• Title/Summary/Keyword: epidemic disease

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AN SIRS EPIDEMIC MODEL ON A DISPERSIVE POPULATION

  • Ghosh, Asit K.;Chattopadhyay, J.;Tapaswi, P.K.
    • Journal of applied mathematics & informatics
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    • v.7 no.3
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    • pp.925-940
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    • 2000
  • The spatial spread of a disease in an SIRS epidemic model with immunity imparted by subclinical infection on a population has been considered. The incidence rate of infection and the rate of immunization are both of nonlinear type. The dynamics of the infectious disease and its endemicity in local and global sense have been investigated.

EXISTENCE AND UNIQUENESS OF ENDEMIC STATES FOR AN EPIDEMIC MODEL WITH EXTERNAL FORCE OF INFECTION

  • Cha, Young-Joon
    • 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.

A DELAYED SIR EPIDEMIC MODEL WITH NONLINEAR INCIDENCE RATE AND PULSE VACCINATION

  • Du, Yanke;Xu, Rui
    • Journal of applied mathematics & informatics
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    • v.28 no.5_6
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    • pp.1089-1099
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    • 2010
  • An SIR epidemic model with pulse vaccination and time delay describing infection period is investigated. The global attractiveness of the infection-free periodic solution is discussed, and sufficient condition is obtained for the permanence of the system. Our results indicate that a large vaccination rate or a short period of pulsing leads to the eradication of the disease.

Introduction of Phylodynamics for Controlling the HIV/AIDS Epidemic in Korea

  • Bae, Jong-Myon
    • Journal of Preventive Medicine and Public Health
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    • v.51 no.6
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    • pp.326-328
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    • 2018
  • As over 1000 new cases of HIV/AIDS occur in Korea annually, preventive health programs against HIV/AIDS are urgently needed. Since phylodynamic studies have been suggested as a way to understand how infectious diseases are transmitted and evolve, phylodynamic inferences can be a useful tool for HIV/AIDS research. In particular, phylodynamic models are helpful for dating the origins of an epidemic and estimating its basic reproduction number. Thus, the introduction of phylodynamics would be a highly valuable step towards controlling the HIV/AIDS epidemic in Korea.

Study on Epidemic Warm Diseases with dampness of "OnByeongJoByeon" ("온병조변(溫病條辨)" 습류온병(濕類溫病)에 대한 고찰)

  • Park, Mi Sun;Kim, Yeong Mok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.6
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    • pp.803-811
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    • 2012
  • Oriental Medicine always attach great importance to the damp diseases. Dampness is related with many organs and many clinical diseases. The cause and the location of the damp disease, nature of the symptoms, combination with other pathogenic factors are very diverse. This article analyzed the concept, cause of disease, pathogenesis, characteristic of symptoms, treatment method and prescriptions of Epidemic Warm Diseases of dampness syndrome and cases of dampness-heat diseases based on the theories of Epidemic Warm Diseases and found that theories of Epidemic Warm Diseases have very wide area of application. Dampness is classified into cold-dampness and dampness-heat by combination of heat or cold. The dampness syndrome is related with organs such as lung, spleen, kidney, triple energizers and bladder, and affects liver and heart. The basic treatment methods are dispelling dampness turbidity and diffusing qi movement. The detail treatment methods are spreading lung qi with lightness and resolving dampness and excreting turbidity in upper energizer, opening and dipping down with pungent-bitter and diffusing qi movement and strengthening the spleen and stomach in the middle energizer, draining dampness with bland in the lower energizer. Warming Yang is the main method of treatment for cold-dampness and clearing heat is for dampness-heat with the assistant methods such as resolving dampness and promoting the flow of qi. 5. Acute fever, virus diseases, epidemic diseases among modern diseases are much related with the dampness-heat syndrome.

A Study on the Composition of Shanghanluntiaobian(傷寒論條辨) (방유집(方有執)의 『상한론조변(傷寒論條辨)』 조문(條文) 구성에 대한 고찰(考察))

  • Ahn, Jin-hee;Kim, Hye-il;Jeong, Chang-hyun;Jang, Woo-chang;Baik, You-sang
    • Journal of Korean Medical classics
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    • v.29 no.1
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    • pp.1-15
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    • 2016
  • Objectives : The purpose of this study is to investigate the method of setting up logic and estimate Fang Youzhi's work through Shanghanluntiaobian. Methods : Wang Shuhe's old edition Shanghanlun and Fang Youzhi's Shanghanluntiaobian were compared and several essential provisions were analyzed and addressed the positive and negative aspects of Fang Youzhi's revising old edition Shanghanlun mixed bamboo tablets. Results : Fang Youzhi's changing Bianmaifa("辨脈法") and Pingmaifa("平脈法") and placement Bianchishiyemaizhengbingzhi chapter after Liujingbingmaizhengbingzhi for discriminating convulsion dampness summer heat stroke from febrile diseases is appropriate. Fang Youzhi's deletion Shanghanli("傷寒例") chapter that has a guiding characteristics shows his editorial policy. Fang Youzhi's addition Bianwenbingfengwenzabingmaizhengbingzhi chapter is for discriminating febrile disease from epidemic febrile disease wind warmth syndrome miscellaneous disease and it indicates Shanghanlun is a book of treatment after differentiation of syndromes containing epidemic febrile disease and miscellaneous disease. Through Fang Youzhi's revising method I can see several positive aspects. First he tried to refine the logic of the content of Shanghanlun and accord with an actual situation. Second he shows Shanghanlun is a book of treatment after differentiation of syndromes containing epidemic febrile disease and miscellaneous disease and tried to see Shanghanlun clearly. A criticism of the Preserving Old Edition Shanghanlun group could interrupt flexibility and creative thinking reading Shanghanlun and a criticism to the Sangangdingli Principles of the several exegetists is a productive criticism because medicine treats human being so it cannot be completed by a logic. Conclusions : All of these processes are Fang Youzhi's endeavour for strengthening the system and logicality of the old edition Shanghanlun and it is meaningful to show a method to read Shanghanlun to beginners.

