1 / 24

Parasitic arthropods cont’d.

1-5mm. Parasitic arthropods cont’d. Jo Hamilton Parasitology BS31820. 6-14mm. 5-7mm. (c). Flies - as vectors. Family Psychodidae – sandflies. Vectors of Leishmania - protozoa. Cutaneous leishmaniasis: L. tropica - Old World. L. mexicana - New World.

liam
Download Presentation

Parasitic arthropods cont’d.

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. 1-5mm Parasitic arthropodscont’d. Jo Hamilton Parasitology BS31820 6-14mm 5-7mm

  2. (c). Flies - as vectors. • Family Psychodidae – sandflies. • Vectors of Leishmania - protozoa. • Cutaneous leishmaniasis: • L. tropica - Old World. • L. mexicana - New World. • Mucocutaneous leishmaniasis (espundia) - L. braziliensis. • Visceral leishmanisis(kala azar) - L. donovani.

  3. (c). Flies - as vectors Family Simuliidae - Blackflies. • Simulium damnosum - vector in Africa. • Simulium ochraceum - vector in New World. • Vector Onchocercavolvulus(‘river blindness’). • In Australia Simulium spp.infect cattle O. gibsoni – economic loss.

  4. (c). Flies as vectors Family Glossinidae, genus Glossina – tsetse flies. • Hosts & vectors of trypanosome protozoans. • Trypanosomabrucei species complex. • Sub-saharan Africa.

  5. (d). Hemipterans. Up to 2.5cm Class Insecta. Order Hemiptera. • Parasitism in 2 lineages. • Mouthparts - piercing/sucking. 1. Family Reduviidae. Subfamily Triatominae. 2. Family Cimicidae - bedbugs.

  6. Economic impact of vector-borne diseases. • Morbidity & mortality. • Human health & productivity. • Losses to draught & pack animals. • Milk & meat yields. • Damage to skins & hides & wool quality. • Losses in agriculture, companion animals & sport animals. • Fertiliser?

  7. 2-8mm Advances in the control of Ctenocephalides felis (cat flea) on cats and dogs. Michael K. Rust. Trends in Parasitology21:232-236.

  8. 2-8mm Introduction • Cat flea • Important ectoparasite - cats & dogs. • Topical & oral insecticides revolutionised control. • Eliminate need to treat environment. • Reduces flea allergic dermatitis (FAD). • Insecticidal resistance? • Extend longevity of these new compounds.

  9. Flea control on cats & dogs • Cat flea, Ctenocephalides felis. • Most problematic. • Discomfort • Pets & owners (parasite psychosis) • Vectors • tapeworm • Cause flea allergic dermatitis (FAD). • Role in feline leukaemia & cat scratch fever? • Annual control expenditures • >US$1bn – USA. 1.1billion euro in Western Europe.

  10. 2-8mm Flea control on cats & dogs • Revolutionary control products in past 10 years • systemic & topical • Eliminates need to treat environment • Only need to treat animal. • Determining efficacy of treatment in field difficult. • Comb - 5 mins – estimate flea population. • Flea distribution - head & neck.

  11. 2-8mm Questions?

  12. 2-8mm Flea biology • Where do flea infestations originate? • How do animals that live indoors get infected? • Reinfestation after successful treatment? • Feral animals reservoirs? • Lack of evidence. • Feral animals infected by fleas from companion animals. • Overlapping territories – transfer cycle. • Preventative use control products for pets exposed to outdoors.

  13. Flea biology • Immature fleas: • Require RH >50%. • Temp 4 -35OC. • Feed on dried blood & yeast • Adult flea faecal blood • Cannibalism of non-fertile eggs • Adult male & female BSIs • Mating • On host • Male - fully fed 11min • Female – fully fed 25 min

  14. Questions?

  15. Host-targeted therapy • Oral / topical treatments. • 1995 – registration of lufeneron. • Avermectins • Fipronil • Imidacloprid • Nitenpyram • Pyrethroids & pyrethrins • Insect growth regulators • Juvenile-hormone analogues (JHAs) • Insect developmental-inhibitors (IDIs)

  16. Questions?

  17. Flea allergic dermatitis (FAD) studies. • Caused by hypersensitivity to flea saliva components • Individuals – varying severity. • New concept – oral & topicals can manage FAD. • If treatment prevents feeding – no allergen. • Continuous or episodic feeding = FAD. • Examples of compounds that inhibit feeding.

  18. Questions?

  19. Insecticide resistance. • Pest status cat flea • Extend longevity of current treatments. • Monitoring programmes - insecticidal resistance. • Need bioassays – adults – larvae. • Background levels – resistance & susceptibility. • No universally susceptible strains • Use lab strains for baseline • Maintenance & distribution of lab strains for research

  20. Insecticide resistance. • Cat fleas tend to develop resistance. • Limited reports of resistance to new compounds • “Cottontail” strain • Field–collected strain

  21. Insecticide resistance. • Rdl gene mutations– associated with resistance • Cyclodienes • Fipronil • PCR-based diagnostics • Resistance in a UK field population • Promising technique for monitoring potential resistance.

  22. Questions?

  23. Concluding remarks. • Challenge: • develop control strategies that conserve these therapies. • Monitoring • Knowledge application • Stewardship • Vets & pet owners

  24. Questions?

More Related