• Journal of Korean Clinical Nursing Research
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• v.15 no.1
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• pp.55-65
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• 2009

Purpose: The purpose of this study was to compare the 1% chlorhexidine gluconate/61% ethanol (CHG/ethanol), 45% ethanol/18% 1-propanol (ethanol/propanol) and 7.5% povidone-iodine (PVI) scrub with brush to evaluate their antimicrobial effect. Method: Utilizing repeated measures design, 9 nurses participated in the study. Glove juice sampling procedure was used to evaluate microbial hand counts before the surgical hand antisepsis, one minute after hand wash, and after the surgery. Results: Waterless rub using CHG and ethanol combination resulted in a 3.94 log reduction at 1 min and 2.78 log reduction at 3 hrs. Ethanol/propanol resulted in a 2.42 at 1 min and 2.22 at 3 hrs. The traditional scrub using PVI with brush resulted in a 0.94 at 1 min and 0.95 at 3 hrs (p=.003) and 3 hrs (p=.026) after the surgical hand antisepsis. Repeated measures ANOVA results showed that there was a statistically significant difference among group (p=.002). Duncan post hoc test result showed that the PVI was less effective (p<.05) in sterilizing microbials on hands than CHG/ethanol or ethanol/propanol. Conclusion: Both of the two alcohol-based antiseptic rubs are acceptable alternatives to the PVI with brush for surgical hand antisepsis.

• Parasites, Hosts and Diseases
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• v.48 no.3
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• pp.237-243
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• 2010

Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. pal pale (15.7%), Neotrombicula tam/yai (14.3%), L. orientate (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticutum (0.8%), while the remaining 3 species, L subintennedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpate (21.4), were observed during the spring season.

• IMMUNE NETWORK
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• v.21 no.2
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• pp.14.1-14.17
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• 2021

Scrub typhus develops after the individual is bitten by a trombiculid mite infected with Orientia tsutsugamushi. Since it has been reported that pneumonia is frequently observed in patients with scrub typhus, we investigated whether intranasal (i.n.) vaccination with the outer membrane protein of O. tsutsugamushi (OMPOT) would induce a protective immunity against O. tsutsugamushi infection. It was particular interest that when mice were infected with O. tsutsugamushi, the bacteria disseminated into the lungs, causing pneumonia. The i.n. vaccination with OMPOT induced IgG responses in serum and bronchoalveolar lavage (BAL) fluid. The anti-O. tsutsugamushi IgA Abs in BAL fluid after the vaccination showed a high correlation of the protection against O. tsutsugamushi. The vaccination induced strong Ag-specific Th1 and Th17 responses in the both spleen and lungs. In conclusion, the current study demonstrated that i.n. vaccination with OMPOT elicited protective immunity against scrub typhus in mouse with O. tsutsugamushi infection causing subsequent pneumonia.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.188-191
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• 2003

Tsutsugamushi fever is a serious febrile disease outwardly similar to malaria and various arboviral infections. The endemic area is Asia-Pacific. This disease are generally associated with disturbed habitats favoring large populations of vector larval trombiculid mites. Therapy with tetracycline, chloramphenicol or ciprofloxacin is currently recommanded. Unfortunately these drugs is suboptimal for children and pregnant women. Recently, azithromycin has been proven to be effective in therapy of scrub typhus. There is no evidence that azithromycin causes adverse reaction to developing fetus or children. We report four cases of tsutsugamushi fever in children successfully treated with azithromycin. This is the first report describing clinical application of azithromycin to tsutsugamushi fever in Korean children.

• Biomedical Science Letters
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• v.17 no.4
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• pp.367-370
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• 2011

Studies on the relative abundance of potential vectors of scrub typhus was conducted from April to October 2009 at the Jangseong of Jeonnam Province, Korea. Among the total 62 field rodents collected by the Sherman collapsible traps, 56 rodents were $Apodemus$ $agrarius$ (90.3%), 4 were $Crocidura$ $lasiura$ (6.4%) and 2 were $Cricetulus$ $triton$ $nester$ (3.2%). Out of the 62 field rodents, 39 were parasitized by chiggers, showing 62.9% of the infestation rate and 80.0 of the chigger index. Chigger index of $A.$ $agrarius$ and $C.$ $triton$ $nester$ were 79.9, 82.0, respectively. But chigger mite was not collected from $C.$ $lasiura$. From the trapped field rodents, 3,120 chiggers were collected and identified with 6 species of 2 genera. $Leptotrombidium$ $scutellare$, the vector species of tsutsugamushi disease, was the dominant species, showing 2,276 chiggers (72.9%). $L.$ $pallidum$ was the second dominant species showing 346 chiggers (11.0%). The distribution of chigger mites was showed the different dominant species according to seasons. $L.$ $pallidum$ was the predominant chigger collected in April (34.8%), May (77.8%) and Jun (39.3%), whereas $L.$ $scutellare$ was the predominant chigger collected in September (78.78%) and October (76.8%).

