kul arachnida

7/28/2019 Kul Arachnida

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kuliah S-1 FK dr Teguh WSJun-13

Phylum: Chelicerata(Arthropoda)Class: Arachnida

Dr. Teguh Wahju Sardjono, DTM&H, MSc.Laboratorium Parasitologi

Fakultas Kedokteran Unibraw


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kuliah S-1 FK dr Teguh WSJun-13

Phylum: Chelicerata

(Arthropoda)Class: Arachnida

There are 7 orders, three orders are MedicallyImportant :

Acarina (Ticks and Mites)

Scorpionida (Scorpion)Araneae /Araneida (Spiders)


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Jun-13 kuliah S-1 FK dr Teguh WS

General morphological characteristics :

Cephalo thorax No antenna With or without eyes Hypostome Chelicera Pedipalp

4 pairs of legs Wingless Genital opening - ventral


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Life cycle

Oviparous hemimetabolous Ova hatches to be larvae (6 legs) Nymphs adults (8 legs) but no genital organ The nymphs molt 8 legged male or female

adult ticks climb up grass and plants andhold their legs up "sensing" and "looking" fortheir prey

Male and female ticks usually mate while

attached to the host. A few weeks later, theengorged female detaches from the host andlays her eggs (1000 - 8000 eggs) on a leaf.

A tick usually lives a year before dying.


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Order : Acarina

Family Ixodidae = Hard ticks Family Argasidae = Soft ticks

Family Trombiculidae = Chiggers Family Sarcoptidae Family Demodicidae

Family Tyroglyphidae


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Morphological Characteristics

Adult form four pairs of legs Cephalothorax, no segmentation

Mouthparts prominent capitulum Nymphs four pairs of legs, no genital organ Larva form three pairs of legs

Scutum : dorsal of the body, covers a half orwhole of dorsal body


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Order : AcarinaFamily :Ixodidae

(Hard ticks) Round or oval. 1 mm- 1 cm. female > male

Jointed Cephalothorax and Abdomen Capitulum (false head) visible from dorsal Mouth parts :

A pair pedipalp 4 segments.

A pair chelicera (cutter)

Hypostome; at ventral some rows of teeth


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4 pairs of legs (adult and nymph) : coxa, trochanter, femur, genu, tibia and tarsus

3 pairs of legs (larva)

spiracle (stigmata) breathing organ: behind coxa IV Scutum :

Male : fully covering dorsal part of the body

Female : half/anterior-dorsal part.


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From the left, larva, nymph,two engorged nymphs,female (top), and male(bottom).

Ticks begin as eggs (stage 1)hatch into 6-legged larvae(stage 2).

Larvae live and feed on animalsfor about a week beforedetaching then molting(shedding) anywhere from 1week to 8 months later.

The larvae then become 8-legged nymphs(stage 3).Nymphs feed on animals,engorge for 3 to 11 days, detach,and molt about a month later(on the species and

environmental conditions). Ticks insert their mouths, attachto their prey, and engorgethemselves with a blood meal(stage 4).

Life cycle


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Ovipositing (left) and unengorged (right) females ofIxodesscapularis. (Bottom scale in mm.)


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Various life cycle stages ofIxodes scapularis.Top left = male; bottom left = female; center = nymph;

right = ovipositing female. (Top scale in mm.)


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Brown dog tick (Riphicephalus)


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Classificationdepends on number of hosts required for

completing their life cycle

One host ticks:Hyalomma, Boophilus. Two host ticks: Riphicephalus. Three host ticks: Ixodidae, Dermacentor,

Haemaphysalis

Many host ticks : goes through many stages

during its lifecycle, and feeds on differentspecies at each point. Ornithodoros.


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Medical Importance

1. Tick bite :

a. Mechanical primer & secondary effectb. Tick paralysis : (neurotoxin)

- Dermacentor

- Amblyoma Amerika- Ixodes Australia, Africa

Characteristics of paralysis:

- Flaccid- Ascending

Treatment

- Remove the tick with chloroform, ether, alcohol

- Avoid contaminationwith ticks secrete


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2. Transmission of many diseasesTrans-stadial or Trans-ovarial

a. Rickettsial Diseases (Ehrlichiosis)- Rocky Mountain Spotted Fever -R. rickettsii.(trans-ovarial) Dermacentor andersoni Amblyoma americanum Riphicephalus sanguineus

- Q fever(R. burnetti ) Dermacentor andersoni Amblyoma americanum Ixodes Ornithodorus

- Boutonneuse fever(R. conorii.) Amblyoma hebraeum Rhipicephalus sanguineus

- African Tick fever(R. conorii.)


