• IMMUNE NETWORK
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• v.22 no.3
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• pp.23.1-23.12
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• 2022

Natural infection with severe acute respiratory syndrome-coronavirus-2 or vaccination induces virus-specific immunity protecting hosts from infection and severe disease. While the infection-preventing immunity gradually declines, the severity-reducing immunity is relatively well preserved. Here, based on the different longevity of these distinct immunities, we develop a mathematical model to estimate courses of endemic transition of coronavirus disease 2019 (COVID-19). Our analysis demonstrates that high viral transmission unexpectedly reduces the rates of progression to severe COVID-19 during the course of endemic transition despite increased numbers of infection cases. Our study also shows that high viral transmission amongst populations with high vaccination coverages paradoxically accelerates the endemic transition of COVID-19 with reduced numbers of severe cases. These results provide critical insights for driving public health policies in the era of 'living with COVID-19.'

• Applied Microscopy
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• v.22 no.1
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• pp.55-69
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• 1992

Viral disease incidence in the peanut fields at Iri, Kochang, Iksan and Puan in Chonbuk province was 0.93% on July and 8.46% on August in 1991. The causal pathogen was identified as peanut stripe virus (PStV) by the results of host plant reaction, immunological assay and observation of virus particles. Seed transmission rates of collected seeds from diseased plants ranged from 12.9 to 14.8% at peanut fields. PStV transmission was higher in small than in large seeds. Seed transmission of PStV was correlated with the age of the plant when inoculated; infection of young plants resulted in more seed transmission than did infection of old plants. Seed transmission of PStV was correlated with pod formation stages when inoculated at the 45th day after sowing; formed seeds for 2 weeks after inoculation resulted in more seed transmission than did formed seeds after 4 weeks. In seed transmission, this causal virus was moved to embryo and cotyledon through gynophore, pod, and funicle from leaves.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.981-991
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• 2023

Monkeypox (Mpox) virus, a member of the Poxviridae family, causes a severe illness similar to smallpox, which is characterized by symptoms such as high fever, rash, and pustules. Human-to-human transmission cases have been reported but remained low since the first recorded case of human infection occurred in the Congo in 1970. Recently, Mpox has re-emerged, leading to an alarming surge in infections worldwide since 2022, originating in the United Kingdom. Consequently, the World Health Organization (WHO) officially declared the '2022-23 Mpox outbreak'. Currently, no specific therapy or vaccine is available for Mpox. Therefore, patients infected with Mpox are treated using conventional therapies developed for smallpox. However, the vaccines developed for smallpox have demonstrated only partial efficacy against Mpox, allowing viral transmission among humans. In this review, we discuss the current epidemiology of the ongoing Mpox outbreak and provide an update on the progress made in diagnosis, treatment, and development of vaccines for Mpox.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.2
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• pp.213-227
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• 1995

Today, although hospital infectious diseases are readily diagnosed, are treatable and preventable, many of these continues to be a major health problem in the developing countries, as well as the advanced nations. In the advanced countries efforts for hospital infection control has been presented but in Korea. The importance of being knowledgeble concerning hospital infection control is not much recognized yet. Presently in Korea good quality of care and services in the hospital is a main issue of discussion, therefore the subject of hospital infection control can't be over emphasized. Hospital infection control measures ranged from almost non existent to none when the pathogen transmission were not fully understood. As the knowledge of the transmission and contraction of the diseases expanded, newer and more effective procedures evolved. To be vital it is required to have good system for hospital infection control and inspection, rules and regulations and many numbers of persons with dedication. The strategy has been applied for hospital infection control standards as outlined by the centers for disease control and prevention(CDC). The hospital infection control committee is the factor to be well managed. Especially nurses are the important part of any hospital infection control program because they are the one who makes function properly. It is also required the responsibility of every employer who has employees who are exposed to blood, blood products or other potentially hospital infectious materials. Laws enacted by agencies of the federal government but the emphasis, and the demands for initiating and maintaining these control measures should be practiced on a routine and daily basis. The forgoing facts and requirements will assist us in assuring our hospital infection control program is successful.

• Pediatric Infection and Vaccine
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• v.26 no.1
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• pp.66-70
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• 2019

Trans-placental neonatal human immunodeficiency virus (HIV) infection is common in Africa; however, it is not yet reported in the Republic of Korea. With the increasing incidence of HIV infection, especially in the reproductive age group, the risk of the vertical transmission of HIV is also increasing. We report the first case of HIV infection acquired in-utero in a newborn in Korea. The baby is growing well with normal development.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.425-429
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• 2018

