TICKS & MITES2.pptx power point presentation

entomology

1. TICKS & MITES 3/1/2018 1 Presenter –Dr Elizabeth

2. Introduction Ticks and mites compromise one of the largest and most important arthropod Phylum – Arthropod Class - Arachnida Order – Acarina They are ectoparasites of verteberate animals They all suck blood 3/1/2018 2

3. TICKS 3/1/2018 3

4. Taxonomy Ticks belong to the super-family Ixodoidea Family Ixodidae - Hard tick Family Argasidae - Soft tick Hard tick is more a jungle tick Soft tick is a domestic or household tick like a bedbug. 3/1/2018 4

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6. Morphology Large size and absence of prominent hairs on the body Oval in shape and dorsoventrally compressed No distinction into head, thorax & abdomen 4 pairs of legs & no antennae Females are larger than males 3/1/2018 6

7. Morphology – Hard ticks Dorsum of the adult male is covered by a dark shield called the scutum This may be with grey or white ‘patterns’ 3/1/2018 7

8. Morphology – Hard ticks 3/1/2018 8 Scutum 4 pairs of legs

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10. Morphology – Soft ticks These are oval with leathery cuticle Devoid of scutum Their mouth parts are placed ventrally and hence not visible from above No festoons 3/1/2018 10

11. Soft ticks 3/1/2018 11

12. Life history 3/1/2018 12

13. Life cycle 3/1/2018 13 EGG Hard ticks lay eggs in a few hundreds or even thousands Soft ticks lay eggs in batches of 20 to 100 over a long period Eggs are deposited on the ground and hatch in 1 to 3 weeks Female is exhausted and dies

14. Larva 3/1/2018 14 The larva of the tick possesses 3 pairs of legs Lies among grass and herbiage till a suitable host appears to which it attaches itself After a blood meal, it drops off, it moults to become a nymph Duration of the larval stage may vary from 3 to 13 days

15. Life history 3/1/2018 15 NYMPH Resembles the adult in having 4 pairs of legs Has no genital pore The nymphs are all blood suckers 5 nymphal stages in the life history of soft ticks

16. Life history 3/1/2018 16 ADULT Duration of the life cycle from egg to adult is about 2 months in the case of hard ticks 9 to 10 months in the case of soft ticks Adult ticks may live for a year or more Soft ticks live longer than hard ticks

17. Bionomics Hard ticks feed both night and day and cannot stand starvation Soft ticks, feed at night and can withstand starvation for several months Hard ticks are always found on their hosts Soft ticks hide in cracks and crevices during the day and emerge at night to feed on the host 3/1/2018 17

18. Transmission Ticks transmit disease by biting The larva and nymph are also capable of transmitting disease by biting (i.e., infection is maintained trans- stadially ) Transovarian transmission of infection through successive generations Helps in maintaining infection for several years 3/1/2018 18

19. Public health importance 3/1/2018 19 Hard ticks transmit the following diseases Viral fevers (e.g., Colorado tick fever) Viral haemorrhagic fevers (e.g. KFD in India) Viral encephalitis (e.g., Russian spring-summer encephalitis) Tick typhus (Rocky mountain spotted fever) Tularaemia Tick paralysis Human babesiosis Lymes disease

20. Public health importance 3/1/2018 20 Soft ticks transmit Q fever Relapsing fever Kaysanur Forest Disease( KFD)

21. Comparison of hard & soft ticks HARD TICK ( Ixodidae ) SOFT TICK ( Argasidae ) Scutum Covers the entire back in males; only a small portion in front in females Absent Head Situated at anterior end Lies ventrally; not seen from above Spiracles Situated behind IV coxa Situated between III & IV coxa Eggs Several hundreds or thousands laid at one sitting Laid in batches of 20 – 100 over a long period Nymphal stages One Five 3/1/2018 21

22. Comparison of hard & soft ticks HARD TICK ( Ixodidae ) SOFT TICK ( Argasidae ) Habits Cannot stand starvation; feed night and day Can stand starvation for a year or more Diseases transmitted Tick typhus transmitted Viral encephalitis Haemorrhagic fever Tularaemia Tick paralysis Human babesiosis Relapsing fever Q fever KFD Important species Dermacentor andersoni Haemophysalis spinigera Ornithodorus moubata O crossi 3/1/2018 22

23. MITES 3/1/2018 23

24. Introduction Mites - 4 pairs of legs - body not well demarcated into head,thorax and abdomen From the public health standpoint, two mites are important Trombiculid mite (chiggers) Itch mite ( Sarcoptes scabiei ) 3/1/2018 24

