• Title/Summary/Keyword: Anopheles

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Analysis of Pyrethroid Resistance Allele in Malaria Vector Anopheles sinensis from Malaria High-risk Area (말라리아 위험지역에서 채집된 말라리아 매개모기 Anopheles sinensis의 피레스로이드계 저항성 대립형질 분석)

  • Choi, Kwang Shik;Lee, Seung-Yeol;Hwang, Do-Un;Kim, Heung-Chul;Chang, Kyu-Sik;Jung, Hee-Young
    • The Korean Journal of Pesticide Science
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    • v.20 no.4
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    • pp.286-292
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    • 2016
  • Malaria is mainly transmitted by Anopheles sinensis which is dominant species in malaria high-risk area, northern part of Gyeonggi province in Korea. Pyrethroid insecticide is used for malaria vector, An. sinensis in Korea and the previous investigation consistently reported insecticide resistance from the vector. This study investigated insecticide susceptible and resistant alleles from An. sinensis and the status of malaria vector control in malaria high-risk area. For the study, An. sinensis collected from Paju, Gimpo and Ganghwa were sequenced for kdr detection. In Paju, there was no homozygous susceptibility and all of tested samples had homozygous or heterozygous resistance. There were 6.7% for susceptible homozygosity and 93.3% for resistant homozygosity or heterozygosity in Gimpo. Furthermore, the percentages of homozygous susceptibility and homozygous or heterozygous resistance in Ganghwa were 5.7% and 94.3% respectively. The results showed that the frequency of the insecticide resistance from An. sinensis in malaria high-risk area were increased much more than the previous investigation. Hence, this study suggests that malaria vector control programs should have to be prepared for the management of pyrethroid insecticide resistance.

Epidemiological Study of Malaria Outbreak in the Northern-part of Kyonggi-do (경기북부지역의 말라리아에 관한 역학적 연구)

  • 박용배;홍해근;방선재;임준래;문혜경
    • Journal of environmental and Sanitary engineering
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    • v.15 no.1
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    • pp.46-53
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    • 2000
  • Korea has been free of malaria since the mid-1970s. Since the first malaria case was reported in 1993, the incidence of indigenous malaria has increased yearly, In this study, we planned to understand of malaria outbreak in the northern part of kyonggido. The subjects were a civilians except korean soldiers in the northern part of Kyonggido and the number of civilian malaria cases was 254 in 1997, 677 in 1998, 772 in 1999. The collected rates of Anopheles sinenis in 11 county from May to October were 10.1% to 85.1% and the monthly collected rates at June was highest. The incidence of malaria antibody according to the county was 5.4% in Paju-shi Tanhyun-myun 4.9% in Kapyong-gun Ha-myun, 3.0% in Yonchon-gun Yonchon-eup. etc. At the result of relationship between civilian cases and No. of A. sinenis, envionmental factor were showed high association.

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Malaria transmission potential by Anopheles sinensis in the Republic of Korea

  • Lee, Hee-Il;Lee, Jong-Soo;Shin, E-Hyun;Lee, Won-Ja;Kim, Yoon-Young;Lee, Kyung-Ro
    • Parasites, Hosts and Diseases
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    • v.39 no.2
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    • pp.185-192
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    • 2001
  • To evaluate the factors that determine the transmission level of vivax malaria using vectorial capacity, entomological surveys were conducted from .lune to August, 2000. From 6 nights of human-bait collection in Paju, the human biting rate (ma) was counted as 87.5 bites/man/night. The parity of Anopheles sinensis from human baiting collections fluctuated from 41% to 71% (average 48.8%) of which the rate gradually increased as time passed on: 35.2% in Jun. ; 55.0% in July; 66.2% in Aug. From this proportion of parous, we could estimate the probability of daily survival rate of An. sinensis to be 0.79 assumed with 3 days gonotrophic cycle and the expectancy of infective life through 11 days could be defined as 0.073. Blood meal analysis was performed using ELISA to determine the blood meal source. Only 0.8% of blood meals were from human hosts. We could conclude that An. sinensis is highly zoophilic (cow 61.8%) Malaria is highly unstable (stability index < 0.5) in this area. From these data, vectorial capacity VC) was determined to be 0.081. In spite of a high human biting rate (ma), malaria transmission potential is very low due to a low human blood index. Therefore, we could conclude that malaria transmission by An. sinensis is resulted by high population density, not by high transmission potential. For this reason, we need more effort to decrease vector population and vector-human contact to eradicate malaria in Korea.