• Journal of Microbiology
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• v.39 no.3
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• pp.186-194
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• 2001

Scrub typhus, caused by Orientia tsutsugamushi infection, is clinically and histopathologically characterized by local as well as systemic inflammatory reactions, indicating that orientiae induce mechanisms that amplify the inflammatory response. To reveal underlying mechanisms of chemoattraction and activation of responding leukocytes, expression of chemokine and tumor necrosis factor alpha (TNF-$\alpha$) genes in murine peritoneal macrophages after infection with the obligate intracellular bacterium Ο.tsutsugamushi was investigated. The genes that were unregulated included macrophage inflammatory proteins l$\alpha$/$\beta$(MIP-l$\alpha$/$\beta$), MIP-2, monocyte chemoattractant protein 1(MCP-1), RANTES (regulated upon activation, normal T-cell expressed and secreted), gamma-interferon-inducible protein 10(IP-10) and TNF-$\alpha$. Peak expression of these chemokines and TNF-$\alpha$ was observed between 1 and 3 h after infection. These responses returned to or approached baseline preinfection levels 6 h after challenge. Semiquantitative reverse transcription (RT)-PCR analysis revealed dramatic Increases during infection in the steady-state levels of mRNA ceding for the inhibitory subunit of NF-kB (IkB$\alpha$), whose transcription is enhanced by binding of NF-kB within the IkB$\alpha$promoter region. Thus, Ο. tsutsugamushi appears to be a stung inducer of chemokines and TNF-$\alpha$ which may significantly contribute to inflammation and tissue damage observed in scrub typhus by attracting and activating phagocytic leukocytes.

• Parasites, Hosts and Diseases
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• v.56 no.4
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• pp.313-324
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• 2018

This article reviews Leptotrombidium deliense, including its discovery and nomenclature, morphological features and identification, life cycle, ecology, relationship with diseases, chromosomes and artificial cultivation. The first record of L. deliense was early in 1922 by Walch. Under the genus Leptotrombidium, there are many sibling species similar to L. deliense, which makes it difficult to differentiate L. deliense from another sibling chigger mites, for example, L. rubellum. The life cycle of the mite (L. deliense) includes 7 stages: egg, deutovum (or prelarva), larva, nymphochrysalis, nymph, imagochrysalis and adult. The mite has a wide geographical distribution with low host specificity, and it often appears in different regions and habitats and on many species of hosts. As a vector species of chigger mite, L. deliense is of great importance in transmitting scrub typhus (tsutsugamushi disease) in many parts of the world, especially in tropical regions of Southeast Asia. The seasonal fluctuation of the mite population varies in different geographical regions. The mite has been successfully cultured in the laboratory, facilitating research on its chromosomes, biochemistry and molecular biology.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.193-201
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• 1998

In Sprague Dawley (SD) rats, antibodies against strains of Orientia tsutsugamushi, Kato, Karp and Gilliam, were produced in order to investigate their longevity and cross-reactivities to their corresponding homologous and heterologous antigens. By immunofluorescence assay (IFA) of IgG and IgM, it was shown that the immunity to the homologous strains persisted at a higher level (longevity of at least 34 weeks with higher IFA titers). On the other hand, the immunity to the heterologous strains persisted at a lower level (longevity of 10 to 34 weeks with lower IFA titers). Since infection with one strain of O. tsutsugamushi does not preclude reinfection with other strains, understanding of the antigenic diversity of O. tsutsugamushi and duration of the immunity to both homologous and heterologous strain is very important in diagnosis of scrub typhus.

• Korean Journal of Adult Nursing
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• v.26 no.1
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• pp.98-106
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• 2014

Purpose: The purpose of this study was to explore the effect of glove changing during surgery for colon cancer on reducing the degree of contamination of surgical gloves. Methods: The randomized posttest control group design was used. Total 72 surgeries of colon cancer in the K University Hospital in Seoul performed by the team of A-Surgeon and B-Scrub nurse were randomly assigned to one of the three groups. Glove changing with single-gloved state was implemented in the Experimental Group I and outer glove changing with double-gloved state was executed in the Experimental Group II. Single-gloved state was carried in the Control Group. Following the surgical procedure, specimens for bacterial culture were collected the from scrub nurse's gloves to compare the degree of contamination among the three groups. Data were analyzed with One-way ANOVA and the Scheff$\acute{e}$'s multiple comparison test. Results: The degrees of contamination of the Experimental Group I and II were significantly lower than that of the Control Group. There was no significant difference between Experimental Group I and II. Conclusion: Glove changing during surgery with either single or double-gloved state is effective in reducing the degree of contamination of surgical gloves, therefore these methods should be utilized in clinical practice.

• Structural Engineering and Mechanics
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• v.68 no.5
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• pp.633-638
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• 2018

One of the important problems in the vehicle design is vehicle handling and stability. Effective parameters which should be considered in the vehicle handling and stability are roll angle, camber angle and scrub radius. In this paper, a planar vehicle model is considered that two right and left suspensions are double wishbone suspension system. For a better analysis of the suspension geometry, a kinestatic model of vehicle is considered which instantaneous kinematic and statics relations are analyzed simultaneously. In this model, suspension geometry is considered completely. In order to optimum design of double wishbones suspension system, a multi-objective genetic algorithm is applied. Three important parameters of suspension including roll angle, camber angle and scrub radius are taken into account as objective functions. Coordinates of suspension hard points are design variables of optimization which optimum values of them, corresponding to each optimum point, are obtained in the optimization process. Pareto solutions for three objective functions are derived. There are important optimum points in these Pareto solutions which each point represents an optimum status in the model. In other words, corresponding to any optimal point, a specific geometric position is determined for the suspension hard points. Each of the obtained points in the Pareto optimization can be selected for a special design purpose by designer to create an optimum condition in the vehicle handling and stability.