25. Mites of public health importance 3/1/2018 25 Itch mite ( Sarcoptes scabiei ) Itch mite ( Sarcoptes scabiei ) Trombiculid mite (chiggers)

26. Trombiculid Mites Spider like arthropods Important species Trombicula deliense T . akamushi Vectors of scrub typhus in Asia & South Pacific 3/1/2018 26

27. Life cycle of Trombiculid mite (chiggers) 3/1/2018 27

28. Life history Four stages Egg – laid singly - hatch in about a week Larva – small - pale orange in color - 3 pairs of legs 3/1/2018 28

29. Life history Nymph - brick-red colour and has 4 pairs of legs - lives on vegetable juices - lasts for 1 to 3 weeks Adult - The adult male lives in soil - 4 pairs of legs, the first pair being the largest - Lives for about 6 months 3/1/2018 29

30. Adult and larva forms of Trombiculid mite 3/1/2018 30

31. Diseases transmitted Tsutsugamushi disease – Trombiculia akamushi Mite borne typhus fevers like scrub typhus – T akamushi & T.deliensis 3/1/2018 31

32. ITCH MITE ( Sarcoptes scabiei ) 3/1/2018 32 Discovery in 1687 Extremely small, globular Female parasite burrows into epidermis Infest animals like dogs, cattle & horse Itch mite is not a vector it directly causes harm and gives rise to itch

33. Morphology 3/1/2018 33

34. Life history EGG The female burrows within the stratum corneum & lays eggs in the burrow A single female may lay up to 30 eggs at the rate of 2 to 3 per day Dies at the end of the burrow The eggs hatch into larvae in 3 to 4 days 3/1/2018 34

35. Life history Larva Three legged They leave the burrows, come to the surface and bore into the hair follicles where vesicles form The larvae mature into nymphs in about 3 day 3/1/2018 35

36. Life history Nymph Develop into adults in 6-8 days Adult Life cycle from egg to adult take 10-15 days Adult mites live for 1 to 2 months 3/1/2018 36

37. Mode of spread Close contact Contaminated clothes, bedding, bedsheets etc 3/1/2018 37

38. Lesions 3/1/2018 38 The axillae, buttocks, lower abdomen, feet and ankles, palms in infants are all common sites of infestation

39. 3/1/2018 39 Classically affects the hands and wrist (63%) Extensor aspect of elbows being next (10.9%)

40. Lesions The disease also affects the breasts in women and the genitals in men 3/1/2018 40

41. Lesions- Burrows 3/1/2018 41

42. Control of scabies Benzyl Benzoate (25%) – an effective sarcopticide Lindane – 0.5 to 1.0% gamma HCH Tetmosol ( 5%) Sulphur ointment ( 2.5 to 10% ) 3/1/2018 42

43. Control of ticks & mites Insecticidal control DDT, chlordane, lindane , malathion 1 to 2 lbs per acre give effective control Area treatment On vegetation Premises – malathion or propoxur spray Domestic animals – wash or spray containing 2% malathion, 1% propoxur 3/1/2018 43

44. Control of ticks & mites Environmental control Cracks & crevices in ground to be filled up Animal hosts should be reduced (Anti rodent measures) Protection of workers Protective clothing impregnated with insect repellent Indalone , diethyltoluamide and benzyl benzoate Tick picking Blanket therapy for mites – treatment for family members & contacts 3/1/2018 44

45. MCQ’s 1.Diseases spread by ticks.(PGI 2013) Epidemic typhus Endemic typhus Scrub typhus Rocky mountain spotted fever Crimean congo fever 3/1/2018 45

46. MCQ’s 2.KFD is transmitted by Tick Mite Sand flea Mosquito 3/1/2018 46

47. MCQ’s 3.Which of the following viral diseases is transmitted by tick ? Japanese encephalitis Dengue fever Kyasanur forest disease Yellow fever 3/1/2018 47

48. MCQ’s 4.Soft tick transmits all of the following except Q fever Relapsing fever KFD Rocky mountain spotted fever 3/1/2018 48

49. MCQ’s 5.Average number of mites found on the body in a person suffering from scabies is (DNB) 1-2 5-10 10-15 15-20 3/1/2018 49

50. 3/1/2018 50 Hard tick Soft tick Dorsum Ventral

51. 3/1/2018 51 Head 1 st and 2 nd pair of legs with suckers 3 rd and 4 th Pair of legs with bristles Sarcoptes scabiei

52. THANK YOU 3/1/2018 52