1. Periodic 2. Subperiodic 3. Non-periodic

BLOOD AND TISSUE NEMATODES Flashcards by Arriane Cyrel (MTI)

BLOOD AND TISSUE NEMATODES aka

Filarial worms

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• Infective stage to man:

filariform/filiform/3rd stage microfilariae

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• Infective stage to vector:

microfilariae (adult worm lays eggs in the circulation; ingested by mosquito)

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• Pathogenic stage to man:

adult worm (pain is felt; disease occurrence)

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Diagnostic stages

Microfilariae: blood
Adult larvae: lymphatics

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MOT

Arthropod transmitted/mosquito-borne parasites

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threadlike, creamy, white, varies in length (2-50 cm)

Adult

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snake-like with a column of cells in the anterior to the posterior portion (develops in the vector)

larval stage

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-pre-larval stage, embryos produced by filarial worms usually found in the blood or tissues of patients with filariasis, highly motile and threadlike

Microfilaria

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Location of Microfilariae in man:

peripheral blood and lymph spaces of the skin

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a thin, translucent egg shell remnant covering the body of the microfilaria and past the head and tail

Sheath

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SHEATHED Microfilariae

Wuchereria bancrofti
Brugia malayi
Loa loa

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UNSHEATHED Microfilariae

Onchocerca volvulus
Dipetalonema perstans/Mansonella perstans
Dipetalonema streptocerca/Mansonella streptocerca
Mansonella ozzardi

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rhythmical appearance of microfilariae in the peripheral blood; maximum biting activity of the vector/active/helps in the PBS

Periodicity

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Periodicity Types:

Periodic
Subperiodic
Non-periodic

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Periodic:
➢ Nocturnal –
➢ Diurnal –

10pm to 2am

10am to 2pm

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Subperiodic:
➢ Nocturnally –
➢ Diurnally –

peak count during night time

peak count during day time

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Non-periodic:

during night time and day time

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Disease caused by

Lymphatic Filariasis

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: swelling in the scrotum that occurs when fluid collects in the thin sheath surrounding a testicle.

a) Hydrocele

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: swelling that generally occurs in one of the arms or legs

b) Lymphedema/Lymphangitis

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: condition characterized by gross enlargement of an area of the body, especially the limbs

c) Elephantiasis

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: rare condition in which lymphatic fluid leaks into the kidneys and turns the urine milky white

d) Chyluria

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✓ Asymptomatic microfilaremia
✓ Lymphangitis (inflammation) and lymphadenitis (enlargement)
✓ Orchitis (inflammation of testicle) and epididymitis; hydrocoele (swelling of scrotum)
✓ Elephantiasis
✓ Tropical pulmonary eosinophilia & allergic reaction (microfilariae)
✓ Chyluria (milky white urine)

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Laboratory Diagnosis for Filariae

1. Microscopic Examination 2. Capillary tube method 3. Immunoassay 4. Identification of adult worms

• Stains:

Wrights; Giemsa; Delafield Hematoxylin

• Negative results:

low intensity of infection; dead worms; obstructed lymphatics

provocative tests 3mg/kg single dose)- stimulates microfilariae to come out to the peripheral circulation

DEC (Diethylcarbamazine)

➢ 1 ml WB + 10 ml 2% formalin

KNOTT’S method

➢ Centrifuge at 500 x for 10 minutes

KNOTT’S method

➢ Sediment- thick and thin smears: Microfilariae & WBCs

KNOTT’S method

➢ Centrifugation of the blood sample lyzed in 2% formalin

KNOTT’S method

➢ 1 ml of fresh or anticoagulated blood is drawn up into a syring

c) Filtration: Nucleopore or Millipore membrane (5 µm pore)

➢ Lyze by adding 10 ml distilled water then pass through the Swinney filter membrane

c) Filtration: Nucleopore or Millipore membrane (5 µm pore)

➢ Examine filter membrane

c) Filtration: Nucleopore or Millipore membrane (5 µm pore)

➢ Use corneal-scleral punch, or a scalpel and needle

Skin snips: microfilariae of O.volvulus and M. streptocerca

➢ Incubate sample for 30 minutes to 2 hours in saline or culture medium then examine for microfilariae that would have migrated from the tissue to the liquid phase of the specimen

