• Communications of the Korean Mathematical Society
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• v.17 no.1
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• pp.175-187
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• 2002

The existence and uniqueness of steady states for the age structured S-I-R epidemic model is considered. Intercohort form with external force is considered for the force of infection. Existence is obtained for nonvanishing external force of infection. Uniqueness is shown for the case where there is no vertical transmission of the disease.

• BMB Reports
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• v.33 no.1
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• pp.63-68
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• 2000

Most baculoviruses have an ecdysteroid UDP-glucosyltransferase (egt) gene, whose product inactivates ecdysteroid within the infected host. Bomhyx mori larvae infected with BmEGTZ, a mutant B. mori nucleopolyhedrovirus (BmNPV) in which the egt gene has been inactivated, die more rapidly compared to larvae infected with wild-type BmNPV. In this study, the profile of hemolymph proteins, and progression of virus infection in BmEGTZ- and BmNPV-infected B. mori larvae, was analyzed by SDS-PAGE and histochemically. These analyses showed that virus-encoded and virus-induced proteins were expressed quicker in BmEGTZ-infected larvae than in BmNPV-infected larvae. This suggests that the decrease in time to death, following BmEGTZ infection, results from the stimulation of virus-specific protein expression. In order to examine the effect of ecdysteroid on virus transmission, the profile of hemolymph proteins, and progression of virus infection, were analyzed following an ecdysteroid injection of BmEGTZ- or BmNPV-infected larvae. In the BmNPV-infected larvae, ecdysteroid treatment had no apparent effect on hemolymph protein expression. This suggests that the injected ecdysteroid was inactivated by the BmNPV-expressed ecdysteroid UDP-glucosyltransferase. An Ecdysteroid injection into BmEGTZ-infected larvae increased the speed of virus-specific protein expression and virus transmission. These results suggest that ecdysteroid stimulates protein expression, which in tum results in the stimulation of virus transmission.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.64-74
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• 2024

Purpose: Despite the recent increased number of nosocomial measles, the outbreak investigation reports are not usually standardized, thus posing unclear understanding of magnitude of its public health burden. We used the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement, to compare nosocomial outbreaks and synthesize evidence to prevent hospital transmission of measles. Methods: A PubMed, Web of Science, Embase, Scopus, and Cochrane search in English, using the medical subject headings "measles," "nosocomial," "hospital," and "healthcare," was performed. We evaluated the quality of outbreak reports of nosocomial measles infection worldwide using the ORION statement findings and recommendations. Results: We reviewed 24 studies in accordance to the ORION statement. Measles transmission in healthcare settings is a significant burden on the morbidity, mortality, and economy of measles. The healthcare workers' booster vaccination guidelines should be monitored and enhanced during the post-elimination period of measles. The outcomes of infections must be explicit for outbreak reports. Conclusions: This study identified the epidemiological and clinical characteristics of nosocomial measles infections and provided strong evidence for infection control policies in hospitals.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4747-4753
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• 2016

Background: The prevalence of Helicobacter pylori (H. pylori) infection in Indonesia has been reported to be exceedingly low. The purpose of our study was to confirm whether this is the case in Northern Jakarta using a sensitive 13C-urea breath test (UBT), and to examine any associations with lifestyle/environment factors and potential routes of transmission. Methods: We recruited a total of 196 subjects from a low-income community in Northern Jakarta, Indonesia, data from 193 who completed a questionnaire about their lifestyle/environment and had UBT being included as the final. Odds ratios (ORs) adjusted for sex and age with 95% confidence intervals (CIs) were calculated using a logistic regression model. Results: The overall H. pylori infection rate was 15.0% (95%CI, 10.3-20.9), with variation among Javanese (9.1%, total=77), Buginese (40.0%, 35), Betawi (9.1%, 33), Sundanese (3.7%, 27), and Batak (40.0%, 5). On multivariate analysis, the ORs for intake of soybean milk, cucumber more than once a week, infrequent hand washing practice before meals, and alcohol consumption were 0.10 (95%CI: 0.01-0.97), 6.61 (95%CI: 1.87-23.3), 4.10 (95%CI: 1.15-14.6), and 61.9 (95%CI: 1.67-2300.8), respectively. Rates for Buginese (OR=7.84; 95%CI: 1.82-33.8) and Batak (OR=20.1; 95%CI: 1.90-213.2) were significantly higher than for Javanese. Conclusions: The H. pylori infection rate in this study was relatively low, in line with previous studies. Regarding ethnicity factors, Buginese and Batak reported eating food using fingers more frequently than Javanese, Betawi, and Sundanese. Our study indicated that person-person transmission is possible in this low prevalence area. The low infection rates for H. pylori among Javanese, Betawi, and Sundanese ethnics could be partly due to their sanitary practices.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.2
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• pp.183-193
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• 2013

The characteristics of dental treatment makes the dental staff frequently contact with patient directly. Also the daily use of high-handpieces, sharp instruments, and needles often causes bleeding on oral cavity. Therefore, the risk of cross transmission grows up. The pathogen from dental practice could spread on not only the practice itself but also the dental laboratory with contaminated impressions and prosthesis. Dental clinic staffs (dentists, dental hygienists and dental technicians) should recognize all the patients have a possibility of cross contamination, and try to prevent the transmission of infection by proper infection control. In this study, we review the articles about disinfection methods and chemical infection agents used for dental impressions, and try to figure out the suitable and effective infection control system of dental impressions.