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b. Viral diseases Colorado tick fever: D. andersoni Russian spring and summer encephalitis: D. silvarum- Hemorrhagic fevers : Hyalomma marginatum Kyasanur forest disease : Haemophysalis spimigera

c. Bacterial and Spirochaetal diseases:- Lyme Disease

- Tularemia Amblyomma americanum Dermacentor andersoni Dermacentor variabilis

- Relapsing fever Ornithodorus

Controlinsecticides : DDT, Chlordane, Dieldrin


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Lyme disease a tick-borne multisystem infectious syndrome of substantial

medical importance and public concern. the most frequently reported vector-borne illness in the US

(>12,000 cases annually). also has been seen on four other continents. The causative organism: Borrelia burgdorferi:

(a flagellated spirochete) transmitted from small-mammal reservoirs to humans through bites from infected ticks of Ixodes species I. scapularisin US (deer ticks) I. pacificusin California, (deer ticks) I. ricinusin Europe, and (sheep ticks) I. persulcatusin Asia


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Lyme disease Relatively new disease (1975)Three stages: Stage 1:rash, flu like syndrome, including fatique, stiff neck,

muscle aches and pain, within 30 days post infection

Stage 2 : next several weeks inflammation of the brain,nerve roots, facial paralysis, dizziness, shortness of breath,heart beat irregular.

Disappear within several weeks.

- Stage 3 : arthritic problem may appear 2 years after the rash pain, swelling, elevated temp. in joints. Sleep walking, lossof memory, mood changes, inability to concentrate.

Treatment: Antibiotics


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Treatment

Oral therapy for early localized disease (10 to 21 days)

Doxycycline (Vibramycin)* 100 mg twice daily

Not recommendedin pregnant women. Amoxicillin 250 to 500 mg three times dailyChildren Amoxicillin 40 mg per kg per day Erythromycin 30 mg per kg per day

Phenoxymethylpenicillin 25 to 50 mg per kg per dayIntravenous therapy for disseminated and late disease Ceftriaxone (Rocephin) 2 g every day or 1 g twice daily Cefotaxime (Claforan) 3 g twice daily Penicillin G 20 U every 4 hrs

Chloramphenicol (Chloromycetin) 50 mg /kg /day in 4 divided dosesChildren Ceftriaxone 75 to 100 mg per kg per day Cefotaxime 90 to 180 mg per kg per day in divided doses Penicillin G 300,000 U per kg per day in 6 divided doses


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Order : AcarinaFamily : Argasidae

(Soft ticks) Mostly are ectoparasites of birds Tropic and sub tropic areas

Genus : Otobius : pets

Argas : birds

Ornithodoros : human


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General characteristics

Oval shape, may vary in size - depends on theamount of sucked blood

no scutum

without or with eyes, if with lateral position. Capitulum at ventral not visible from dorsal can

be used to distinguish between Argasidae andIxodidae

Spiracle at ventral of 4th coxae.

Adult form : 4 pairs of legs Male and female are difficult to be distinguished


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Life cycle

Hemimetabolous Life longer months - year

Female may lay 10 1000 eggs after blood meal several times (Remember: Female Ixodids

dye after oviposition)

Has 4 - 5 stages of nymphs needs bloodmeal for each moulting


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Medical importance

Biting Tick borne relapsing fever

Treponema dultoni

O d i


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Order : AcarinaFamily : Trombiculidae

(Red bugs = Chiggers, Harvest mites, Scrub itch mites)

Hundreds species, distributed in all parts of the world Hemimetabolous : (egg, larva, nymph, adult) Only larva stage is parasitic Yellow colour or orange

Six hairy legs

0,15 - 0,3 mm Dorsal part : scutum (+) Mouth parts, celicera and palps jointed together forming

pseudo head Needs blood of mammals, birds or reptils

Trombiculidae :Trombicula akamushi Adult stage : free living, hairy 1- 1.5 mm, Eight legs


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Habitats:Areas that contain thick layers of pine straw or leaf litter

Medical importances chiggers do not burrow into the skin. feed at the base of a hair follicle or in a pore. generally attach to those areas of the body where clothing fits

tightly, such as at the sock line and waistline.