Skin snips: microfilariae of O.volvulus and M. streptocerca

➢ Use heparinized capillary tube; examine buffy coat layer

2. Capillary tube method

➢ Antigen detection- circulating filarial antigens

3. Immunoassay

➢ Molecular diagnosis using PCR- differentiation of filarial species and stage

3. Immunoassay

➢ Ultrasonography- demonstrate live worms in the lymphatics

4. Identification of adult worms

➢ Contrast lymphangiography & lymphscintigraphy using radiolabeled albumin or dextran

4. Identification of adult worms

➢ Tissue samples collected during nodulectomies (onchocerciasis)

4. Identification of adult worms

➢ Subcutaneous biopsies or worm removal from the eye (loiasis)

4. Identification of adult worms

Prevention Abaca workers-wear [?] Use of mosquito repellants and/or mosquito nets; vector control (?)

long sleeves shirts insecticides

Treatment

1. DEC (Diethylcarbamazine)/Hatrazan 2. Ivermectin (single dose of 200-400 µg/kbw for 12 days)

➢ A filaricidal piperazine derivative that kills both microfilariae and some adult worms of Wuchereria bancrofti and Brugia malayi

DEC (Diethylcarbamazine)/Hatrazan

➢ Periodic mass treatment: Single dose for 6 months

DEC (Diethylcarbamazine)/Hatrazan

➢ 6 mg/kg body weight for 12 days (bancroftian filariasis)

DEC (Diethylcarbamazine)/Hatrazan

➢ 3 – 6 mg/kg body weight up to a total dose of 36-72 mg/body weight (brugian filariasis)

DEC (Diethylcarbamazine)/Hatrazan

( 0.1% DEC or 0.3% DEC for 3-4 month )

Use of DEC fortified tablet salt

More effective if used in combination with DEC

Ivermectin (single dose of 200-400 µg/kbw for 12 days)

Relief of pain- cool the affected area

Ivermectin (single dose of 200-400 µg/kbw for 12 days)

Bancroft’s filarial worm

Wuchereria bancrofti

Malayan filarial worm

Brugia malayi

Eye worm, Loa worm

Loa loa

Bancroftian filariasis, elephantiasis of lower extremeties, lymphatics of scrotum; wuchereriasis

Wuchereria bancrofti

Malayan filariasis, elephantiasis of upper extremeties

Brugia malayi

-Loasis, fugitive swelling, calabar

Loa loa

-swelling(diameter:5- 10 cm)

Loa loa

-migration rate under the skin: 1 inch/2 mins

Loa loa

-does not cause blindness

Loa loa

- persists for 4 to 7 days and disappears

Loa loa

MALE: 4 cm in length by 0.1 mm

Wuchereria bancrofti

FEMALE: viviparous, 8- 10 cm in length by 0.2- 0.3 mm

Wuchereria bancrofti

MALE: 13-23 mm in length

Brugia malayi

FEMALE: 43-55 mm

Brugia malayi

MALE: 30-34 mm by 0.35 -0.43 mm (35mm)

Loa loa

FEMALE: 40-70 mm by 0.5 mm (60 mm)

Loa loa

➢ Microfilaria: 300 µm

Loa loa

➢ infective larvae: 200 µm

Loa loa

MOSQUITO: 6-20 days

Wuchereria bancrofti

VESSELS OF MAN: 6 mons

Wuchereria bancrofti

LIFE SPAN: 5 years

Wuchereria bancrofti

MOSQUITO: 2 weeks

Brugia malayi

VESELS: 3-9 mons

Brugia malayi

MOSQUITO: 10-12 days

Loa loa

SUBCUTANEOUS TISSUES: 1 year

Loa loa

LIFE SPAN: 1-15 years

Loa loa

Lymph vessels and lymph glands (lower)

Wuchereria bancrofti

Lymph vessels and lymph glands (upper)