• The Korean Nurse
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• v.27 no.2 s.145
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• pp.20-25
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• 1988

• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.1-9
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• 2016

The Zika virus, a flavivirus related to dengue and Japanese encephalitis was discovered in the Zika forest in Uganda, 1947. Since Zika virus was first reported in Brazil in May 2015, infections have occurred in at least 40 countries, especially in the Americas. Zika virus infection usually is asymptomatic or causes mild illness, but may be related to severe clinical manifestations, particularly microcephaly and Guillain-$Barr{\acute{e}}$ syndrome. Although the possibility of autochthonous Zika virus transmission in South Korea is low, the imported cases and Zika virus-transmitting mosquito should be adequately monitored and promptly managed. In addition, enhancing preparedness for Zika virus infection are needed.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.317-325
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• 2022

Hypoxia-inducible factor-1 alpha (HIF-1α) is one of the master regulators of immune and metabolic cellular functions. HIF-1α, a transcriptional factor whose activity is closely related to oxygen levels, is a target for understanding infectious disease control. Several studies have demonstrated that HIF-1α plays an important role during the infectious process, while its role in relation to parasite virulence has not been addressed. In this work, we studied the expression levels of HIF-1α and related angiogenic vascular endothelial growth factor A (VEGF-A) in human macrophages infected with promastigotes of hypo- or hyper-virulent Leishmania major human isolates. L. major parasites readily subverted host macrophage functions for their survival and induced local oxygen consumption at the site of infection. In contrast to hypo-virulent parasites that induce high HIF-1α expression levels, hyper-virulent L. major reduced HIF-1α expression in macrophages under normoxic or hypoxic conditions, and consequently impeded the expression of VEGF-A mRNA. HIF-1α may play a key role during control of disease chronicity, severity, or outcome.

• Korean Journal of Veterinary Research
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• v.60 no.1
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• pp.15-18
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• 2020

Canine heartworm disease is a vector-borne disease that is transmitted from dog to dog by mosquitoes. It causes epidemics that disrupt the health environments of dogs and are burdensome for many dog owners. Recent trends of changing temperatures and weather conditions in South Korea may have an impact on the population of mosquitoes, and it affects the population of dogs at risk of heartworm infection. Mathematical modeling has become an important measure for analyzing the epidemiological characteristics of infectious diseases. However, canine heartworm infection transmission has not been reported yet through mathematical modeling. We develop a mathematical model of canine heartworm infection to predict the population of infected dogs depending on the vector (mosquito) population using a susceptible, exposed, infected, and recovered model. Simulation results show that after 1 year, 3,289 dogs out of 73,602 (about 4.5%) are exposed and 134 (about 0.2%) are infected. Only 0.2% of susceptible dogs become infected after 1 year. However, if all exposed dogs are maintained in the same circumstances without any treatment, then the number of infected subjects will increase over time. This may increase the possibility of other dogs, especially dogs that live outside, being infected.

• Quality Improvement in Health Care
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• v.19 no.1
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• pp.30-42
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• 2013

Objectives: This study was intended to check if the "Creating Clean Wards" project, which is an innovative reinforced campaign activity targeting infection control strategies and active surveillance cultures for VRE (vancomycin resistant enterococci) high-risk patients to be admitted in the NS (neuro-surgery) wards, would be reduced the incidence rates of VRE acquisition, transmission rates. Methods: 75 subjects of the VRE high-risk patients were surveyed by carrying out active surveillance cultures of VRE colonization 11 times from January to March, 2012. And the retrospective study was conducted dividing them into two groups. Results: The incidence rates of VRE acquisition was reduced to 3.67 cases per 1,000 patients day in the control group and to 2.88 cases in experimental group, which was not statistically significant (p = .753). VRE transmission rates of 0.0015 per day before the project tended to increase to 0.0019, although not statistically significant (p = .650). As a result of multivariate analysis with regard to using glycopeptide antibiotics in order to find out risk factors of VRE colonization, the patients who had been treated with glycopeptide until VRE colonization showed 274.41 times higher rate. Conclusion : For effective VRE infection control in NS wards, We should carry out active surveillance culture regularly, especially patient of using glycopeptide. And block the spread of VRE by strengthening infection control through the strict isolation and the changed mind-set of members motivated by the "Creating Clean Wards" campaign.