helminths CESTODA TREMATODA NEMATODA

Helimenths are worm like parasites and includes 2 phyla Platyhelimenthes Cestoda trematoda Nematihelimenthes nematoda Cestodes are dorsiventrally compressed flat worms and so they are called tape worms

cestoidea Pseudophlylidea diphyllobotridiae Dyphyllobotrium D.latum Spirometra S.mansoni S.theileri Cyclophyllidea Hymenolepidae Hymenolepis H.Nana, H.diminuta Diphylidiiae Diphylidium , D.caninum Teniidiae Taenia T.solium, T.saginata Echinococcus E.granulosua,E,mulilocularis,E.vogeli

GENRAL CHARECTERS OF CESTODA segmented , dorsiventrally compressed Varies from few cms to mts Hermaphrodites, complete segments Coelom, respiratory € circulatory systems absent Excretory € nervous sys present……

Morphologic forms € morphology Morphologic forms include Adult worm: Scolex Neck strobila Egg: Larva: Cysticercous • cysticercoid Coeneures • coracidium Procercoid • pleurocercoid Hydatid cyst

Adult worm morphology Scolex: it is a distended organ Pseudophyllidiens consists a pair of longitudinal grooves called bothria Cyclophylidiens consists of 4 suckers, occasionally rostellum is present……… Neck:pseudophylidiens neck is thin un segmented longer than head. Cyclophyllidiens , short fragile, 3-7mm Strobila 3 types of proglottids Immature proglottid: present near neck Immature…. male and female sex organs Mature proglottid: Larger than prev.. Well differentiated sex organs At times 2 sets

Gravid proglottid: lies most distal Male genital organs – dorsal, Multiple testes Vas efferentia Vas deferens—genital atrium………. Female genital 0rgans- ventral Ovary bilobed Oviduct Spermatic duct Ootype Uterus Gravid proglottid: lies most distal Uterus filled with fertilized ova

Egg……. Pseudophllidien Cylophyllidien Non operculated Ovoid Initially not embrionated Ciliated embryo formed later Cylophyllidien Non operculated 2 coverings Inner embryophore Thin shell membrane

diphyllobothrium

Pseudophyllidien tape worms diphyllobotrium(leaf like structures having 2 sucking org) Identified by BONNET life cycle by JANIKE € ROSEN Common names: fish tape worm , dog tape worm Epidemiology 9 million people in world Poor sanitation Geographical dist Not so common in India, 1st case 1998 Vellore More prevalent in US, Canada, Europe, Japan

Habitat Morphology Scolex: Adult worm Neck Small int of fish eating mammals, mostly man Adult worm 10 m, 3000 proglotids , ivory colored Scolex: Almond shaped 2-3mm*1mm 2 slit like grooves….. Neck Longer than head

Strobila 3000 above proglotids Immature Mature Gravid Coiled rosette patterned uterus….. • More than a million eggs a day

Egg Yellowish brown 70*45µm Bile stained Embryonated Operculated Doesn’t float on Saturated salt solution It is non infective to man

Larval stages Coracidium Procercoid Pleuricercoid 1st stage larva Develop in water Procercoid 2nd stage larva Develop in copepods Pleuricercoid 3rd stage larva Devolop in fresh water fish

Adult worm resides in small intestine Lays operculated eggs Faecus Ciliated embryo—1-2wks Damp soil for months

Life cycle of diphyllobotrium Has a single definitive host: any mammal which feeds on fresh water fish Intermediate host 1st intermediate host: small copepods , mainly Diaptomous, cyclops Fresh water fish which feeds on copepods

CLINICAL MANIFESTATIONS Most of the infections r by a single worm, vague r no manifestations Manifestations include 1. fatigue € weakness 2. Diarrhoea 3. Numbness of extremities 4. Wt loss

Abdominal discomfort Fever

Complications Adult worm has high affinity for vit B-12 Also interferes with combination of B-12 and intrinsic factor Results in hyperchromic ,macrocytic, megaloblastic anemia……PERNICIOUS ANEMIA Which manifests as Dyspnoea Glossitis Fatigue Tachycardia

Reservoir, source, transmission Host immunity plays no role…………. Good Prognosis……… Reservoir, source, transmission Man is opportunistic host & reservoir Transmission orally ,eating under cooked fresh water fish Eating raw liver of fish sevile

Diagnosis….. Lab diagnosis Patients with pernicious anemia, from endemic area, habit of eating raw fish, or history of eating under cooked fish Lab diagnosis Mostly parasitic Demonstration of egg, microscopically Direct wet mount preparation At times chains of proglottids passed along with stools Identified by the presence of rosette uterus

