73-83
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• 2023

Purpose: This study aimed to investigate the viral load dynamics in children with underlying malignancies diagnosed with symptomatic coronavirus disease 2019 (COVID-19). Methods: This was a retrospective longitudinal cohort study of patients <19 years old with underlying hemato-oncologic malignancies that were diagnosed with their first symptomatic severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (PCR)-confirmed COVID-19 infection during March 1 to August 30, 2022. Review of electronic medical records and telephone surveys were undertaken to assess the clinical presentations and transmission route of the patients. Thresholds of negligible likelihood of infectious virus was defined as E gene reverse transcription (RT)-PCR cycle threshold (Ct) value ≥25. Results: During the 6-month study period, a total of 43 children with 44 episodes of COVID-19 were included. Of the 44 episodes, the median age of the patients included was 8 years old (interquartile range [IQR], 4.9-10.5), and the most common underlying disease was acute lymphoid leukemia (n=30, 68.2%), followed by patients post-hematopoietic stem cell transplantation (n=8, 18.2%). Majority of the patients had mild COVID-19 (n=32, 72.7%), and three patients (7.0%) had severe/critical COVID-19. Furthermore, 2.3% (n=1) died of COVID-19 associated acute respiratory distress syndrome. The largest percentage of the patients showed E gene RT-PCR Ct value ≥25 between 15-21 days (n=13, 39.4%), followed by 22-28 days (n=10, 30.3%). In 15.2% (n=5), E gene RT-PCR Ct value remained <25 beyond 28 days after initial positive PCR. Refractory malignancy status (β, 67.0; 95% confidence interval, 7.0-17.0; P=0.030) was significantly associated with prolonged duration of E gene RT-PCR <25. A patient with prolonged duration of E gene RT-PCR Ct value <25 was suspected to have infectivity shown by the transmission of the virus to his mother at day 86 after his initial positive test. Conclusions: Children that acquire symptomatic COVID-19 during refractory malignancy state are at a high risk for prolonged shedding warranting PCR-based transmission precautions in this cohort of patients.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.273-282
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• 2009

The transmissible spongiform encephalopathies (TSEs) disease group are fatal neurodegenerative disorders affecting a wide range of hosts. The group includes kuru and Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep and goats and Bovine spongiform encephalopathy (BSE) in cattle. The exact nature of the infectious agent involved in the transmission of these diseases remains controversial. However, a central event in their pathogenesis is the accumulation in infected tissues of an abnormal form of a host-encoded protein, the prion protein (PrP). Whereas the normal cellular protein is fully sensitive to protease ($PrP^{sen}$), the disease-associated prion protein ($PrP^d$) is only partly degraded ($PrP^{res}$), its amino-terminal end being removed. BSE was first reported in the mid-80s in the UK. Ten years later, a new form of human prion disease, variant CJD (vCJD) developed in the wake of the BSE epidemic, and there is now strong scientific evidence that vCJD was initiated by the exposure of humans to BSE-infected tissues, thus indicating a zoonotic disease. However, the ban on the feeding of animal-derived proteins to ruminants, and the apparent lack of vertical transmission of BSE, have led to a decline in the incidence of the disease within cattle herd and therefore, an assumed decreased risk for human contacting vCJD. The origin of the original case(s) of BSE still remains an enigma even though three hypotheses have been raised. Hypotheses are i) sheep- or goat-derived scrapie-infected tissues included in meat and bone meal fed to cattle, ii) a previously undetected sporadic or genetic bovine TSE contaminating cattle feed or iii) originating from a human TSE through animal feed contaminated with human remains. A host cellular membrane protein ($PrP^C$), which is abundant in central nervous system tissue, appear to be conformationally altered in the diseased host into a prion protein ($PrP^{Sc}$). This $PrP^{Sc}$ is detergent insoluble and partially protease-resistant ($PrP^{res}$). The term $PrP^{res}$ is normally used to describe the protein detected after protease treatment, in techniques such as Western immunoblotting, and enzyme-linked immunosorbant assay using fresh/frozen tissue. Immunohistochemistry may performed with formalin-fixed tissues. Also, clinical signs of the BSE are one of the major diagnostic indicators. Recently, atypical forms (known as H- and L-type) of BSE have appeared in several European countries, Japan, Canada and the United States. An unusual case was also reported in a miniature zebu. The atypical BSE fall into two groups based on the relative molecular mass (Mm) of the unglycosylated $PrP^{res}$ band relative to that of classical BSE, one of the higher Mm (H-type) and the other lower (L-type). Both types have been detected worldwide as rare cases in older animals, at a low prevalence consistent with the possibility of sporadic forms of prion diseases in cattle. This raises the unwelcome possibility that vCJD could increase in the human population. Now, active surveillance program against BSE is going on in Korea. In regional veterinary service lab, ELISA is applied to screen the BSE in slaughter and confirmatory tests by Western immunoblotting and immunohistochemisty are carried out if there are positive or suspect in the screening test. Also, the ruminant feed ban is rigorously enforced. Removal of specified risk materials such as brain and spinal cord from cattle is mandatory process at slaughter to prevent the infected material from entering the human food chain.

