Publications by authors named "Kyu-Sik Chang"

The compounds 1,8-cineole and zerumbone (ZER) from the Cyperus rotundus rhizome along with another 11 previously identified rhizome essential oil constituents and α-humulene, which lacks the only carbonyl group present in ZER, as well as binary mixtures of ZER and seven active compounds were tested for repellency to male B. germanica. The results were compared to N,N-diethyl-3-methylbenzamide (deet).

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Zika virus (ZIKV) is an arthropod-borne virus mainly transmitted by species. A total of nine of the 16 imported ZIKV reported cases during the mosquito season in the Republic of Korea (ROK), following the return of local nationals from foreign ZIKV endemic countries, were surveyed for . Surveillance and vector control of , a potential vector of ZIKV, and related species are critical for reducing the potential for autochthonous transmission in the ROK.

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Understanding the mechanisms of insecticide resistance to vector mosquitoes is critical for the implementation of effective control measures. A nulliparous susceptible (KSCP) laboratory colony and two field strains from Paju (PAJ) and Jeonju (JEO) Korea were evaluated for susceptibility to five pesticides by microapplication techniques. Unfed PAJ and JEO females demonstrated increased resistance compared to unfed KSCP females, respectively.

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Article Synopsis
  • Ticks are crucial in spreading arboviruses linked to emerging infectious diseases, impacting human, animal, and wildlife health significantly.
  • A study in the Republic of Korea collected over 21,000 ticks from various regions and examined them for pathogens like SFTSV and TBEV, identifying a prevalence of 0.95 and 0.43 respectively.
  • The findings highlight the importance of ongoing surveillance of ticks and tick-borne diseases to better understand and manage potential health threats in the region.
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Background: As a result of the reintroduction of malaria in the Republic of Korea (ROK) in 1993 and the threat to military and civilian populations, the Korea Military National Defense (MND) increased emphasis on vector control in 2012 at ROK Army (ROKA) installations located near the DMZ, while decreasing chemoprophylaxis, fearing potential drug resistance. Mosquito surveillance demonstrated a need for continuous monitoring of disease patterns among ROKA soldiers and vector malaria infection rates to ensure positive outcomes.

Methods: Anopheles spp.

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Japanese encephalitis virus (JEV) causes significant viral encephalitis and is distributed throughout the Asian countries. The virus is known to be transmitted by Culex tritaeniorhynchus, which mainly breeds in rice paddies in Korea. In this study, we investigated the presence of other mosquito species that can transmit JEV as a second or regional vector.

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To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0.

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An assessment was made of the toxicity of 12 insecticides and three essential oils as well as Bacillus thuringiensis subsp. israelensis (Bti) alone or in combination with the oil major constituents (E)-anethole (AN), (E) -cinnamaldehyde (CA), and eugenol (EU; 1:1 ratio) to third instars of bamboo forest-collected Aedes albopictus (Skuse) and rice paddy field-collected Anopheles sinensis Wiedemann. An.

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Transovarial transmission of Orientia tsutsugamushi in colonies of Leptotrombidium palpale was studied in the parent and F1 and F2 generations. Both transovarial transmission and filial infection rates were 100% in the parent and F1 generations of Leptotrombidium palpale. The filial infection rate in the F1 generation was 100%, but it declined to 94.

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Objectives: Over 20% of all malaria cases reported annually in the Republic of Korea (ROK) occur in Paju, Gyeonggi Province. Vector control for malaria management is essential, but the insecticide resistance of the vector, Anopheles mosquitoes, has been a major obstacle in implementing effective control. In this study, the insecticide resistance of the vector mosquitoes was evaluated and compared with that of vector mosquitoes collected from the same locality in 2001 and 2009.

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The toxicities of 10 insecticides were examined against late third instar Culex tritaeniorhynchus Giles (Diptera: Culicidae) using the direct-contact mortality bioassay. Six geospatially-distant field mosquitoes were collected from Chuncheon-si, Hwaseong, Seosan. Jeonju, Daegu, and Busan in the Republic of Korea.

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Leptotrombidium pallidum (Nagoya, Miyagawa, Mitamura & Tamiya) is a primary vector of Orientia tsutsugamushi (Hyashi), the causative agent of scrub typhus. An assessment is made of the repellency to L. pallidum larvae (chiggers) of cassia bark, eucalyptus, and star anise oils and major constituents (E)-cinnamaldehyde, 1,8-cineole, and (E)-anethole of the corresponding oils.

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Vivax malaria is a significant military and civilian health threat in northern Republic of Korea (ROK). Mosquito collections were performed at two ROK army installations, Paju near the demilitarized zone (DMZ) using black light traps in 2011. The DMZ, a 4 km wide border, is the northernmost point of the ROK and separates the ROK from the Democratic People's Republic of Korea (DPRK).