Treatment Prevention & control PRAZIQUANTEL NICLOSAMIDE PRIZIQUANTEL Orally, in single dose, 5mg-10mg/Kg Bodywt Vit B-12 parenterally Prevention & control Thoroughly cooked fish, or freezing at -1o◦c for 24 hrs to 48hrs…… Avoidance of eating raw & under cooked fish Prevention of contamination of lake, river water or reservoir with human faeces Control of copepods

spirometra Introduction Not a common human parasite Medically imp species include Spirometra mansoni Spirometra theileri Spirometra erinance It is quite related to Diphyllobotrium Man is an accidental host & acts as an intermediate host Measures about 4cms-10cms in length White in color

Habitat Generally ,Subcutaneous tissue, orbit, muscles, lymph nodes, any part of the body………… Hosts: Definitive host : dogs & cats Intermediate host: 1st intermediate host: copepods, body cavity , procercoid 2nd intermediate host: fish frog snake, various organs , plerocercoid

drinking infected water TRANSMISSION drinking infected water Eating raw or poorly cooked amphibians Using infected frog or snake flesh as poultice Plerocercoid larva –spargana-sparganosis Occurs , SE Asia, N&S America , Sparangnosis

LIFE CYCLE OF SPIROMETRA… Spp

SPARANGNOSIS sparangnum 1. Procercoid larva liberation 2. Frog /snake tissue , Migration-subcutaneous tissue& other organs Encysted in fibrous nodules,painfull-2cm dia, Serious, when end up in brain, eye,lymphatic system

Prevention & control Diagnosis Definite diagnosis is made only after surgical removal of nodule & demonstration of larva Absence of suckers and hooklets differentiates 4m others……. Species diagnosis is by feeding living cats with spargana and observing the adult Prevention & control Filtering water Avoid consumption/contact with raw flesh, which might harbour plerocercoid larva

Treatment Rx Surgery is the only treatment Includes surgical removal of plerocercoid larva & nodule containing larva

CYCLOPHLLIDIEN TAPE WORMS GENUS HYMENOLEPIS GENUS TAENIA GENUS ECHINOCOCCUS GENUS DIPYLIDIUM General characters These have 4 suckers, a rostellum at times with hooks T. worms of medical importance belong to Taenioidea Flattened body , Simple suckers Non operculated egg

Family hymenolepididiae genus hymenolepis Segments broader than long Testis 1-4….., Sac like unilateral uterus Causes hymenolepiasis in humans Of medical importance include H. nana H . diminuta

HYMENOLEPIS NANA Dwarf tape worm Single host HABITAT Ileal portion of small intestine , man, rat ,mouse MORPHOLOGY Small tread like, 10-40cms Consists of Scolex Neck Strobila(//200)

SCOLEX Globular 4 suckers, rostellum (retractable), 20-40 hooklets NECK Long ,posterior to head STROBILA 2O0 segments O.3mm*0.9mm Monoecious 2wk lifespan……. 1000-2000 AW in infected person INFECTIVE FORM Egg of the worm

EGG Colorless Oval 30µm-45µm in dia 2 membranes……….. Space Inner membrane 2 poles, polar filaments 4-8 Onchosphere-3 pairs of hooklets, Eggs released by disintegration of gravid LIFE CYCLE Completed in single host, no intermediate host, man , mouse, rat acts as both def & intermediate host. 2 types of life cycles Direct Indirect

DIRECT CYCLE Ingestion- eggs / proglottids of eggs Small int lumen-oncosphere release- villus penetration- cysticercoid development.(4 days) villus rupture– free cysticercoid attaches another villus……….. > 2weeks- adult worm Strobilization 30 days after infection….. Egg hatch in the intestine-auto infection

INDIRECT CYCLE It is with grain flour eating beetles, fleas , moths Ingestion of egg…….stimulation of onchosphere Enters body cavity, transforms into CYSTICERCOID Larva Accidental ingestion by man, develops into Adult worm PATHOGENICITY& clinical manifestations……… Tolerated even in large numbers CL. Manifestations due to Allergic reaction include, pruritus of nose and anus Anorexia , Abdominal pain. Diarrhoea, Headache, dizziness , restlessness, convulsions

HOST IMMUNITY Direct cycle –strong humoral & cellular immunity………. Incapable of destroying , worms which already invaded the gut wall •prognosis is excellent even without treatment EPIDEMIOLOGY&GEOGRAPIC DIST 36 million all over the world 4-10 yrs children Common in temperate than tropical Ubiquitous, SA, SE, lat amrca ME asia In India gujrt, AP, TN, chandigarh , haryna high incidence in WB

RESERVIOR SOURCE TRANSMISSION… OF DISEASE Man is main reservoir Human feces main source Transmission – faeco oral ingestion Contamination of food & water Rarely ingestion with fleas

LAB DIAGNOSIS Egg demonstration in faeces by direct microscopy, salt flotation& formalin ether conc… methods. eosinophillia TREATMENT PRAZIQUANTEL NICLOSAMIDE PROPHYLAXIS Personal hygiene Sanitary improvements Un contaminated food & water Rodent control