• Pediatric Infection and Vaccine
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• v.27 no.1
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• pp.1-10
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• 2020

A cluster of severe pneumonia of unknown etiology in Wuhan City, Hubei province in China emerged in December 2019. A novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was isolated from lower respiratory tract sample as the causative agent. The current outbreak of infections with SARS-CoV-2 is termed coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO). COVID-19 rapidly spread into at least 114 countries and killed more than 4,000 people by March 11, 2020. WHO officially declared COVID-19 a pandemic on March 11, 2020. There have been 2 novel coronavirus outbreaks in the past 2 decades. The outbreak of severe acute respiratory syndrome (SARS) in 2002-2003 caused by SARS-CoV had a case fatality rate of around 10% (8,098 confirmed cases and 774 deaths), while Middle East respiratory syndrome (MERS) caused by MERS-CoV killed 858 people out of a total 2,499 confirmed cases between 2012 and 2019. The purpose of this review is to summarize known-to-date information about SARS-CoV-2, transmission of SARS-CoV-2, and clinical features of COVID-19.

• Quality Improvement in Health Care
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• v.8 no.1
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• pp.10-21
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• 2001

Background : The Clostridium difficile is the most important identifiable cause of nosocomial infectious diarrhea and colitis, which lengthens hospital stay. Recently incidence of C. difficile has been increasing in an university hospital, and an intervention for prevention and control of C. difficile associated diarrhea (CDAD) was in prompt need. Methods : Subjects were the patients in the neurosurgical intensive care unit(NCU) where C. difficile was most frequently isolated. To increase participation of various departments, we used the CQI method, because management of CDAD requires a wholistic approach including control of antibiotics, barrier precaution and environmental cleaning and disinfection. Duration of the CQI activities was 9 months from April to December 1999. Results : The identified problems were misuse and overuse of antibiotics, lack of consciousness of medical personnels and the possibility of transmission from the contaminated environment and tube feeding. Education for proper use of antibiotics and management of C. difficile infection, use of precaution stickers, supplement of handwashing equipments, emphasis on environmental disinfection, and the change of the process of tube feeding were done. The CDAD rate in NCU was significantly decreased after the CQI program (8.6 case per 1,000 patient days from January to April 1999 vs 4.8 from May to December 1999). The distribution of neurosurgical wards including NCU among the total number of isolated C. difficile from the clinical specimens dropped from 49.4% in January to April to 33,7% in May to December. The average hospital stay of the neurosurgical department changed from 19.6 days to 15.2 days. Also, the effect of the CQI activities for C. difficile may have affected the incidence of vancomycin resistant enterococci (VRE). Duration and dosage of certain antibiotics used in the NS department were decreased. The distribution of neurosurgical department in the number of VRE isolated patients declined from 18.4% to 11.1%. Conclusion : Infection control of resistant organisms such as C. difficile is likely to be successful when management of environmental contamination an collaborative efforts of decreasing the patients' risk factors such as antibiotics management and decreasing the length of hospital stay come simultaneously. For this work, related departments need to actively participate in the entire process under a common target through discussions for identifying problems and bringing up solutions. In this respect, making use of a CQI team is an efficient method of infection control for gathering participation and cooperation of related departments.