The Epidemiologic Pattern of Tsutsugamushi Epidemic in Chollanamdo Province in 1991 (1991년 전남지방의 쭈쭈가무시병 유행에 관한 연구)

  • Han, Kwang-Il;Moon, Gang;Choi, Jin-Su
    • Journal of agricultural medicine and community health
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    • v.17 no.2
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    • pp.93-102
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    • 1992
  • The epidemic of tsutsugamushi disease, along with hemorrhagic fever with renal syndrome(HFRS) and leptospirosis, has been ingrowing concern as it occupies a considerable proportion of the so-called seasonal febrile illnesses in autumn in Korea. This study was conducted to describe certain epidemiologic characteristics of the reported cases of the tsutsugamushi epidemic in Chollanamdo province in 1991. The findings could be summarized as follows: 1. Among three seasonal febrile illnesses in Autumn, tsutsugamushi disease occupied 91.9 percent of whole serologically confirmed cases. 2. Male-female sex ratio was 1 : 1.8. Majority of cases (77.4% in men, 65.1% in female) were in older age group (>=50 year of age). 3. Date of disease onset were distributed between late September and November. The 67.4% of cases were developed from October 21 to November 10, 1991. 4. The 41.5% of cases were reported from southern maritime districts. Reported dates of index cases and median cases were earliest in inland districts followed by southern maritime and latest in western maritime districts. 5. Most frequently reported clinical symptoms were chill (100%), high fever (100%), headache (81.7%), and skin eruption (70.4%).

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Epidemiologic characteristics of malaria in non-malarious area, Jeollabuk-do, Korea in 2000

  • Kim, Myung-Bin
    • Parasites, Hosts and Diseases
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    • v.39 no.3
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    • pp.223-226
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    • 2001
  • In South Korea, the north border area has been under vivax malaria epidemic since 1993. However, Jeollabuk-do, which is about 300 kms from the border, has not experienced the same epidemic. 1 investigated a total of 58 notified cases of malaria in Jeollabuk-do in the year 2000. All of the cases had an exposure history in the epidemic area. Among them were 49 ex-soldiers, 3 soldiers who served near the border area and 6 civilians who traveled there. The causal agent of all cases was Plasmodium vivax. Except the civilians, the soldiers and ex-soldiers were aged in their twenty's. In the present study, the incubation period was from 6 to 520 days with a median of 157 days, and the latent onset type (92%) was more prevalent than the early onset type. illness onset of most cases (86%) peaked during the summer season (June to September) despite of variable incubation periods. The time lag for diagnosis ranged from 2 to 42 days with a median of 11 days. Jeollabuk-do has not been an area of epidemic untill now, but incidences have been increasing annually since 1996. In Jeollabuk-do, early diagnosis and treatment can be a feasible disease control measure to prevent spreading from the epidemic area.

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Disease survey on bacterial leaf blight of rice in Chun Nam province (전남지방에 있어서의 수도백엽고병 발생실태조사)

  • Lee K. H.;Chung H. W.;Lee W. K.;Lee S. C.;Kim Y. S.
    • Korean journal of applied entomology
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    • v.4
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    • pp.33-38
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    • 1965
  • 1. This survey was conducted to make a basis for the cause of severe epidemic and disease control to the losses due to bacterial leaf blight of rice in Chun-Nam rice paddy field areas in the first part of October in 1965. The severe epidemic areas were included Taijun-Myun, Tamyang-Eup, riverside in Youngsanpo and seaside in the suburbs of Mokpo. 2. A drought in the period of rice transplanting and flooding due to a heavy rain in July were resulted reasonable weather conditions that the disease occurred more early and severe epidemic. 3. In Tamyang area, frist outbreak of the disease was on the middle part of July in the paddy flooded after heavy rainfall of the first fart of July. It is recognized to farmers that the disease is known as a now serious one. 4. The more date of transplanting is followed, the more serious damage is happened and especially, in the paddy field flooded, too. 5. Flooded areas showed more serious epidemic. 6. Varietal difference to the disease was surely noticed, and Kumnampoong and Chunbonwuk were susceptible, whereas Norin 6 was resistant. 7. Damage was occurred more in plant paddy area than tile slopping paddy area. 8. Fallow paddy field was more serious than the field using double cropping a year. 9. Moist and semimoist paddy field were more serious damage, while light damage in dry paddy field. 10. Near part of flood gate for drainage of submerge paddy was more serious damage than inside part of the field. 11. Soft type is often seen in the mode of the disease occurrences. 12. The most farmers insisted that dropping water is caused to promote disease dissemination when disease occurred.

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MODELING AND ANALYSIS OF AN EPIDEMIC MODEL WITH CLASSICAL KERMACK-MCKENDRICK INCIDENCE RATE UNDER TREATMENT

  • Kar, T.K.;Batabyal, Ashim;Agarwal, R.P.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.14 no.1
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    • pp.1-16
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    • 2010
  • An epidemic model with Classical Kermack-Mckendrick incidence rate under a limited resource for treatment is proposed to understand the effect of the capacity for treatment. We have assumed that treatment function is strictly increasing function of infective individuals and becomes constant when the number of infective is very large. Existence and stability of the disease free and endemic equilibrium are investigated, boundedness of the solutions are shown. Even in this simple version of the model, backward bifurcation and multiple epidemic steady states can be observed with some sets of parameter values. Hopf-bifurcation analyses are given and numerical examples are provided to help understanding.