Parasitic Helminths Tapeworms T a e n i a s i s ( Penyakit Cacing Pita )

Taenia solium ( pada babi )

MorphologyAdult : 2-4 m long, 700-1000 segments: Scolex Neck Immature segment Mature segment Gravid segment

Taenia saginata

Taenia saginata (beef tapeworm) ( pada binatang sapi 4- 25 m , 1000-2000 segments Scolex Neck Immature segment Mature segment Gravid segment

TAENIASISAgen penyebab: Tanea soleum - babi T. saginata - sapi

Dalam siklus hidupnya menyebabkan infeksi pd manusia, tdp 2 stadium: stadium dewasa/taeniasis - intestinal infection stadium larva/cystiserciasis; cysticercosis - infeksi pada jaringan

Morfologi

T. solium T. saginata

Body length 2-4m 4-8m

Segment 700-1000, thin 1000-2000, thick

Scolex rostellum with hooks no rostellum and hooks

Morfologi

T. solium T. saginata

Mature segment

Ovary()

Gravid segment

Uterine branches

Classification of helminthsNematodes (roundworms)Platyhelminthes (flatworms) Trematodes (flukes) Cestodes (tapeworms)

Epidemiologi Hospes definitif ( penjamu/ resrvoir ): manusiaPenyebaran : seluruh dunia, terutama Amerika latin, Afrika, Asia Tenggara, Eropa bagian TimurPenularan : menelan daging babi (T.sol.) atau sapi (T.sag.) mentah/tidak dimasak dg baik. Cysticercosis ( sirtiserkosis): - langsung, dan tidak langsung dari ma-mi tercemar

EpidemiologiT. saginata:Widespread in cattle breeding areas of the world. Prevalence >10% in some independent states of the former Soviet Union, in Near East, and in central and eastern Africa.Lower rates in Europe, Southeast Asia, & South America

T. solium:Prevalent in Mexico, Central and South America, Africa, SoutheastAsia,and the Philippines

Infections in USA and Canada are found in immigrantsfrom areas where taeniasis is endemic, and in travelers who consume undercooked meats in endemic areas

Siklus Hidup Humans are the only definitive hosts for T. saginata and T. solium. Eggs or gravid proglottids are passed with feces ; the eggs can survive for days to months in the environment. Cattle (T. saginata) and pigs (T. solium) become infected by ingesting vegetation contaminated with eggs or gravid proglottids . In the animal's intestine, the oncospheres hatch , invade the intestinal wall, and migrate to the striated muscles, where they develop into cysticerci. A cysticercus can survive for several years in the animal. Humans become infected by ingesting raw or undercooked infected meat.

In the human intestine, the cysticercus develops over 2 months into an adult tapeworm, which can survive for years. The adult tapeworms attach to the small intestine by their scolex and reside in the small intestine. Length of adult worms is usually 5 m or less for T. saginata (however it may reach up to 25 m) and 2 to 7 m for T. solium. The adults produce proglottids which mature, become gravid, detach from the tapeworm, and migrate to the anus or are passed in the stool (approximately 6 per day). T. saginata adults usually have 1,000 to 2,000 proglottids, while T. solium adults have an average of 1,000 proglottids. The eggs contained in the gravid proglottids are released after the proglottids are passed with the feces. T. saginata may produce up to 100,000 and T. solium may produce 50,000 eggs per proglottid respectively.

Taenia saginata - The Beef Tapeworm

Taenia solium - The Pork Tapeworm

Cysticercus in pig muscle

Manifestasi klinis

Incubation period:taeniasis - eggs appear in 8-14 weekscystercosis - days to yearsSymptoms:Taeniasismild abdominal symptomsoccasionally appendicitis or cholangitis from migrating proglottidspassage of proglottids (active or passive)

Manifestasi klinis

Cysticercosis:migrating larvae may localize in eye, CNS, or cardiac tissueneurocysticercosis - severe, may be fatalheadachenauseavomitingepileptiform seizureshydrocephalus - either by accumulation of CSF behind cyst or my inflammatory response

Manifestasi klinisTaenia saginata < Taenia solium : sistiserkosis T.saginata jarang terjadiT.saginata , terutama cacing dewasa yg menimbulkan gangguan pada manusiaGangguan sal.cerna karena panjang cacing dalam usus ( 25 meter ) : diare, rasa lapar.Penurunan berat badan, nausea, muntah ssd makan, kolik usus, spt tukak lambung, gejala peny.empedu

Manifestasi klinisCysticercosis occurs in humans after the ingestion of T. solium eggs

Embryonic metacestode migrates from the intestine and can lodge ina number of tissue sites such as the brain, muscle, and eyes with proclivity for the brain

