1. helminths
CESTODA
TREMATODA
NEMATODA

2. 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

3. 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

4. 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……

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

6. 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

7. 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

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

9. diphyllobothrium

10. 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

11. 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

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

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

14. 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

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

16. 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

18. 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

19. Abdominal discomfort
Fever

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. LIFE CYCLE OF SPIROMETRA… Spp

28. 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

29. 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

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

31. 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

32. 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

33. 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)

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

35. 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

36. 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

38. 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

39. 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

40. 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

41. 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