• The Korea Journal of Herbology
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• v.30 no.5
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• pp.67-74
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• 2015

Objectives : TheHaedokgumhwa-sanwater extract (HDKHS) is used in Korea, Japan and China as a traditional therapeutic agent to cure an infectious disease. But its study is not enough. Therefore, the present study focused on the elucidation of HDKHS to investigate the anti-inflammatory effects and to established the possible mechanisms involved in its action on LPS-stimulated immune response in murine macrophages.Methods : Inflammatory status was induced by LPS and measured by increasement of inflammatory mediators. LPS induced secretions of NO and PGE₂in RAW 264.7 cells were measured using griess reagent and enzyme-linked immunosorbent assay (ELISA) kit respectively. production of IL-6 was examined using ELISA kit and expression of IL-6 mRNA was measured by RT-PCR method. To investigate the effects of HDKHS on inflammatory mediators, such as iNOS, COX-2 and MAPKs, western blot and RT-PCR were performed.Results : HDKHS significantly reduced production of NO and PGE2 which were induced by LPS. Also, activation of IL-6 was reduced both protein and mRNA levels. The expressions of inflammatory mediator include iNOS and COX-2 were decreased by pretreatment with HDKHS. futhermore The result showed HDKHS down-regulate the LPS induced phosphorylation of ERK 1/2, one of the MAPK family, which is considered as a main regulator of transmission from pathogens to nucleus of immune cells.Conclusions : Our results suggest that the anti-inflammatory properties of HDKHS may stem from the inhibition of pro-inflammatory mediators via suppression of initiation of inflammatory response by inhibiting MAPKs signaling pathways.

• Biomedical Science Letters
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• v.10 no.2
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• pp.163-169
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• 2004

Worldwide, tuberculosis remains one of the leading infectious diseases, accounting for nearly 3 million deaths and more than 8 million new cases annually. DNA typing of Mycobacterium tuberculosis is important for the control of tuberculosis, since it can be used to track transmission route of tuberculosis, source of internal laboratory contaminations, and to answer questions on the nature of tuberculosis infections such as reactivation or exogenous reinfection of disease. At present, IS6110-based RFLP is the choice of method for typing large numbers of clinical isolates of M. tuberculosis, since it has the highest resolution power. However, RFLP requires long time, high cost and qualified experts, so only reference level laboratories can use the RFLP technique. In order to have an optional molecular typing method suitable for the clinical settings, this study evaluated the use of one of PCR-based typing methods, IS6110-based outward PCR for typing clinical isolates of M. tuberculosis. In brief, the results from this study showed that IS6110-based RFLP is useful to discriminate diverse clinical isolates of M. tuberculosis as well as to identify clinical isolates that belong to the same family or cluster groups that have been previously classified by RFLP analysis. In addition, the banding profiles resulted from IS6110-based outward PCR seemed to represent genomic characteristics of M. tuberculosis, since strains belong to the K-family generated unique band that is not present in any other strains but present only in the genome of K-family strains. The IS6110-based outward PCR was also shown to be useful with DNAs isolated directly from liquid cultures indicating this method can be suitable for typing M. tuberculosis in clinical settings.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.285-291
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• 2016

There has been an accelerating increase in water reuse due to growing world population, rapid urbanization, and increasing scarcity of water resources. However, it is well recognized that water reuse practice is associated with many human health and ecological risks due to numerous chemicals and pathogenic microorganisms. Especially, the potential transmission of infectious disease by hundreds of pathogenic viruses in wastewater is one of the most serious human health risks associated with water reuse. In this study, we determined the response of different bacteriophages representing various bacteriophage groups to chlorination in real wastewater in order to identify a more reliable bacteriophage indicator system for chlorination in wastewater. Different bacteriophages were spiked into secondary effluents from wastewater plants from three different geographic areas, and then subjected to various doses of free chlorine and contact time at $5^{\circ}C$ in a bench-scale batch disinfection system. The inactivation of ${\phi}X174$ was relatively rapid and reached ~4 log10 with a CT value of 5 mg/L*min. On the other hand, the inactivation of bacteriophage PRD1 and MS2 were much slower than the one for ${\phi}X174$ and only ~1 log10 inactivation was achieved by a CT value of 10 mg/L*min. Overall, the results of this study suggest that bacteriophage both MS2 and PRD1 could be a reliable indicator for human pathogenic viruses for chlorination in wastewater treatment processes and water reuse practice.