3Class insecta Anoplura (Lice) Heteroptera Siphonaptera D i p t e r a Nematosera(mosquitoes, black flies)Brachisera(flies)Anoplura(Lice)CinsPediculusPhthirusHeteroptera(Bugs)CinsCimexOeciacusTriatomaRhodniusPanstrongylusSiphonaptera(Fleas)CinsPulexCtenocephalidesCeratophyllusArchaeopsyllaXenopsyllaTungaCinsAnophelesCulexAedesSimuliumPhlebotomusLutzomyiaMusca, Glossina, Calliphora, Cochliomyia,Cordylobia, Lucilia, Sarcophaga,Wohlfahrtia, Gasterophilus, Hypoderma,CuterebraSiphonaptera (fleas) Pulex, Ctenocephalides, Ceratophyllus,CinsMusca, Glossina,Calliphora,Cochliomyia,Cordylobia,Lucilia, SarcophagaWohlfahrtia,GasterophilusHypoderma,Cuterebra
5Lice ● Wingless insects. ● Permanent ectoparasite. Morphology● Wingless insects.● Permanent ectoparasite.● Host specific parasites,each lice species is found on only a single species of host.Lice
6Lice●Incomplete metamorphosis (egg-nymph-adult)●Spend their entire life on the host● Two species of lice infest humans, one of which is divided into two subspecies.
7● Lice are dorsoventrally flattened insects, Morphology● Lice are dorsoventrally flattened insects,about 1.5–4mm in length, wingless, with reduced eyes .●The head has short (five-segmented) antennae, piercing and sucking mouthparts, and strong claws designed to cling to hairs.Lice
8Lice ● Lice develop from eggs (called nits) glued to hairs. ● The hatched louse grows and molts throughthree nymphal stages to become an adult.● Lice remain on a host permanently; bothmales and females are hematophagous andrequire frequent blood meals.
9Life cycle of lice Egg Nimph Adult ● Life cycle 1st instar nimf2nd instar nymph3rd instar nymphAdult● All stages are found onhost body● Can not survive out of thehost
10LiceEpidemiology● Among the various species of lice only the body louse is a vector of human diseases.It transmits-Typhus fever (caused by Rickettsia prowazekii)-Relapsing fever (caused by Borrelia recurrentis)-Trench fever (caused by Bartonella quintana).-Tularemi (caused by Pasteurella tularensis)
11Pediculus humanus capitis (Head louse) ● To day in our region the medical importance of lice is not due to their vector function, but rather to the direct damage caused by their bites● Oval body, length 2.2–4.0mm, morphology very similar to the body louse.● Nits are 0.5–0.8mm long.The nits are glued to the base of the hair near the skin.
12Pediculus humanus capitis (Head louse) ●Duration of development from nit to adult is 17 days.● The lifespan of adults on human host is about one month, survival off host at room temperature is for up to one week.
14Pediculus humanus capitis (Head louse) ● Occurs worldwide; epidemic-like outbreaks of head louse infestation are observed regularly, especially in schools and kindergartens, homes, groups of neglected.● Transmission is in most cases by personal contact (mother-child contacts,children playing, etc.), but can also be mediated by such objects as combs,caps, pillows, head supports, stuffed animals, etc.
15Pediculus humanus capitis (Head louse) Clinical manifestation● Pruritus and exforiations in the scalp area, nits on hairs,especially in the retroauriculararea,scalp dermatitis, especially at thenuchal hair line: small papules, moist exanthema, and crusting areexemples of clinical manifestation.
16Pediculus humanus capitis (Head louse) ● It can be diagnosed by the determination of symptoms and detection (direct or with magnifier) of lice and/or nits, especially around the temples,ears, and neck
17Pediculus humanus capitis (Head louse) Treatment● In group outbreaks, all contact persons must be treated concurrently,e.g., entire school classes and the families of infested children.● Rinsing the hair with 5% vinegar in water followed by mechanical removal of the nits with a “louse comb” is a supportive measure.
18Pediculus humanus capitis (Head louse) ● Because eggs hatch 6–9 days after oviposition, if a pediculicide is used, treatment is recommended to be repeated at least once and this after 10 days, when all lice have hatched from the eggs, a third treatment on day 5 is recommended.● Patients were treated by chimicals,natural products,enzyme based products,combs,hot air, silicone-based lotions
19Pediculus humanus corporis ● Oval body, length: 2.7–4.7mm.Very difficult to distinguish from head louse● Localization mainly in clothing, where nitsare deposited on fibers. These lice contact tothe host only for blood meals.
20Pediculus humanus corporis ● Duration of life cycle is about three weeks.lifespan on host usually is four to five weeksrarely as long as two months.● Bite reactions on the body, especiallyaround the underwear, are indicative of bodylouse infestation. diagnosis is made afterinspecting clothing for nits and lice.
21Phthirus pubis (Crab or Pubic Louse) ● Infestations are more frequent in adults than in children and in men more frequently than inwomen.● This louse species can be readily differentiated from the head or body louse: small, length 1.3–1.6mm,with trapezoid or crablike body form
22Phthirus pubis (Crab or Pubic Louse) ● The parasites are most often found on hair of the pubic and perianal region, more rarely on hairy areas of the abdominal region, hairs around the nipples, beard hairs, eyelashes, andeyebrows.●The life cycle takes three to four weeks. crab lice die at room temperature within two days.
24Phthirus pubis (Crab or Pubic Louse) ● Transmission of crab lice is almost solely by way of close body contact (sexual intercourse in adults or parent-child contact).● Indirect transmission on commonly used beds, clothes, etc. is possible, but isnot a major factor.
