1. Prevent Disease, Disability and Premature Death

2. Relate the biology of ticks to appropriate control measures. Objective هدف

3. Prevent Disease, Disability and Premature Death Characteristics Life Cycle Habits Disease Agent Transmission Surveillance and Control Measures Overview مرور

4. Prevent Disease, Disability and Premature Death Ticks are arachnids: cousins of spiders and scorpions Represent a very important group of vectors of arthropod-borne diseases. These diseases include: Rickettsiae: Boutonneuse Fever, Q-Fever, etc. Spirochetes: Relapsing fever, etc. Other bacteria: tularemia, mycobacterium, etc. Viruses: Crimean-Congo HF Protozoa: Babesia, Theileria, trypanosomes, etc.

5. Prevent Disease, Disability and Premature Death Disease Agents Transmitted By Ticks Worldwide, they rank number two behind mosquitoes as vectors of disease. All life stages are obligate blood feeders Hosts can come from virtually any vertebrate group including mammals, reptiles, birds, and amphibians. Ticks are divided into two distinct families—hard ticks (Ixodidae) and soft ticks (Argasidae).

6. Prevent Disease, Disability and Premature Death GENERAL TICK MORPHOLOGY AND BIOLOGY Hard ticks & soft ticks are very different in appearance, biology, and behavior biology, and behavior. Illustration available on-line at www.howstuffworks.com

7. Prevent Disease, Disability and Premature Death Which is which? Mouthparts NOT visible from above Mouthparts visible from above Soft TickHard Tick

8. Prevent Disease, Disability and Premature Death Hard Ticks (Family Ixodidae) Have a stiff, leathery cuticle on their back called a scutum Covers entire back of the male A small plate on back of female Mouthparts project off the front of the tick and are visible from above Males are smaller than females

9. Prevent Disease, Disability and Premature Death HARD TICKS (FAMILY IXODIDAE) Sexual Dimorphism: males are smaller than females Sexual Dimorphism: males are smaller than females Left to Right: Attached male, attached gravid female, attached gravid & engorged female Sexual dimorphism is the systematic difference in form between individuals of different sex within the same species.

10. Prevent Disease, Disability and Premature Death Life cycle of hard ticks EggEgg Larva -- 6 legsLarva -- 6 legs Nymph -- 8 legs, but sexually immatureNymph -- 8 legs, but sexually immature Adult -- 8 legs, sexually matureAdult -- 8 legs, sexually mature Molt (shed skin) only once between each successive life stageMolt (shed skin) only once between each successive life stage

11. Prevent Disease, Disability and Premature Death Life cycle of hard ticks Female lays thousands of eggs at one timeFemale lays thousands of eggs at one time

12. Prevent Disease, Disability and Premature Death Life cycle of hard ticks Larval ticks emerge seemingly all at once and only have six legs during this stage

13. Prevent Disease, Disability and Premature Death Life cycle of hard ticks After molting and developing their last pair of legs, nymphal ticks seek a blood meal from smaller animals.

14. Prevent Disease, Disability and Premature Death Life cycle of hard ticks Nymphal ticks molt into adults, and seek out larger animals for a blood meal.Nymphal ticks molt into adults, and seek out larger animals for a blood meal. Adults attach tightly to host and feed over a period of hours, days, or weeks.Adults attach tightly to host and feed over a period of hours, days, or weeks.

15. Prevent Disease, Disability and Premature Death Life cycle of hard ticks Adults mate on the host, usually reproduce only once.Adults mate on the host, usually reproduce only once. Adult female falls to the ground, lays eggs, and dies shortly thereafter.Adult female falls to the ground, lays eggs, and dies shortly thereafter.

16. Prevent Disease, Disability and Premature Death Soft Ticks (Family Argasidae) Males and females are very similar in appearance Lacks a scutum Body ranges from fleshy to leathery in texture Mouthparts are located underneath the body towards the front, and are not visible from above

17. Prevent Disease, Disability and Premature Death Soft Ticks (Family Argasidae) Ventral side of a soft tick. Note that the mouthparts are tucked underneath

18. Prevent Disease, Disability and Premature Death Egg -- Very hardy Larva -- 6 legs Nymph -- 8 legs, but sexually immature Molt 5-7 times during nymphal life stage Adult -- 8 legs, sexually mature LIFE CYCLE OF SOFT TICKS

19. Prevent Disease, Disability and Premature Death Mate off the host, reproduce several times. Attach to host only to feed Loosely attach & feed rapidly Hide in cracks & crevices of host’s nest, bedding, or home LIFE CYCLE OF SOFT TICKS

20. Prevent Disease, Disability and Premature Death High vector potential Great Reproductive Capability Can lay a tremendous number of eggs Production of several thousand eggs isn’t uncommon Persistent Bloodfeeders If they’re not feeding on a host, they’re looking for one Ticks climb vegetation and “grabs” the host as it passes. This is known as “questing.”

