• Journal of agricultural medicine and community health
• /
• v.29 no.1
• /
• pp.177-184
• /
• 2004

Objectives: Tsutsugamushi disease is one of the most significant acute febrile illnesses, increasing in frequency of occurrence during the late autumn in rural areas of Korea. Methods: I have conducted a case-control study on 30 cases who had the fever as a chief complaint, then had been ruled out as having the Tsutsugamushi disease. Data was collected retrospectively by review of chart regarding their general characteristics, clinical and laboratory findings, then was analysed by chi-test. Results: Of 30 cases, 16 cases were seropositive and 14 cases were seronegative against O. tsutsugamushi. Of seropositive for tsutsugamushi disease, 56.3% were female; 37.5% were in their seventies; 50.0% were farmers; 62,6% had chances of exposure to fields or mountains. And 75.0% occurred in November. The main symptoms and signs were fever and chill(100.0%), headache(75.0%). weakness and fatigue(93.8%), and eschar(68.8%). The characteristic laboratory findings were elevated AST(50.0%), ALT(62.5%), and abnormal urinalysis(56.3%). On the other hand, of seronegative cases, 57.1% were male; 50.0% were in their fifties; 42.9% were farmers; 57.2% had chances of exposure to fields or mountains. And 71.4% occurred in November. The symptoms and signs were fever and chill(100.0%), headache(85.7%), eschar(64.3%). weakness, fatigue and skin(57.1%). The laboratory findings were elevated AST(71.4%) and ALT(64.3%), and abnormal urinalysis(42.9%). However, there were no significant differences between the seropositive and seronegative cases(P>.05). Conclusions: Acute febrile community inhabitants who have the epidemiological, clinical as well as laboratory features should be focused upon for the early diagnosis and treatment for tsutsugamushi disease whether or not possessing the serological antibody against O. tsutsugamushi.

• Journal of agricultural medicine and community health
• /
• v.19 no.2
• /
• pp.119-128
• /
• 1994

This study was performed on 302 cases of leptospirosis, tsutsugamushi disease and hemorrhagic fever with renal syndrome(HFRS) which occurred in Chonnam(Do) in 1991 through 1993. The results were as follows : 1. 81.8% of the patients with Leptospirosis and 54.5% of the HFRS patients were men while 61.4% of the patients with tsutsugamushi disease were women. 2. Most patients lived in rural areas(Gun), their educational level was elementary School or lower and their occupations were either farmer or jobless. 3. Peak ages were 40s for leptospirosis(36.4%) and 50s for tsutsugamushi disease and HFRS(32.9% and 36.4% respectively). 4. The high incidence areas of tsutsugamushi disease were northern, eastern and a diagonal line, from northeast to southwest, of the Chonnam area, and these are consistent with a mountainous district. 5. In monthly distribution leptospirosis was higher in Sep. and Oct., and tsutsugamushi disease and HFRS were higher in Oct. and Nov. 6. The first case is occurring and the last case shows up later than in past years.

• Korean Journal of Veterinary Service
• /
• v.35 no.3
• /
• pp.183-189
• /
• 2012

Tsutsugamushi disease or scrub typhus cause by Orientia tsutsugamushi is an endemic disease in Korea. Chigger mites and field rodents play roles in transmission of the disease by the vector and host of the agent. The purpose of this study is to investigate the density of the chigger mites and field rodents due to environmental factors such as temperature, relative humidity, soil thickness and the various vegetations to the 9 field rodent collection sites. The total 62 field rodents was captured by the Sherman collapsible traps from April to October 2009 at the Jangseong of Jeonnam Province, Korea. The trapping rate of the field rodents by the different collecting sites was dominant at subside storage water (24%), bush near by dam (22%), bank around field (20%), followed by 18% of grassy field and surround cattle shed. The distribution of chigger mites by the different collecting sites was the highest at Bush near by dam (28.7%). And the sites of subside storage water, bank around field and surround cattle shed were 20.4%, 18.8%, 16.4%, respectively. On the other hand the collecting sites of stream bank and ridges between rice paddies were not collected. The temperature to the collecting sites was showed $24.1^{\circ}C$ in June and $24.2^{\circ}C$ in October which was higher than April ($10.6^{\circ}C$), whereas lower than May ($25.3^{\circ}C$) and September ($26.8^{\circ}C$). The highest number of mites was collected at $24.2^{\circ}C$ and 46.6% relative humidity in October. The chigger mites and field rodents were highly collected between 18 and 24% at the sites where are loosely in the superficial layers of the soil from 8.0 cm to 10.2 cm. Total 25 species of vegetation were distributed at the collecting sites. In the present study, strong evidence was found that bank around field and grassy field were provided for the prevalence sites of tsutsugamushi disease.

