Trematodes

Trematodes

• Total 6 trematodes

• 3 hosts
• Man + Snail + 1 variable

• Chis - chis = Fish

• Fresh water → Fasciola

• Trema → 3 some → Fuck (fluke) and kiss (chis) → Mercy (MRCM) → wear condom (operculated egg for all) → Spinous for Schistosoma

Operculated Eggs

• Has a thin cap on top (lid).

• Mnemonic: STD.
• S - Spirometra.
• T - Trematodes.
• Exception: Schistosoma (Spinous egg).
• D - D. Latum.

• Sota hua man → late ho gaya

• terminal end sharp → blood came in urine (UB) → hematobium

• Japan has round face

Schistosoma Species

• Hosts: only humans and snails.

• Infective stage: Cercaria larva.

• Entry: skin penetration.

• Sexes are separate.

• Egg is spinous.

 

• Disease caused by Schistosoma: Schistosomiasis/ Bilharziasis

Trematode Eggs

• Lifecycle mnemonic: MCRCM.
• M - Miracidia.
• C - Cyst.
• R - Redia.
• C - Cercaria larva.
• M - Metacercaria larva.

• In Schistosoma, only MCC stages are seen

Paragonimus Westermani Lifecycle

• Involves snail, crab or crayfish, and humans.

• Eggs excreted in:
• Sputum (pulmonary involvement).
• Stools.

Clonorchis Sinensis Lifecycle

• ChlonorFish

• Involves snail, fish, or human.

• Clonorchis or Opisthorchis cause liver flukes.

• Both cause cholangitis and cholangiocarcinoma.

Species	Common Name	ㅤ
Clonorchis sinensis	Chinese liver fluke	sinensis - chinese
Opisthorchis viverrini	Southeast Asian liver fluke	viverrini - veriety - south asia
Opisthorchis felineus	Cat liver fluke	felineus - Cat
Fasciola hepatica	Sheep liver fluke	hepatica - Sheep
Fasciola gigantica	Giant liver fluke	gigantica - Giant

Intestinal Trematodes

• All involve Small intestine
• except Gastrodiscoides hominis (involve Large intestine)

Species	Type
Fasciolopsis buski	Giant intestinal fluke
Heterophyes	Small intestinal fluke
Metagonimus yokogawai	Small intestinal fluke
Echinostoma ilocanum	Small intestinal fluke
Gastrodiscoides hominis	Intestinal fluke

Nematodes

Classification by Habitat

• Large Intestine → Are Oviparous
• Trichuris.
• Enterobius.
• Enterooo () nn Thirichoori ()

• Small Intestine → Are Oviparous
• These also have a lung stage.
• Roundworm
• Hookworm
• Strongyloides (Ovo viviparous)
• Small room → need other room → lungs
• Round () hook () vach strong () ayi pidichu

• Somatic → Viviparous
• Filaria
• Trichinella
• Dracunculus
• Dracula () fly () cheyth → thirichini illa (Trichinella)

Nematode Eggs/Larva

• All diagnostic form is Embryonated egg except
• Trichuris → Unembryonated egg
• Strongyloides → No eggs → Rhabditiform larva
• Trichenalla → larva in muscle
• Dracula → L3 larva

• Treatment for all is Albendazole, except
• Strongyloides Stercoralis → Ivermectin
• Dracunculus Medinensis → Eradicated

• IDA → hookworm.

• Vitamin B12 deficiency→ D. latum

• Skin penetration (SAS) is a mode of infection for:
• Schistosoma.
• Ancylostoma
• Strongyloides.
• Strong () anchor () to skin ()

Cutaneous Larva Migrans

• M/c/c = Ancylostoma braziliense

• Other causes
• Ancylostoma caninum
• Necator americanus
• Strongyloides species

Ascaris Lumbricoides

Trichuris trichiura

• Uuriya whip () →
• Beat coconut ()
• Beat barrel ()
• Beat back → dysentery, rectal prolapse

Enterobius vermicularis

Ancylostoma duodenale

• Anchor () eat nector () with Hook ()

Differences Between Hookworms

• Egg, Rhabditiform larvae → Same

• Adult worm, Filariform larvae → different

Strongyloides Stercoralis

Trichinella Spiralis

Dracunculus Medinensis

Formalin Sedimentation test

Filaria

• Microfilariae can be sheathed or unsheathed.

• Examples

• sheathed → LBW

Microfilariae

Clinical Manifestations of Wuchereria bancrofti

• Etiology:
• Wuchereria bancrofti (Most common)
• Brugia malayi
• Brugia timori

• Vectors:
• Culex:
• Bancroftian filariasis (most common)
• Mansonia:
• Brugian filariasis
• Mnemonic: Mansoonil (Mansonia) cutex (culex) itt irunnapo manthu () vannu

• Epidemiology:
• Microfilaria enters culex mosquito → Undergoes Cyclodevelopmental Change (no multiplication) → Only change in form → Forms the Infective form: 3rd stage larva of developing microfilaria (L3)
• Portal of entry: Skin
• Localization: Inguinoscrotal lymphatics
• Reservoir: Humans with microfilaria in blood

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• Clinical Presentation:
• Asymptomatic
• Acute Dermatolymphangitis (ADL)
• Lymphedema
• Hydrocoele
• Causes Chyle in urine (Chyluria).