21. Prevent Disease, Disability and Premature Death High vector potential Relative Freedom from Natural Enemies There’s not too many things that eat ticks Fire ants seem to like them fine Encyrtid Wasp only known parasitoid Photo by: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

22. Prevent Disease, Disability and Premature Death High vector potential Slow Feeding Hard ticks take up to 2 hours to find an attachment point. Usually requires 4 - 24 hours of feeding before the pathogens leave the tick and enter host A hard tick may take 5 - 7 days to feed

23. Prevent Disease, Disability and Premature Death Wide Host Range 1-, 2-, or 3- host ectoparasites. Risk of disease transmission greatly increases with multiple host ticks E.g., the black-legged tick feeds on mice as a larva, larger animals like raccoon as a nymph, and deer as an adult. HIGH VECTOR POTENTIAL

24. Prevent Disease, Disability and Premature Death Longevity Hard ticks may live 3 - 5 years Soft ticks may live 15 - 20 years Transovarial Transmission Of Pathogens Pathogen is passed from the female tick to the embryonic egg When the eggs hatch, the larvae emerge already infected with the pathogen Ticks are thus reservoirs for diseases HIGH VECTOR POTENTIAL (HARD TICKS)

25. Prevent Disease, Disability and Premature Death Hard Ticks “Transitional Zones” Deep woods Shrubby areas Shorter grasses and weeds Vegetation along animal trails On the host Soft Ticks Cracks and crevices of host’s burrow Abandoned dwellings and caves infested by animal hosts TICK HABITAT

26. Prevent Disease, Disability and Premature Death Drag Cloth Method TICK SURVEILLANCE Flannel Sheet & Dry Ice

27. Prevent Disease, Disability and Premature Death Vegetation Reduction Cut-back or totally remove habitats Host Exclusion Construct physical barriers to keep tick-infested hosts out of areas where personnel will inhabit. TICK CONTROL

28. Prevent Disease, Disability and Premature Death Pesticides General area application for hard ticks is impractical since they spend most of time on host Treatment is only temporary May serve well as a barrier treatment around tents or areas requiring protection against ticks TICK CONTROL

29. Prevent Disease, Disability and Premature Death Personal Protection from Ticks Avoidance Refrain from entering areas that are known to be infested with ticks. Reduce activities in those areas when complete avoidance is impractical.

30. Prevent Disease, Disability and Premature Death Proper Wear of Clothing This includes wearing clothing that will prevent ticks from reaching your skin, such as long sleeves and long pants. Tuck your shirt into your pants and your pant cuffs into your socks or boots. Personal Protection From Ticks

31. Prevent Disease, Disability and Premature Death Personal Protection from Ticks Tape Barriers Wrap double-sided tape or regular tape with the adhesive side out to form a sticky barrier which will form an external barrier on your uniform. Ticks are “unidirectional” (travel in one way—upward) and will get stuck as they climb up your pants.

32. Prevent Disease, Disability and Premature Death Repellents (covered in detail in PPE lecture) Permethrin (Aerosol or IDA kit) treatment of uniform. DEET lotion for skin. Personal Protection from Ticks

33. Prevent Disease, Disability and Premature Death Tick removal Search for and remove ticks as soon as possible The longer the tick remains attached, the more engorged and difficult it becomes to remove The longer the tick remains attached, the more likely the chance of infection, disease transmission, or tick paralysis

34. Prevent Disease, Disability and Premature Death Tick removal DON’T “bare hand” ticks Ticks may shed pathogens in their feces at any time, and these may contaminate cuts or abraded skin Fingers contaminated with infected feces may introduce pathogens (especially viruses & rickettsias) through the mucus membrane of the nose or eyes

35. Prevent Disease, Disability and Premature Death Tick removal DON’T use Vaseline WON’T WORK!!! Ticks cannot be suffocated (Acquires oxygen needs from your blood) Tick leaves only when it has finished feeding The longer it remains attached, the greater chance for disease transmission

36. Prevent Disease, Disability and Premature Death Tick removal DON’T use Fingernail Polish WON’T WORK!!! Ticks cannot be suffocated (acquires oxygen needs from your blood) Tick leaves only when it has finished feeding Solvent in fingernail polish may irritate tick Irritated tick may regurgitate gut contents and pathogens into your blood…increasing chance of infection

37. Prevent Disease, Disability and Premature Death Tick removal DON’T use Matches/Fire WON’T WORK!!! Tick might be killed and will never leave At the very least, tick will be irritated Irritated tick may regurgitate gut contents and pathogens into your blood…increasing chance of infection Potential damage to skin may enhance pathogen transfer into body

38. Prevent Disease, Disability and Premature Death Tick removal DON’T use Gadgets/Pliers Usually Don’t Work!!! Tick will be crushed or at least squished Squished tick will have gut contents and pathogens squished into your blood May cut the tick from its mouthparts, leaving the mouthparts in the wound and causing possible infection

39. Prevent Disease, Disability and Premature Death Tick removal USE Fine-Pointed Forceps Grasp tick by mouthparts as close to skin as possible (Figure 1) Using slow & steady pressure, gradually pull tick from skin (Figure 2). Skin may stretch a bit, but that is okay.

40. Prevent Disease, Disability and Premature Death Tick removal USE Fine-Pointed Forceps After tick detaches, check the mouthparts (Figure 3) If clump of your skin attached, you got the whole tick If no clump of skin attached, mouthparts broke off in skin Secondary infection possible if mouthparts not removed

41. Prevent Disease, Disability and Premature Death Summary Characteristics Life Cycle Habits Disease Agent Transmission Surveillance and Control Measures

42. Prevent Disease, Disability and Premature Death Questions?سوالات