1 / 27

LECTURE PROPER

LECTURE PROPER. VECTOR. An arthropod (insects, mites, ticks) that are capable of: acquiring, supporting the development and transmitting a pathogenic agent (bacteria, viruses, parasites) from one host to another host. Ex: mosquito Aedes aegypti transmitting dengue virus. VECTOR CONTROL.

stanislaw
Download Presentation

LECTURE PROPER

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LECTURE PROPER

  2. VECTOR • An arthropod (insects, mites, ticks) that are capable of: acquiring, supporting the development and transmitting a pathogenic agent (bacteria, viruses, parasites) from one host to another host. Ex: mosquito Aedes aegypti transmitting dengue virus

  3. VECTOR CONTROL • suppression of a target population by using measures to alter the vector reproductive capacity or potential (Vector Genetics Course, 2010, India). NET REPRODUCTIVE RATE (NRR) and GROSS REPRODUCTIVE RATE (GRR)

  4. NET REPRODUCTIVE RATE (NRR) • refers to the survival of eggs of mosquitoes to adults (number of eggs surviving to become adults) • dependent on the following: 1. number of containers available for Aedes vectors to lay their eggs

  5. NET REPRODUCTIVE RATE (NRR) • dependent on the following: 2. condition of the containers; can hold water for at least seven (7) days; covered; uncovered 3. interspecies competition Ae. aegypti vs Ae. Albopictus

  6. NET REPRODUCTIVE RATE (NRR) • dependent on the following: 4. Predators 5. Larvicides 6. Larval food; temperature for pupal development

  7. NET REPRODUCTIVE RATE (NRR) EX: 100 eggs laid on the trap/any container How many will emerge as adults? 0; 25; 50; 100?

  8. GROSS REPRODUCTIVE RATE (GRR) • refers to the number of adult females surviving through one day to lay their eggs • influenced by: 1. female adult completion of gonotrophic cycle 2 to 3 days (> 250C); obtaining their blood meal and laying their first batch of eggs

  9. GROSS REPRODUCTIVE RATE (GRR) • influenced by: (early death within a day; prevents an adult female to mate with adult males) • no mating; no blood meal; no laying of eggs • this is where adulticides are useful

  10. GROSS REPRODUCTIVE RATE (GRR) EX: 100 eggs laid on the trap/any container 50 emerged as adults 25 died on day 1 25 survived and successfully mated 20 died on day 2 only 5 survived on day 3 and fed on humans

  11. DENGUE VECTOR CONTROL Application of various anti-DEN mosquito measures to alter the NRR and GRR

  12. DENGUE VECTOR CONTROL • Specific targets: • Prevent DEN transmission and cut DEN transmission through: 1. lowering the NRR by - trapping(ovitrapping/ OLtrapping ) - larviciding - container management - environmental sanitation

  13. DENGUE VECTOR CONTROL • Specific targets: through: 2. lowering the GRR by: - adulticiding (space-spraying; aerosol treatment) - genetic manipulation of the reproductive capacity of the mosquito

  14. DENGUE VECTOR CONTROL • Specific targets: through: 3. prevention and man-mosquito contact - curtains - long trousers - repellents

  15. INTEGRATED (DEN) VECTOR CONTROL integration/combination of measures to reduce the NRR and GRR

  16. INTEGRATED (DEN) VECTOR MANAGEMENT • utilization of technical and managerial measures to bring about an effective degree of vector suppression to prevent and control DEN transmission Key words: effective degree of vector suppression

  17. COMPONENTS OF IVC • Vector biology/behavior – Aedes DEN vectors • Surveillance tool; ovitrap/oltrap Surveillance index 3. Critical Threshold Density Index(ces) or effective degree of vector suppression (OL Index) 4. Control measures 5. Monitoring and Evaluation

  18. The Vector

  19. WHAT : (Mosquito and Dengue) Biology 1.1 Aedes mosquito vectors a. Aedes aegypti b. Aedes albopictus

  20. Vector Characteristics • Biting Habits • “daybiters” with two peaks of biting time: • 1 to 2 hours after sunrise • 1 to 2 hours before sunset • only female mosquitoes bite because of the requirement of blood for oviposition • males do not bite but feed on plant juices and nectar of flowers

  21. Vector Characteristics • Flying Habit • do not fly great distances • farthest flight distance is within 200 to 400 meters radius from their breeding places • Adults found around 50 meters from the breeding sources

  22. Bionomics • at temperatures <10oC and >40oC, no developmental process takes place • female mates with male only once • oviposition takes place about 2 to 5 days from blood engorgement • prefers dark-colored background for oviposition • lays egg 3 to 4 times in its lifetime • 60 to 100 eggs per batch

  23. Life Cycle (10-12 days) Adult -Wings uniformly grayish black -Body and legs are black with distinctive white patches throughout -Thorax has markings Eggs: - Black and oval in shape - Laid singly above water surfaces of containers 2 - 3 days 1 - 2 days Larva: - Feeding stage - Breeds in clean and non-polluted water - Rests at an angle to the water surface Pupa -Non-feeding stage -Breeding trumpet is long, slender with narrow opening 6 - 8 days

More Related