25Phthirus pubis (Crab or Pubic Louse) ● Pruritus and scratches in the genital area and other infestation sites . In some patients typical slate-blue spots, a few mm to 1cm in size can be observed as a clinical manifestations● It can be diagnosed by detection of lice and nits in the pubic area and other possible localizations.
26Pediculus humanus ● Pediculus humanus capitis(head louse) localization and sites of ovipositionHair on the head, rarely on beard hairs or hairy sites on upper body.● Pediculus humanus corporis(body louse)Stitching, seams, and folds in clothes, especially whereit is in direct contact with the body.
27● Phthirus pubis (crab louse) localization and sites of ovipositionHair of pubic area, more rarely in theabdominal and axillar regions, beard,eyebrows, and eyelashes.
29Cimex lectularius The bedbug, occurs worldwide. ● They are about 3–4mm long● Dorsoventrally flattenedbodies● Greatly reduced wings● A bloodsucking proboscis thatcan be folded back ventrally
30Development from the egg Life cycle● Egg● LarvaFirst stage larvaSecond stage larvaThird stage larvaForth stage larvaFifth stage larva● AdultDevelopment from the eggthrough five larval stages tothe adults takes about oneand a half months undersuitable conditions, but canbe extended to as long asone year.
31Cimex lectularius ● Bedbugs require several blood meals during development and egg production.● Their ability to starve for as long as a year means they can persist for long periods in rooms, hiding by day (under mattresses, behind furniture,in cracks in the walls, etc.) and emerging at night questing for a blood meal.
32● The bedbug is therefore often not considered Cimex lectularius● The bedbug is therefore often not consideredWhen diagnosing skin lesions. Bedbugs live on humanblood.Especially in repeated infestations, their bitesinduce hemorrhagic or urticarial-papulous reactions,often visible as lesions arranged in groups or rows.● Diagnosis is based on skin lesions and detection ofbugs in the vicinity. Therapy is symptomatic.
34Pulex irritans ● This flea is about 2–5mm long, ● Laterally flattened, ● Wingless● Have three pairs of legs, the hindmost of whichare highly adapted for jumping.Pulex irritans
35Pulex irritans ● The mouthparts form a beaklike proboscis for Bloodsucking.● The antennae are short.● Combs of spines (ctenidia)can adorn the head andfirst thoracic segment
36Pulex irritans● Fleas are ectoparasites in humans and vertebrate animal species.● Frequent blood meals are needed during the one to three month egg-laying period● Most of the eggs fall off the host and continue to develop in cracks and crevices.
37Life Cycle adult flea varies from few weeks to one year. Larva Pupa ● The life cycle of anadult flea varies fromfew weeks to one year.Life CycleEggLarvaPupaAdult.
38Pulex irritans ● The fleas in this group are periodic ectoparasites. ● The adult stages remain for the most part on the host while the larva and pupa live in the vicinity of their hosts in the so-called“nest habitat.”
39Pulex irritans● In certain regions, fleas serve as vectors for viruses, bacteria,rickettsiae, protozoa,and helminths.● Fleas are best known as the vectors of the causative agent of “plague”,Yersinia pestis (rodent-infesting fleas of the genus Xenopsylla)
40Pulex irritansIn the clinical manifestations,dermal reactions to fleabites go through several phases:1-Early reaction: within five to 30 minutes after the bite, a dotlike hemorrhage (at the site of the bite) and a reddening (erythema) with or without a central blister are formed, accompanied by pruritus.
41Pulex irritans2-Late reaction: after 12–24 hours, itching papules form, surrounded by erythemas up to palm-size, some with a central blister or purulent pustule; thisreaction persists for one to two weeks
42Pulex irritans● Sites for lesions are extremities, neck, nape of neck,shoulders,less often the trunk.Reactions are usually in multiple groups,● A diagnosis is given based on the skinlesions and the case history
43Pulex irritans symptoms of plague Skin reaction after flea bite Skin symptoms of plague
44Tunga penetrans Tunga penetrans is causative agent of ● Fleas of the Family TungidaeTunga penetrans is causative agent oftungaosis (tungiasis)● Infest humans and animal species.● They live in sandy soil.
45Tunga penetrans● They penetrate the skin head first, then swell up within one to two weeks, sometimes reaching the size of a pea, from their original size of 1–2mm in length.● They lay eggs over a period of about twoweeks, and then die while still under the skin.
46Tunga penetrans ● Clinical lesions are mainly on the soles of the feet and between the toes, more rarelyon other parts of the body.● Lesions are reddened, pea-sized, painfulnodules with a craterlike central depression.Inflammatory and sometimes purulentinfiltration of the lesions can be seen
48Tunga penetrans● The diagnosis is based on the characteristic skin lesions and can be confirmed by parasitological or histological examination of the material removed from the sores.
49Tunga penetrans● Treatment consists of mechanical removal of the female flea under local anesthesia and control of the secondary infection.● Topical application of ivermectin is also effective.● Prevention demands that shoes that fit andclose properly be worn.
50-Spotted fever (Rickettsia felis) -Plague (Yersinia pestis) Fleas are competent vectors for numerous microbial pathogens of medical and veterinary importance● Ctenocephalides felis (Cat flea)Vector of-Cat scratch disease (Bartonella species)-Spotted fever (Rickettsia felis)-Plague (Yersinia pestis)● Xenopsilla Cheopis(Rat flea)● Pulex irritans(human flea)