• Korean journal of applied entomology
• /
• v.47 no.3
• /
• pp.287-292
• /
• 2008

Repellent and acaricidal activities of eucalyptus oil, permethrin, and DEET against Leptotrombidium pallidum larvae, which are a vector transmitting tsutsugamushi disease, were evaluated under laboratory conditions using a filter paper impregnated method. The $LD_{50}$ values of eucalyptus oil and DEET were 0.025 and 0.018 $mg/cm^2$, respectively while that of permethrin was higher than 0.2 $mg/cm^2$. In the repellency test of these materials at 6.14 $mg/cm^2$, eucalyptus oil gave complete repellency, and the larvae crossed the treated zone killed. But permethrin showed 60% repellency at 9.20 $mg/cm^2$ and the mites croosed the zone were not killed. The percent repellency of DEET at 0.53 $mg/cm^2$ was 8.3 and 2.8 times higher than that of permethrin and eucalyptus oil, respectively. The acaricidal activities of emulsifiable concentrates-pump sprayers containing the eucalyptus oil as an active ingredient were assayed. The emulsifiable concentrates containing 1% and 3% eucalyptus oil showed weak mortality at 1 hour after treatment, while all ones containing more than 6% oil produced 100% activity against L. pallidum larvae. The mortality also increased as exposure time to the concentrates increase. These results suggest that the potential of eucalyptus oil highly expected to be used as a control or repellent agent against L. pallidum larvae may be very high.

• Pediatric Infection and Vaccine
• /
• v.12 no.2
• /
• pp.101-107
• /
• 2005

Purpose : We evaluated the C-reactive protein(CRP), white blood cell(WBC) and neutrophil levels in the various infectious diseases in a single hospital. Methods : A total of 640 medical records of children with infectious diseases such as bacterial meningitis(19 cases), acute pyelonephritis(55 cases), measles(253 cases), chicken pox (38 cases), mycoplasma pneumonia(160 cases), tsutsugamushi disease(39 cases) and Kawasaki disease(152 cases) admitted to The Catholic University of Korea, Daejeon St. Mary's hospital from 1996 to 2002 were retrospectively analyzed. Results : The mean CRP level was $17.9{\pm}6.4mg/dL$ in bacterial meningitis, $9.1{\pm}5.6mg/dL$ in Kawasaki disease, and $8.1{\pm}3.3mg/dL$ in acute pyelonephritis. In the mycoplasma pneumonia and tsutsugamush disease group(atypical bacterial group), the CRP level was $3.2{\pm}2.5mg/dL$, and $1.0{\pm}0.8mg/dL$ in the viral diseases group(measles and chicken pox). There were also significant differences for the WBC count and neutrophil differential between the 3 infectious groups with higher level in the bacterial infections group($15,600{\pm}6,100/mm^3$, $62{\pm}21%$) than in the atypical bacterial infections and in the viral infections group($9,600{\pm}3,300mm^3$, $57{\pm}11%$ and $7,300{\pm}2,900/mm^3$, $49{\pm}16%$, respectively). The inflammatory indices in Kawasaki disease were like those of bacterial infections. There was a correlation between CRP level and WBC or neutrophil count in the bacterial infections and Kawasaki disease groups. Conclusion : The CRP, WBC and neutrophil levels showed a clear difference between the infectious diseases according to causative agents. The WBC and neutrophil level was different according to age in measles and mycoplasma pneumonia. There was a correlation between CRP level and WBC or neutrophil count in the bacterial infections and Kawasaki disease groups.