The clinical course largely depends on the endurance of the parasite inside the tissue and on the ensuing inflammation

In the brain parenchyma, the intruding cysticercus might be destroyed within a few days by host immune mechanisms or remainviable in the brain for > 10 years

Manifestasi klinisCysticercosis can affect humans at any age Most common during the 3rd and 4th decades of lifeAbout 10% occur in children

In infants initial signs of cysticecosis in infants is generalized seizureCT with contast or T2-weighted MRI isolated cystic lesion in the brain parenchyma

Typically the lesion disappears spontaneously 2-3 months later, but insome granuloma cacification (permanent sequela)Isolated lesion is most common; some children have two-several cysts

Cystcercotic encephalitis is a severe form of CNS cystcercosisthat occasionally occurs in children, particularly adolescent girls

Manifestasi klinis

In adults neurocysticercosis is quite different:

Multiple brain cysticerci, variable immune response, chronicinflammation, chronic persistence of many active cysts, vasculitis and protean clinical picture

Epilepsy occurs in 50% of cases; intracranial hypertension in 30%

Occular Cysticercosis: Subretinal area or vitreous chamber

Muscular cystcercosis: Rare in both children and adults; usuallybenign course

Cysticercosis in brainCystcercosis in eyeCysticercosis in subcutaneous tissues and muscles

DiagnosisTaeniasisstool examinationanal swabgravid segment examinationCystisercosisbiopsy funduscopyX-ray, B ultrasonic, CTSerological tests

CYSTICERCOSIST. saginata egg

Diagnosis

Taeniasismicroscopic identification of eggs and proglottids in feces after 3 monthseggs do not distinguish speciesCysticercosisSerologyCT for visualization of calcified cystsMR for cysts in fourth ventricle

Pengobatan

TaeniasispraziquantelCystercosispraziquentel if active cystercosis, but only under hospitalization due to acute inflammatory reaction; steroids given to control inflammationsurgicalshunt - ventriculoperitoneal shunt to drain CSFcyst removalendoscopic fenestration (hole in cyst wall)

PengobatanIntestinal T. solium and T.saginata infection: Praziquantel - (5-10 mg/kg once)

Neurocysticercosis:Albendazole - 15 mg/kg/day (maximum, 800 mg/day) divided into two doses X 8 daysTwo months later, if repeat imaging studies show cysts: Praziquantel in a total dose of 75mg/kg divided in three doses for 15 days. Repeat imaging studies in two months

PencegahanPrevention/Control

EducationIdentification and immediate treatment of infected individualsFreezing meat at -5C (23F) for > 4 days effectively kills cysticerciIrradiation

TaeniasisTapewormCysticercosispoorhygienepoorsanitationingestion ofundercooked pork

Taenia saginata & Taenia solium Laboratory Findings/DiagnosisCT and MRI are the most relaible tools for the diagnosis of neurcysticercosis

Serologic tests are unreliable (cross reactivity with antigens of other parasites)

Serology is highly specific for CNS inection when tests are performed on CSF

TapewormsDefinitive hosts: harbor adult wormsIntermediate hosts: harbor tissue cysts (containing worm heads)Humans acquire infection two ways:ingestion of eggs from feces (to acquire tissue cysts)ingestion of tissue cysts in undercooked meat (to acquire a tapeworm)= Intermediate host

= Definitive host

TAENIASIST. saginata

TAENIASISTanea soleum

TANEIASISEpidemiologyReservoir: humans definitive host for both T. saginata and T. soleumOccurrence:worldwidehighest in Latin America, Africa, SE Asia, Eastern EuropeT. soleum rare in US, Canada, UK, but increasingly recognized in immigrants

TANEIASISEpidemiologyTransmission:T. saginata - ingestion of raw or undercooked beef or beef products containing cysticerciT. soleum - ingestion of raw or undercooked pork or pork products; measly porkCysticercosisdirect transmission of eggsdirect contact (mouth-mouth)autoinfection - reverse peristalsis of eggs or proglottids in intestineindirect by contaminated food or water (eggs)

III. PathogenicityTaeniasis intestinal descomfort: vomiting, diarrhoea or constipation, loss of appetite, appendicitis and intestinal obstructionCysticercosisThe methods of infecting eggs: auto-infect oneself in body; auto-infect oneself outside body; infect from other person

5.6 The Parasitic HelminthsTapeworms, flukes, and roundwormsAdults large enough to be seen with the naked eyeFrom 1 mm to 25 m in lengthMicroscope is necessary to identify eggs and larvaeTwo major groups: Flatworms and Roundworms

