• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.2
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• pp.89-95
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• 1999

This study investigates the population model of the spread of HIV/AIDS which the infection is generated by an infectious individual in a population of susceptible. A mathematical model is presented for the transmission dynamics of HIV infection within the communities of homosexual males. The pattern on the epidemic character of HIV, the causative agent of AIDS, was analysed by the mathematical model of AIDS system which is derived according to the ecological relationship between five epidemilogic states of individuals. The computer simulation was performed using real data and the following conclusions are drawn on the basis of the simulations. 1. The model structure and the algorithm described n the thesis is good. 2. In proportion to increase Ro, the population of AIDS patient increases and the time of its widespread reaches earlier. 3. The AIDS patients will be maximum between 7 and 21 years after an attack of AIDS and widespread between 10 and 20 years. 4. Considering the properties of the incubation periods, the maximum number of infected person is increased, and the attack rate is decreased.

• Tuberculosis and Respiratory Diseases
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• v.80 no.1
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• pp.21-26
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• 2017

It is well established that health care workers (HCWs) have a considerably higher risk of occupationally acquired tuberculosis (TB). To reduce the transmission of TB to HCWs and patients, TB infection control programs should be implemented in health care settings. The first and most important level of all protection and control programs is administrative control. Its goals are to prevent HCWs, other staff, and patients from being exposed to TB, and to reduce the transmission of infection by ensuring rapid diagnosis and treatment of affected individuals. Administrative control measures recommended by the United States Centers for Disease Control and Prevention and the World Health Organization include prompt identification of people with TB symptoms, isolation of infectious patients, control of the spread of the pathogen, and minimization of time spent in health care facilities. Another key component of measures undertaken is the baseline and serial screening for latent TB infection in HCWs who are at risk of exposure to TB. Although the interferon-gamma release assay has some advantages over the tuberculin skin test, the former has serious limitations, mostly due to its high conversion rate.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.211-217
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• 2021

The purpose of this study is based on the convergence establishment of a coronavirus infection management system that can occur during clinical trials by grasping the knowledge of corona, infection possibility, infection prevention possibility, and implementation level of infection prevention behavior of radiologists working at K University Hospital. It is in providing data. This study was a descriptive research study, and data were collected from 50 radiologists working at K University Hospital from March 25 to June 30, 2020. The characteristics of the subjects and their knowledge of the COVID-19, the possibility of infection, the possibility of infection prevention, and the level of implementation of infection prevention actions were surveyed, and the collected data were analyzed with SPSS 25.0. The frequency and percentage were calculated for the general characteristics and infection-related characteristics of the subjects. The correlation between variables was analyzed by Pearson's correlation coefficient, and the factors influencing the progression of infection prevention behavior were analyzed by multiple regression analysis. Factors influencing COVID-19 infection prevention behavior shown in this study were 1.7 points for infection prevention behavior when corona knowledge increased by 1 point, and infection prevention activity increased by 11.3 points when the level of transmission pathway recognition rose 1 point. When the figure rose by 1 point, the infection prevention behavior increased by 4.2 points. When looking at the standard regression coefficient, preventive behavior is performed. Among knowledge, transmission path perception, and anxiety, the factor that has the greatest influence was the perception of the transmission path of COVID-19. As factors influencing the implementation of infection prevention actions, knowledge of COVID-19, awareness of transmission paths, and anxiety appear to be the potential of infection prevention, so in the event of a corona outbreak, information on infectious diseases and education on the possibility of infection prevention should be provided to promote the implementation of preventive action.

• The Korean Journal of Emergency Medical Services
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• v.20 no.3
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• pp.49-56
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• 2016

Purpose: The purpose of this study was to investigate the effect of a pathogenic bacteria filtration instrument for infection prevention during mouth-to-mouth ventilation. Methods: Two kinds of face shields were used for the study. One rescuer blew the filter through a bag valve mask and the filter was then cultured for bacteria. The mask was tested both on the front and back side. Results: Two kinds of face shields including the KF shield and CM shield were tested. The KF shield has received national certification and it prevented transmission of bacterial infection but the CM shield showed the opposite result and did not prevent bacterial transmission. Pathogenic bacteria were found on the back of the CM shield. Conclusion: A certified face shield is very important to prevent bacterial transmission. Face shields should be demonstrated and used by paramedic students.