Diagnosis:

• USG scrotum for filarial dance sign.

• Antibody tests: non-specific.

• Antigen tests: specific.
• ELISA for ADI12Ag.
• ELISA for OgD4C3Ag9
• ogod D4 (dancing) 3 filaria - aadi

• Transmission assessment survey

Peripheral Blood Film:

• Diagnostic, surveillance

• Sample collected from 10 PM till 2 AM

• Concentration Method: (Most sensitive)
1. Membrane filtration
• Most common
2. Centrifugation / Knott method (2% formalin)
• Blood sample lysed in 2% formalin (knott’s technique)
• Not (knott) in form (formalin) for 2 (2%) days

DEC Provocation Test:

• Clinically diagnostic

• 100 mg oral DEC → 1 hr → Peripheral blood smear

Treatment:

• DEC: 12 doses at 6 mg/kg/dose, total 72 mg/kg

Prevention:

• Best Method for Control of Filariasis:
• Deweeding of large water bodies

• Target: Elimination by 2027

Strategy:

• Mass Drug Administration (MDA)
• IDeA



• DEC medicated salt:
• 1-4 gms DEC/kg
• All filaria DEC except onchocerca → ivermectin
• Fila → Iver

Indicators:

1. Microfilarial Rate:
• No. of people with slide positive
  Total slides examined in population
• Indicates microfilaria (Mf) in blood.

2. Filarial Endemicity Rate:
• % people showing Mf in blood or disease presentation or both.
• Indicates disease prevalence in area.

3. Microfilarial Density:
• No. of Mf per unit volume of blood (20 cu.mm).
• Indicates intensity of infection.

Elimination of Lymphatic Filariasis Criteria

• Two criteria

• Children born after initiation of ELF programme
• Free from circulating antigenemia

• Microfilaria carriers
• < 1%

Complication:

• Mazzotti Reaction:
• Hypersensitivity to DEC in onchocerciasis (River Blindness)
• Black fly
• C/f: Urticaria, skin rashes
• Not seen in India so we dont check for mazotti reaction
• Because Onchocerciasis is not seen
• Mnemonic: Mazootti → Blind () aalu black fly () ne kollan Vetti Vetti (mazootti) → oru desk vetti (DEC)

Brunners Classification (Stages)

• Leg become Bun (B Runners) like

• Subclinical (Latent):
• Excess interstitial fluid
• no visible signs.

• Stage I:
• Pitting edema.

• Stage II:
• Non-pitting edema.

• Stage III:
• Edema with irreversible skin changes.
• Stemmer’s Sign:
• Inability to pinch skin (diagnostic).
• Hard like stem → cannot pinch
• Buffalo Hump:
• Loss of ankle contour.

Investigations

• Gold Standard:
• Water plethysmography (measures limb volume).
• Mild: < 20% volume increase.
• Moderate: 20-40% volume increase.
• Severe: > 40% volume increase.

Management

• Skin Care:
• Protect skin during activities (chopping, gardening).
• Never walk barefoot.
• Use electric razors for hair removal.
• Prevent dry skin.
• Treat cuts promptly with antibiotics.
• No blood sampling from affected limb.
• Use sunscreen.

• Decongestive Lymphedema Therapy (DLT):
• Phase 1 (Intensive):
• Supervised
• MLD: manual lymphatic drainage
• MLLB: multilayer bandaging
• Phase 2 (Maintenance):
• Self-care.

• Exercises:
• Beneficial: Slow, rhythmic isotonic (e.g., swimming).
• Worsens with: Vigorous, anaerobic, isometric exercise.

• Surgery:
• TOC
• Lymphovenous anastomosis (creates bypass).
• Debulking (reduction procedures):
• Not done

Brugia malayi

• Zoonotic infection from monkeys via Mansonia mosquitoes.

• Differences from Wuchereria bancrofti:
• Leg involvement below the knee.
• No genital involvement.
• No hydrocele.

Onchocerca volvulus/Convoluted Worms

• Transmitted by Blackflies.

• Causes black, thick skin.

• Clinical features:
• Dermatitis.
• Leopard skin.
• Onchocercoma.
• Eye involvement
• River blindness
• Sclerosing keratitis

• Lymph node involvement (Hanging groin).

• Lab Diagnosis: Mazotti skin test.

• DOC: Ivermectin.

Loa Loa

• Also known as Calabar/fugitive swelling.

• Hypersensitivity reaction to adult worms.

• Clinical features:
• Subcutaneous tissues swelling.
• Pruritus.
• Fever.

• Treatment: DEC.

Summary of eggs

Doesn't float

• Strongyloids

• Unfertilised egg of Ascaris

• Intestinal tapeworm

• Taenia