Ureaplasma urealyticum (UU) infection can spread rapidly across populations and is associated with cervical intraepithelial neoplasms, human papillomavirus infections, and newborn mortality. This study aimed to provide information that could be used to protect public health and decrease the incidence and transmission of sexually transmitted infections (STIs), particularly among childbearing women. We examined the epidemiology of UU infection in Cheonan, South Korea. During 2006-2017, 4,050 specimens were submitted for STI screening using a multiplex polymerase chain reaction (PCR) assay. Data were analyzed for UU infection cases using the R statistical program and categorical data were analyzed using the chi-square test, and p-values <0.05 were considered statistically significant. Positive PCR results were shown in 17.8% of the total specimens, in 9.0% of men, and in 18.7% of women. Individuals in their teenaged years and individuals aged 20-29 years accounted for the largest proportions of UU-positive specimens. Although Mycoplasma hominis was the most prevalent bacterium in 2006, it was superseded by UU in 2017. Of the 870 UU-positive specimens, 50.1%, 33.1%, 13.4%, and 2.8% had single, double, triple, and quadruple infection, respectively. UU was most common among Korean individuals aged 20-29 years, indicating a high risk of maternal-to-infant transmission that should be addressed through rapid diagnosis, treatment, and management.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.4
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• pp.311-318
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• 2020

Chronic hepatitis B viral (HBV) infection remains a major health threat, especially in high-prevalence areas. Most infants infected by mother-to-infant HBV transmission become chronic carriers. In Taiwan, many important preventive interventions have been implemented to block the perinatal transmission of HBV in the past 35 years. The first nationwide universal HBV vaccination program was launched in Taiwan in July 1984. The three-dose HBV vaccine completion rate reached 98.1% in 2018. The prevalence of Hepatitis B surface antigen (HBsAg) decreased from 9.8% in pre-vaccinated period in 1984 to 0.5% in the vaccinated cohort in 2014. The incidence of hepatocellular carcinoma in children aged 6-9 years significantly declined from 0.52 to 0.13 per 100,000 children born before and after 1984, respectively. Furthermore, we have performed a maternal HBV screening program during pregnancy since 1984, with the screening rate peaked at 93% in 2012. The HBsAg- and HBeAg-seropositive rate in pregnant women declined from 13.4% and 6.4% in 1984-1985 to 5.9% and 1.0% in 2016, respectively. To closely control perinatal HBV infection, we have administered hepatitis B immunoglobulin immediately after birth and checked the serum level of HBsAg and anti-HBs in high-risk babies born to HBsAg-seropositive mothers, irrespective of their HBeAg status, since July 2019. We have also adopted short-term antiviral treatments such as tenofovir 300 mg daily in the third trimester for highly viremic mothers and reduced the perinatal infection rates from 10.7 to 1.5%. Through all these efforts, we expect to meet the global goal of eliminating HBV infection by 2030.

• Parasites, Hosts and Diseases
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• v.37 no.3
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• pp.149-156
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• 1999

Pneumocystis carinii is pulmonary pathogen of immunocompromised humans or other mammals. Its infection results from activation of organism involves in latent infection or form new infection through the air. Almost all children are known to be infected within 2 to 4 years of birth, though prenatal transplacental transmission has not yet been demonstrated. In this study we observed experimental P.carinii infection in neonatal rats, thus investigating the possibility of transplacental vertical transmission by Diff-Quik staining of the lung impression smears and in-sity hybridization for lung sections. The postive rate of P.carinii infection in immunosuppressed maternal rats was 100%, but that in normal maternal rats was 0%. Cystic forms of P.carinii were observed in three of six 1-week old neonatal rats born of heavily infected mothers, but none of them was positive by in-situ hybridization. Five weeks after birth, cystic forms were detected in four neonatal rats. In the lobes of the lungs, no predilection site of P.carinii was recognized. Counts of cystic forms on smears and the reactivity of in-situ hbridization in the lungs of neonatal rats 0 were signficantly lower than in maternal rats. The present findings suggest that P.carinii is rarely transmitted through the placenta and proliferates less successfully in the lungs of neonatal rats than in mothers.

• Journal of Yeungnam Medical Science
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• v.39 no.3
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• pp.223-229
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• 2022

Background: The first large coronavirus disease 2019 (COVID-19) outbreak outside China occurred in Daegu. In response, we developed infection prevention measures for surgical patients during the outbreak at our hospital and retrospectively reviewed the outcomes of COVID-19-related surgical patients. Methods: We reviewed the medical records of 118 COVID-19-related surgical patients and monitored their clinical outcomes until March 31, 2021. We also interviewed healthcare workers who participated in their perioperative care at Kyungpook National University Chilgok Hospital. The perioperative management guidelines for COVID-19-related patients were prepared through multidisciplinary discussions, including the infection control department, surgical departments, and anesthesiology department before and during the COVID-19 outbreak. Results: One standard operating room was temporarily converted to a negative-pressure room by increasing the exhaust air volume, creating a relative pressure of -11.3 Pa. The healthcare workers were equipped with personal protective equipment according to the patient's classification of the risk of COVID-19 transmission. The 118 COVID-19-related patients underwent emergent surgery in the negative-pressure room, including three COVID-19-confirmed patients and five COVID-19-exposed patients. Conclusion: All surgeries of the COVID-19-related patients were performed without specific adverse events or perioperative COVID-19 transmission. Our experience setting up a negative-pressure operating room and conservative perioperative protocol to prevent COVID-19 transmission will help plan and execute infection control measures in the future.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.699-702
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• 1998

This study investigates the population model of the spread of HIV/AIDS which the infection is generated by an infectious in dividual in a population of susceptibles. 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.