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We assessed the toxicity of 17 steam distillate constituents of Cyperus rotundus (L.) rhizome, another seven known compounds of C. rotundus rhizome, and 14 structurally related compounds to females from an insecticide-susceptible KSS strain and two field-collected SEL and DJN colonies of Blattella germanica (L.

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The number of Plasmodium vivax malaria cases in the Republic of Korea (ROK) in 2008 was 1009, a 54.2% decrease on the previous year. It then resurged to 1317 cases in 2009 (30.

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The larvicidal activity of 11 Myrtaceae essential oils and their constituents was evaluated against Aedes aegypti L. Of the 11, Melaleuca linariifolia Sm., Melaleuca dissitiflora F.

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The repellency of Zanthoxylum armatum seed oil (ZA-SO), alone or in combination with vanillin (VA), its six major constituents, and another four major previously known Zanthoxylum piperitum fruit oil constituents, as well as aerosol products containing 5 or 10% ZA-SO and 5% VA, was evaluated against female Aedes aegypti in laboratory and field studies. Results were then compared with those of N,N-diethyl-3-methylbenzamide (DEET) as a standard. Hand in cage laboratory tests showed that 0.

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Background: Culex pipiens molestus Forskal has been reported as a dominant species in underground structures of urban areas in the Republic of Korea (ROK) during all seasons and becomes bothersome to humans in late autumn and winter. Most Cx. pipiens molestus in septic tanks are controlled in the ROK using larvicides such as Bt and IGR.

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We investigated the toxicity of (-)-asarinin, α-asarone, methyleugenol, pellitorine, and pentadecane identified in Asarum heterotropoides root to third instar larvae from insecticide-susceptible Culex pipiens pallens (KS-CP strain), Aedes aegypti, and Ochlerotatus togoi as well as field-collected C. p. pallens (DJ-CP colony), identified by polymerase chain reaction.

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Plasmodium vivax malaria, which re-emerged in the Republic of Korea (ROK) in 1993, had decreased since 2001. However, case numbers began to increase again in 2005. The number of cases rose 54.

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Anopheles sinensis Wiedemann (63.3%) was the most abundant Anopheles mosquito captured at cowshed resting collections in malaria high-risk areas (northern Gyeonggi Province) near the demilitarized zone (DMZ) in Korea during 2005, followed by Anopheles kleini Rueda (24.7%) and Anopheles pullus M.

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Patch and skin bioassays were used in laboratory and indoor tests to evaluate the repellency of (E)-cinnamaldehyde, identified in Cinnamomum cassia Blume bark and essential oil, and a cream containing 5% (w/w) cassia oil against Aedes aegypti (L.) females. Results were compared with those of a known C.

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The repellency of fennel (Foeniculum vulgare Miller)-containing products (5% aerosol and 8% cream) against mosquitoes was compared with those of citronella oil, geranium oil and deet, as well as three commercial repellents, Baby Keeper cream containing IR3535, MeiMei cream containing citronella and geranium oils, and Repellan S aerosol containing 19% N,N-diethyl-m-toluamide (deet) under laboratory and field conditions. In a laboratory study with female Aedes aegypti (L), fennel oil exhibited good repellency in a release-in-cage test and repellency in skin and patch tests of the oil was comparable with those of citronella and geranium oils. In paddy field tests with five human volunteers, 5% and 8% fennel oil-containing aerosol and cream produced 84% and 70% repellency, respectively, at 90 min after exposure, whereas Baby Keeper cream and MeiMei cream gave 71% and 57% repellency at 90 min after exposure, respectively, and Repellan S aerosol gave 89% repellency at 210 min.

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The repellent activity of materials derived from the methanol extract of fruits from Foeniculum vulgareagainst hungry Aedes aegypti females was examined using skin and patch tests and compared with that of the commercial N,N-diethyl-m-toluamide (deet) and (Z)-9-octadecenoic acid. The biologically active constituents of the Foeniculum fruits were characterized as (+)-fenchone and (E)-9-octadecenoic acid by spectroscopic analyses. Responses varied according to compound, dose, and exposure time.

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The insecticidal activities of materials derived from the fruit of star anise, Illicium verum, against adults of Blattella germanica were examined by direct contact application and fumigation methods, and compared with those of DDVP, deltamethrin and hydramethylnon. The biologically active constituent of the Illicium fruit was characterized as the phenylpropene, (E)-anethole, by spectroscopic analysis. In a filter paper diffusion test with females, (E)-anethole caused 80.

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