Life Cycles and ReproductionFertilized egg (embryo), larval, and adult stagesIn most, adults derive nutrients and reproduce sexually in a hosts bodyNematodes- separate sexesTrematodes- separate sexes or hermaphroditicMust complete the life cycle by transmitting an infective form to the body of another hostLarval development- intermediate (secondary) hostAdulthood and mating- definitive (final) host

FlatwormsPhylum PlatyhelminthesThinOften segmentedSubdivisionsCestodes (tapeworms)Trematodes (flukes)

Among the most common tapeworms in humans are the pork tapeworm, the beef tapeworm, the fish tapeworm, and the dwarf tapeworm. Infections involving the pork and beef tapeworms are also called taeniasis. Length of adult worms5 m or less for T. saginata (however it may reach up to 25 m) 2 to 7 m for T. solium.

CestodesLive tapeworm larvae are sometimes ingested by consuming undercooked food. Once inside the digestive tract, a larva can grow into a very large adult tapeworm.The adults produce proglottids which mature, become gravid, detach from the tapeworm, and migrate to the anus or are passed in the stool (approximately 6 per day). Additionally, many tapeworm larvae cause symptoms in an intermediate host. For example, cysticercosis is a disease of humans involving larval tapeworms in the human body.

Clonorchis sinensis

Figure 5.29

Life Cycle of Human Liver FlukeEmbryonated eggs are discharged in the biliary ducts and in the stool. Eggs are ingested by a suitable snail intermediate host; the egg releases miracidia, which go through several developmental stages (sporocysts, rediae, and cercariae).Over 100 species of snail are suitable intermediate hosts The cercariae are released from the snail and after a short period of free-swimming time in water, they come in contact and penetrate the flesh of freshwater fish, where they encyst as metacercariae.

Life Cycle of Human Liver FlukeInfection of humans occurs by ingestion of undercooked, salted, pickled, or smoked freshwater fish. After ingestion, the metacercariae excyst in the duodenum and ascend the biliary tract through the ampulla of Vater. Maturation takes approximately 1 month. The adult flukes (measuring 10 to 25 mm by 3 to 5 mm) reside in small and medium sized biliary ducts. In addition to humans, carnivorous animals can serve as reservoir hosts.

RoundwormsPhylum NematodaElongateCylindricalUnsegmentedIn dogs: Roundworms, tapeworms, hookworms, whip worms and heartworms.Human: potentially all of these; also pinworms and many others.

General Worm MorphologyMost developed organs are those of the reproductive tractSome degree of reduction in digestive, excretory, nervous, and muscular systemsMost have thick cuticles for protection and mouth glands for breaking down the hosts tissue

Figure 5.30Round worms

Hookworms

HookwormThe human hookworms include the nematode species, Ancylostoma duodenale and Necator americanus. A larger group of hookworms infecting animals can invade and parasitize humans (A. ceylanicum) or can penetrate the human skin (causing cutaneous larva migrans), but do not develop any further (A. braziliense, A. caninum, Uncinaria stenocephala). Occasionally A. caninum larvae may migrate to the human intestine, causing eosinophilic enteritis. Ancylostoma caninum larvae have also been implicated as a cause of diffuse unilateral subacute neuroretinitis.

HookwormsHookworm larvae can penetrate the surface of a person's skin (usually through bare feet) and migrate through it, causing a disease called 'cutaneous larva migrans' or 'creeping eruption.' The lesions appear as red lines under the skin and sometimes break open at the skin's surface. These lesions cause severe itching. Usually, the larvae will die in several weeks and the condition will disappear. In severe cases, the larvae may make their way through the skin and enter deeper tissues. This may cause lung disease and painful muscles.

Life Cycle (intestinal hookworm infection):

Life Cycle (cutaneous larval migrans):

A Helminth Cycle: The PinwormPerson swallows microscopic eggsPicked up from another infected person by direct contactOr by touching articles an infected person has touchedEggs hatch in the intestineRelease larvae that mature in to adult worms (about 1 month)Male and female worms mateFemale migrates out of the anus to deposit eggs Causes intense itchinessRelieved by scratchingScratching contaminates the fingers which transfer the eggsEggs spread to others or the original host reinfects him or herself

PinwormsEnterobius vermicularis Use a flashlight to inspect the anal area At nightTape test: 1 inch strip of cellophane tape is pressed firmly over the anal area for a few seconds. Repeat three separate days.In morning before bathingTransfer to a glass slide, sticky side down

Helminth Classification and IdentificationShapeSizeDegree of development of various organsPresence of hooks, suckers, or other special structuresMode of reproductionKinds of hostsAppearance of eggs and larvae

Distribution and Importance of Parasitic WormsAbout 50 species parasitize humansDistributed in all areas of the worldYearly estimate of worldwide infections- in the billions

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