• Tuberculosis and Respiratory Diseases
• /
• v.66 no.2
• /
• pp.116-121
• /
• 2009

Background: Tsutsugamushi, leptospirosis and hemorrhagic fever with renal syndrome (HFRS) are the prevalent diseases among the acute febrile illnesses in Korea. Pulmonary involvement in the patients with these diseases remains poorly recognized in endemic regions, and this is despite reports of recent outbreaks and epidemic episodes. Pulmonary involvement and a higher CRP level as clinical manifestations show a more severe form of infection. The aim of this study is to analyze the correlation of pulmonary involvement and the CRP level in patients with acute febrile illnesses. Methods: We retrospectively reviewed the clinical records of 105 patients who were diagnosed with tsutsugamushi, HFRS and leptospirosis from January 2002 to May 2008 in Chuncheon Sacred Heart Hospital. The radiographic images were retrospectively analyzed by two radiologists. We analyzed the pulmonary complications of the patients with these febrile diseases and we checked the CRP level at admission. Results: The study included 105 patients who were diagnosed with febrile diseases. Of these patients, 32 patients had hantaan, 10 patients had leptospirosis and 63 patients had tsutsugamushi disease. 42 (40%) patients had pulmonary complications, 20 patients had pulmonary edema, 20 patients had pleural effusion and 2 patients had interstitial pneumonitis. The patients with pulmonary involvement showed a more severe form of infection and a higher CRP level than that of those patients without pulmonary involvement (p=0.0073). Conclusion: Pulmonary involvement in patients with acute febrile diseases might be correlated with a higher CRP level. Identification of this factor on admission might provide useful selection criteria for the patients who need early intensive care.

• Spatial Information Research
• /
• v.20 no.2
• /
• pp.13-24
• /
• 2012

To prevent the damage to human health by climate change, vulnerability assessment should be conducted for establishment of adaptation strategies. In this study, vulnerability assessment was conducted to provide information about vulnerable area for making adaptation policy. vulnerability assessment for human health was divided into three categories; extreme heat, ozone, and epidemic disease. To assess vulnerability, suitable indicators were selected by three criteria; sensitivity, adaptive capacity, and exposure, spatial data of indicators were prepared and processed using GIS technique. As a result, high vulnerability to extreme heat was shown in the low land regions of southern part. And vulnerability to harmful ozone was high in the surrounding area of Dae-gu basin and metropolitan area with a number of automobiles. Vulnerability of malaria and tsutsugamushi disease have a region-specific property. They were high in the vicinity of the Dimilitarized zone and south-western plain, respectively. In general, vulnerability of human health was increased in the future time. Vulnerable area was extended from south to central regions and from plain to low mountainous regions. For assessing vulnerability with high accuracy, it is necessary to prepare more related indicators and consider weight of indicators and use climate prediction data based on the newly released scenario when assessing vulnerability.

• Journal of Environmental Health Sciences
• /
• v.42 no.1
• /
• pp.41-52
• /
• 2016

Objectives: Scrub typhus is one of the most prevalent vector-borne diseases. It is caused by Orientia tsutsugamushi, which is transmitted when people are bitten by infected chigger mites. This study aims at quantifying the association between the incidence of scrub typhus and meteorological factors in Jeollabuk-do Province over the period 2001-2015. Methods: Reported cases of scrub typhus were collected from the website of the Disease Web Statistical System supported by the Korea Centers for Disease Control and Prevention (KCDC). Simultaneous meteorological data, including temperature, rainfall, relative humidity, and sunshine duration were collected from the website of the National Climate Data Service System by the Korea Meteorological Administration. Correlation and regression analyses were applied to identify the association between the incidence of scrub typhus and meteorological factors. Results: The general epidemiological characteristics of scrub typhus in Jeollabuk-do Province were similar to those nationwide for sex, age, and geographical distribution. However, the annual incidence rate (i.e., cases per 100,000) of scrub typhus in Jeollabuk-do Province was approximately four times higher than all Korea's 0.9. The number of total cases was the highest proportion at 13.3% in Jeonbuk compared to other regions in Korea. The results of correlation analysis showed that there were significant correlations between annual cases of scrub typhus and monthly data for meteorological factors such as temperature and relative humidity in late spring and summer, especially in the case of temperature in May and June. The results of regression analysis showed that determining factors in the regression equation explaining the incidence of scrub typhus reached 46.2% and 43.5% in May and June. Using the regression equation, each 1oC rise in the monthly mean temperature in May or June may lead to an increase of 38 patients with scrub typhus compared to the annual mean of incidence cases in Jeollabuk-do Province. Conclusion: The result of our novel attempts provided rational evidence that meteorological factors are associated with the occurrence of scrub typhus in Jeollabuk-do. It should therefore be necessary to observe the trends and predict patterns of scrub typhus transmission in relation to global-scale climate change. Also, action is urgently needed in all areas, especially critical regions, toward taking steps to come up with preventive measures against scrub typhus transmission.