• The Plant Pathology Journal
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• v.23 no.2
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• pp.103-105
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• 2007

Mechanical transmission of barley seedlings with barley yellow mosaic virus (BaYMV) is generally inefficient and is the major constraint for testing cultivar resistance to the virus. To explore mechanical transmission, BaYMV-infected barley plants were grown at different conditions and used as inoculum sources to seedlings of susceptible barley cultivar Baegdong. Extracts prepared from BaYMV-infected Baegdong plants at 47, 53, 74, and 90 days after symptom appearance (DASA) and grown at 10 and $12^{\circ}C$ gave 10, 30, 68 and 76% infection, respectively on inoculated susceptible barley cv. Baegdong seedlings. While Jinyangbori, another susceptible cultivar obtained 95% infection rate inoculated with extracts from 90 DASA disease source and grown at $10/12^{\circ}C$. However, low infection rates were obtained when the virus sources were grown in a greenhouse at $15-18^{\circ}C$. Our results indicate that longer incubation period and lower temperature are required for virus accumulation and stability.

• IMMUNE NETWORK
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• v.14 no.4
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• pp.187-200
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• 2014

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are the most common cause of genital ulceration in humans worldwide. Typically, HSV-1 and 2 infections via mucosal route result in a lifelong latent infection after peripheral replication in mucosal tissues, thereby providing potential transmission to neighbor hosts in response to reactivation. To break the transmission cycle, immunoprophylactics and therapeutic strategies must be focused on prevention of infection or reduction of infectivity at mucosal sites. Currently, our understanding of the immune responses against mucosal infection of HSV remains intricate and involves a balance between innate signaling pathways and the adaptive immune responses. Numerous studies have demonstrated that HSV mucosal infection induces type I interferons (IFN) via recognition of Toll-like receptors (TLRs) and activates multiple immune cell populations, including NK cells, conventional dendritic cells (DCs), and plasmacytoid DCs. This innate immune response is required not only for the early control of viral replication at mucosal sites, but also for establishing adaptive immune responses against HSV antigens. Although the contribution of humoral immune response is controversial, $CD4^+$ Th1 T cells producing IFN-${\gamma}$ are believed to play an important role in eradicating virus from the hosts. In addition, the recent experimental successes of immunoprophylactic and therapeutic compounds that enhance resistance and/or reduce viral burden at mucosal sites have accumulated. This review focuses on attempts to modulate innate and adaptive immunity against HSV mucosal infection for the development of prophylactic and therapeutic strategies. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses. Thus, we summarized the current evidence of various immune mediators in response to mucosal HSV infection, focusing on the importance of innate immune responses.

• Mycobiology
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• v.30 no.1
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• pp.47-50
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• 2002

Seed-borne fungi of some maize cultivars/lines grown during the months from May to September of 2001, collected from Dongguk University farm, Go Young City, IL Sang Gu, Korea were detected by blotter method. In all six fungi namely Alternaria alternata(Fr.) Keissler, Aspergillus niger Van Tiegh, Fusarium moniliforme Sheldon, Fusarium sp., Penicillium sp. and Ustilago zeae Unger. were found to associated with maize seeds. Prevalence of seed-borne fungi also varied. The highest percentages of seed-borne fungi were recorded with Fusarium moniliforme and the lowest in Penicillium sp. Transmission of all seed-borne pathogens from seeds to seedlings were also detected by test tube seedling symptom test. Among the seed-borne fungi, Alternaria alternata, Fusarium moniliforme and Fusarium sp. produced distinct seed rot and seedling infection symptoms. All the transmitted seed-borne fungi might be caused primary source of infection to the maize crop.

• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.228-235
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• 1999

Objectives: Despite the importance of human immunodeficiency virus(HIV) transmission through heterosexual contact, the features of heterosexual transmission has not been well studied in Korea. So we conducted a cross sectional study to determine the transmission rates in married couples and assess risk factors for male to female heterosexual transmission of HIV. Methods: 169 HIV-infected males and their female sex partners were recruited from 1985 to tune 1998. We examined female sex partner's HIV infection status and interviewed male index partners and their female sex partners about demographic characteristics and sexual practices. We analysed heterosexual transmission rate by epidemiologic characteristics, disease status and sexual practices. And we assessed risk factors for HIV infection by univariate and multivariate analysis. Results: 30 female sex partners were infected at enrollment, yielding an transmission rate of 17.8%. Among couples who had used condoms consistently, none of the female sex partners was infected with HIV. In univariate analysis the significant risk factors were full blown AIDS status (OR=4.1, 95% CI: 1.49-11.43) and low CD4 T cell count of index partners at enrollment (OR=7.8, 95% CI: 2.19-27.80). In multivariate analysis HIV-1 RNA levels was significant risk factor when adjusted by CD4 T cell courts and mean sexual contacts per month (OR=19.2, 95% CI: 1.03-357.59) Conclusion: The risk of male to female heterosexual transmission increased with advanced stages of HIV infection in the index male partners.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.146-153
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• 1997

The microsporidian infection with Nosema bombycis, reconfirmed its high virulence and transovarial tranmissibility, however, the characteristic symptom of the spots like pepper grains on the diseased larval skin was no more recognized by present varieties of the silkworm. Transovarial transmission rate detected from moth was above 90% in dead eggs or dead larvae in the rearing by mulberry leaves, 80% in the newly hatched larvae starved to death. Transovarially transmitted N. bombycis was easily observed from dead eggs and larvae, and were suggested an individual inspection of a few of dead eggs for detection of the pathogenic spores. The progeny population provided indicative factors on the sampling of predictive and corrective inspection. The higher concentration of N. bombycis spores included in the hindabdormal part of infected moth, applicative on the simple method of indivisual moth inspection. For the predictive inspection of growned 5th-instar larvae, N. bombycis infection was detectable without microscopic observation by the unique symptom of turbid milky-white spots on the silk gland. Inspection of the meconia artificially discharged from silkworm moth, was also succesful of microscopic observation before crossing, without killing or homogenize the moths. The results provided a basis of rational methods for the inspection of N. bombycis infection of the silkworm.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1184-1193
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• 2015

Monitoring for megalocytivirus infection was conducted for ten months from March to December in 2013 in 15 aquatic farms culturing, red sea bream, rock bream, rock fish and black sea bream around Tongyoung coastal area in Korea, to assess spatial and temporal variability of detection prevalence, and to explore possible links with seawater temperature. In nested-PCR targeted major capsid protein (MCP) gene, asymptomatic megalocytivirus infection was detected in the externally healthy farmed fish with a significant prevalence in range from 0 to 58.3% for ten months. Higher prevalence of megalocytivirus (46.7% - 57.1%) was observed in high water temperature season from September to November than that in other months with lower prevalence of 0.0% to 20.0%. Even though an acute infection of megalocytivirus was occurred in rock bream (positive in the first PCR) with high mortality in one of fifteen farms, there was no expansion or transmission of the disease to the rock fish and red sea bream culturing in net cage just proximal to the rock bream cage in which disease outbreaked. Nucleotide sequence analysis of the cloned MCP gene isolated asymptomatically infected rock fish revealed that the megalocytivirus in this study was clustered together with the rock bream iridovirus (RBIV) under the subgroup II of the genus megalocytivirus (Iridoviridae), which is known to be the major megalocytivirus strain in Korea. The typical histopathological signs were not found in the spleen of rock fish asymptomatically infected by megalocytivirus. Experimental infection of rock bream with the spleen homogenate of the rock fish infected asymptomatically did not induce any mortality unlike the homogenate of infected rock bream with hih mortlity. However, these results may suggest that the asymptomatic infection of megalocytivirus in other fish species can be a potential risk threatening aquaculture industries as a transmission factor of megalocytivirus to susceptible fish species, especially rock bream.