Larvae ingest lymph and partially digested cells after the chiggerattaches commonly cause itching 3 to 6 hours, dermatitisdevelops 10 to 16 hours.

allergic reactions to the bites blister-like lesions. Chiggers do not transmit any disease agents to people. The adults

and nymphs are free-living predators of insects.
http://www.ces.ncsu.edu/depts/ent/notes/Urban/mites.htmhttp://www.ces.ncsu.edu/depts/ent/notes/Urban/mites.htm


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Medical importances

Biting dermatitis Scrub itch

Autumnal itch

Treatment :

Topical : sulfur ointment

vector of ScrubTyphus

(Ricketsia tsutsugamushi) Trombicula akamushi

Trombicula deliensis

Mite bite site


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Control : Treating chigger-infested areas with a pesticide spray.

Ground cover in these areas should be wetted down to the soilsurface.

Avoid excess treatments that can lead to pesticide runoff intocreeks, streams and storm sewers

Personal protection Insect repellents.

DEET or Permanone (permethrin) clothing.

DEET is appropriate to use on exposed skin. Repellents should be used in moderation by children and

pregnant women.


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round, transluscent, dirty white

six legged larvae

eight short legged nymphs and adults

male 0.2 mm1st , 2nd , 4th legssucker ended 3rd leg bristle endedfemale 0.3-0.4 mm:

1st and 2nd legs sucker ended, 3rd and 4th legs bristle ended

Order : AcarinaFamily : Sarcoptidae

Species : Sarcoptes scabiei


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the period from eggs to mature adults takes 1014 days

both male and female make short burrows inhorny superficial layer of the skin.

The gravid female lays her eggs in a burrow. The larvae hatch out after 3-4 days, leave the

burrow for the skin surface and shelter in the hairfollicles.

After 4-5 days the adults mate and the femaleburrows into the skin to complete the cycle.

The adult live for 4-5 weeks. Itch mites are active mainly overnight.

Life cycle


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Prefered sites:

axilla, around the waist, inner aspect of thighs, back of the legs,

interdigital and popliteal folds and also all over the body

Clinical features: The activities and secretions cause intense itching of affecting area.

Small vesicles and rash may be seen on the skin surface. Scratching may convert the papule into pustule (bleeding,

secondary bacterial infection)Norwegian Scabies

Complication In immunosupressed persons crusted scabies secondary infection with -haemolytic streptococci

glomerulonephritis


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Distribution:

world wide usually associated with: unhygienic life-style,

poor hygienic inadequate water supply

wide spread in the tropics, especially children

Transmission direct skin contact sexually transmitted

Through bedding and clothing

TreatmentLocal :

Benzyl Benzoate Emulsion 20 -25%

Crotamiton Benzene Hexachloride (Lindane) Sulfur soap


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Controls

Recognize symptoms Inspect all contact individuals Treat all infested persons Isolate infested person for 24 hours after treatment has

been applied

Machine wash bed linens, clothing and all other possiblecontaminated articles in hot (130F) water

Soap or thightly sealing non-washables in plastic bags fortwo weeks


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Other mites affecting people

Straw Itch Mites : Pyemotes tritici commonly breed in stored grain, dried beans and peas, wheat

straw, hay and other dried grasses . frequently a problem for people doing landscaping or feeding

horses and other livestock. The mites are actually beneficial because they attack insects that

feed on stored grain and similar materials. People who handle

mite-infested materials will be attacked. The bites of straw itchmites are characteristically found on the trunk of the body and onthe arms.

Bird Mites Ornithonyssus sylviarum

Dermanyssus gallinae, the chicken mite (or red mite of poultry House Dust Mites Dermatophagoides pteronyssinus D. farinae
http://www.ces.ncsu.edu/depts/ent/notes/Urban/mites.htmhttp://www.ces.ncsu.edu/depts/ent/notes/Urban/mites.htmhttp://www.ces.ncsu.edu/depts/ent/notes/Urban/mites.htm


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Relieving the Itch of Mite Bites

When mites attach to skin, the saliva they secretecauses the intense itch that may be felt for several daysafter the mite is no longer attached.

As soon as possible after walking through chigger-

infested areas or being exposed to other mites, youshould bathe in hot, soapy water and scrub down with a

wash cloth.

to relieve itching

Oral antihistamines Application of a hydrocortisone cream to bites


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Jun 13 kuliah S 1 FK dr Teguh WS

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