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Studies on Anopheles sinensis, the vector species of vivax malaria in Korea

  • REE Han-Il
    • Parasites, Hosts and Diseases
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    • v.43 no.3 s.135
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    • pp.75-92
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    • 2005
  • Extensive previous studies on taxonomy, behavior/bionomics and control of Anopheles sinensis are reviewed and summarized. Recent molecular identification revealed that the population of An. sinensis complex includes An. sinensis, An. pullus, An. lesteri and at least two new species, and An. yatsushiroensis is synonmy of An. pullus. An. sinensis is the main vector specie of vivax malaria in Korea. Larvae of An. sinensis breed in wide range of habitats which are naturally-made clean water, stagnant or flowing; main habitats include rice fields, ditches, streams, irrigation cannals, marshes, ponds, ground pools, etc. Their host preferences are highly zoophilic. Human blood rate is very low ($0.7-1.7\%$); nevertheless An. sinensis readily feeds on man when domestic animals are not found near by. They feed on hosts throughout the night from dusk to dawn with a peak period of 02:00-04:00 hours; they are slightly more exophagic (biting outdoors); much larger numbers come into the room when light is on. Main resting places are outdoors such as grasses, vegetable fields and rice fields. A mark-release-recapture study resulted that $37.1\%$ was recaptured within 1 km, $29.4\%$ at 1-3 km, $21.1\%$ at 3-6 km, $10.3\%$ at 6-9 km and $2.1\%$ at 9-12 km distance. An. sinensis hibernate outdoors (mostly under part of dense grasses) during October-March. At the end of the hibernation period (March-April) they feed on cows at daytime. Until today any single measure to effectively control An. sinensis population has not been found. Indoor residual spray with a long-lasting insecticide can not reduce vector population densities, but shorten their life spans in some degree, so contributes to malaria control.

Mosquito Larvicidal Activity of Synechocystis PCC6803 Transformed with the cry11Aa gene to Culex tritaeniorhynchus and Anopheles sinensis (Cry11Aa 유전자로 형질전환된 Synechocystis PCC6803의 작은빨간집모기와 중국얼룩날개모기 유충에 대한 살충효과)

  • 이대원
    • Korean journal of applied entomology
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    • v.43 no.1
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    • pp.35-41
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    • 2004
  • Bacillus thuringiensis produces crystal proteins toxic to medically and agriculturally important pests during sporulation. To improve the activity of insecticidal crystal protein in applying to mosquito larval control, an expression vector, pSyn4D harboring the mosquitocidal cry11Aa gene under control of psbA promoter of Amaranthus hybridus was constructed. This expression vector was transformed into Synechocystis PCC6803 and a transformant, Tr2C was selected with kanamycin. The mosquitocidal cry11Aa gene was stably integrated Into genomic DNA of Tr2C in PCR detection using cry11Aa-specific primers. The transformant expressed 72-kDa Cry11Aa protein and median lethal time (LT$\sub$50/) was approximately 2.1 days for Culex tritaeniorhynchus larvae and 0.7 day for Anopheles sinensis larvae, respectively. These results suggest this transformant can be used for mosquito larval control as a biological control agent.

The Mosquito Repellent Citronellal Directly Potentiates Drosophila TRPA1, Facilitating Feeding Suppression

  • Du, Eun Jo;Ahn, Tae Jung;Choi, Min Sung;Kwon, Ilmin;Kim, Hyung-Wook;Kwon, Jae Young;Kang, KyeongJin
    • Molecules and Cells
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    • v.38 no.10
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    • pp.911-917
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    • 2015
  • Citronellal, a well-known plant-derived mosquito repellent, was previously reported to repel Drosophila melanogaster via olfactory pathways involving but not directly activating Transient Receptor Potential Ankyrin 1 (TRPA1). Here, we show that citronellal is a direct agonist for Drosophila and human TRPA1s (dTRPA1 and hTRPA1) as well as Anopheles gambiae TRPA1 (agTRPA1). Citronellal-induced activity is isoform-dependent for Drosophila and Anopheles gambiae TRPA1s. The recently identified dTRPA1(A) and ag-TRPA1(A) isoforms showed citronellal-provoked currents with EC50s of $1.0{\pm}0.2$ and $0.1{\pm}0.03mM$, respectively, in Xenopus oocytes, while the sensitivities of TRPA1(B)s were much inferior to those of TRPA1(A)s. Citronellal dramatically enhanced the feeding-inhibitory effect of the TRPA1 agonist N-methylmaleimide (NMM) in Drosophila at an NMM concentration that barely repels flies. Thus, citronellal can promote feeding deterrence of fruit flies through direct action on gustatory dTRPA1, revealing the first isoform-specific function for TRPA1(A).