• Korean Journal of Veterinary Service
• /
• v.26 no.3
• /
• pp.203-214
• /
• 2003

Scrub typhus and murine typhus are common endemic febrile illness in the fall in Korea. Scrub typhus is caused by Orientia tsutsugomushi, murine typhus is caused by Rickettsia typhi. Trombiculid mites are known as both the vector and the reservoir host of O tsutsugamushi, the mites which transmit O tsutsugomushi have been reported to be Leptotrombidium pallidum and L scutellare. The author carried out an epidemiological study of scrub typhus and murine typhus in Kyodong-Myeon, Kanghwa-Gun, Incheon in relation to the residents and the host rodents, such as their distribution, seroepidemiology, and population density of chigger mites. 1. Out of 900 residents, 33(3.7%) showed positive reaction to O tsutsugamushi, 24(2.7%) to R typhi. 2. In the seropositives to O tsutsugamushi or R typhi, between the sixties and the seventies of the age were dominant. 3. In the seropositives to O tsutsugamushi serotypically Gilliam was dominant. 4. Among the total 42 field rodents trapped by the sherman traps, 18 rodents were Apodemus agrarius(42.9%), 13 rodents were Crocidura lasiura(31.0%), 5 rodents were Musmusculus(11.9%), 2 rodents(4.8%) were Crocidura suaveolens, Rattus norvegicus, Tscherskia triton, respectively. 5. Out of 42 field rodents, 25 were parasitized by 4,419 chigger mites, showing 59.5% of the infestation rate and 98.8 of the chigger index. L pallidum parasitized in A agrarius, C lasiura, M musculus, R norvegicus and T triton, and L scutellare parasitized only C lasiura. 6. Antibodies in the sera of field rodents against O tsutsugamushi and R typhi were investigated by indirect immunofluorescent antibody technique. Positive rate of antibody against O tsutsugamushi were 11.9(5 of 42) and all of the positive is A agrarius. Antibody against R typhi was not detected. These results might provide the basic information for the management of scrub typhus and murine typhus in Kyodong-myeon, where the epidemiological studies on scrub typhus and murine typhus was not carried out enough.

• Parasites, Hosts and Diseases
• /
• v.33 no.1
• /
• pp.27-36
• /
• 1995

Comparative epidemiological studies on vector reservoir animals of tsutsugamushi disease were carried out in between south coast (the highest endemic) areas and east coast flow endemicl areas in October 1993. Fauna of field rodents and their population densities were not different between two areas. Antibody positive rate of Apodemus agrarius sera was higher in east coast (43.2% in south coast and 63.6% in east coast). High correlation (r = 0.87) was shown between antibody positive rate of A. osrwiur sera and population density of the vector mites (Leptotrombidium scutellare and 1. pnllidunl). L. scutellare was predominant in south coast, showing 110.6 chigger index (74.9% of the total chiggersl , whereas L. pcllidum was predominant in east coast, showing 126.3 chigger index (60.4% of the total). As higher population density of 1. scutellare was found in south coast where the prevalence rate of tsutsugamushi disease is the highest, it is believed that L. scutellare is more important vector species than L. pallidum which may result from more frequent vector-human contact.