Brugia malayi

Subcutaneous/Cutaneous and muscular tissues

Loa loa

blood

Wuchereria bancrofti Brugia malayi Loa loa

Culex pipiens quinquefasciatus

Wuchereria bancrofti

Mansonia spp Anopheles spp

Brugia malayi

Chrysops spp (Deer fly /Mango fly)

Loa loa

In the Philippines, the province endemic for [?] are: Camarines Norte & Sur, Bohol, Samar, Albay, Leyte, Sorsogon, all provinces in Mindanao, Quezon, Mindoro, Mt. Province, Sulu, Masbate, Palawan, Romblon

W. bancrofti

– rural type

- Anopheles minismus var, flavirostris

- urban type of bancroftian filariasis (both breed in the axils of abaca & banana)

- Aedes poecillus

(in fresh water)

- Mansonia bonnae

(rice fields)

-Mansonia uniformis

- Endemic in the Philippines (Palawan)

B. malayi

- Abaca trees accumulates stagnant water, serving as reservoir/breeding sirte for the vector mosquito

B. malayi

Tropics & subtropics

Wuchereria bancrofti

Eastern & Southwestern Pacific islands, parts of India

Brugia malayi

Tropical Africa

Loa loa

200-300 µm

Wuchereria bancrofti

220-250 µm

Brugia malayi

250- 300 µm

Loa loa

6 µm

Brugia malayi

8 µm

Wuchereria bancrofti Loa loa

Stains slightly w/ Giemsa

Wuchereria bancrofti

Stains deeply w/ Giemsa

Brugia malayi

Almost colorless w/Giemsa

Loa loa

Regular smoothly curved

Wuchereria bancrofti

Graceful sweeping

Wuchereria bancrofti

Irregular and twisted

Brugia malayi

Stiff w/secondary kinks

Brugia malayi

Irregular and twisted same as B. malayi

Loa loa

Small/short (1:1)

Wuchereria bancrofti

Large/longer (1:2)

Brugia malayi

Larger/longer (1:2)

Loa loa

Coarse/well separated

Wuchereria bancrofti

Coarse, tend to overlap

Brugia malayi Loa loa

Coarse tend to overlap

Loa loa

No nuclei pointed tip

Wuchereria bancrofti

2 widely spaced nuclei blunt tip

Brugia malayi

Nuclei present rounded tip

Loa loa

nocturnal

Wuchereria bancrofti Brugia malayi

diurnal

Loa loa

Blinding worm, convoluted filarial (causes blindness)

Onchocerca volvulus

Synonyms: Dipetalonema, Acanthocheilonema

Mansonella perstans M. streptocerca

Synonyms: Dipetalonema, Acanthocheilonema

M. perstans M. streptocerca

Ozzard’s

Mansonella ozzzardi

Onchocerciasis, onchocercosis, river blindness (blackfly breeds in the river)

Onchocerca volvulus

Angioedema, Arthralgias, Neurologic; Dipetalonemiasis

Mansonella perstans

Papular eruptions, Pigmentation

Mansonella streptocerca

Arthralgia, Adenopathy

Mansonella ozzzardi

MALE: 19-42 cm by 130-210 µm (smaller)

Onchocerca volvulus

FEMALE: 50 cm by 270-400 µm

Onchocerca volvulus

Infective larvae - 500 µm

Onchocerca volvulus

MALE: 45 mm in length

Mansonella perstans

FEMALES: 80 mm in length

Mansonella perstans

FEMALES: 65-81 mm by 0.21- 0.25 mm

Mansonella ozzzardi

Subcutaneous tissues \

Onchocerca volvulus

Inside body cavities

Mansonella perstans

Dermis of skin

Mansonella streptocerca

Subcutaneous; Inside body cavities, mesentery and visceral fat

Mansonella ozzzardi

Skin snips

Onchocerca volvulus

blood

Mansonella perstans Mansonella streptocerca Mansonella ozzzardi

Simulium damnosum (black flies; buffalo fly)

Onchocerca volvulus

Culicoides spp (night/biting midges)

Mansonella perstans Mansonella streptocerca Mansonella ozzzardi

Found in Africa

Mansonella perstans Mansonella streptocerca

Non-periodic

Onchocerca volvulus Mansonella perstans Mansonella streptocerca Mansonella ozzzardi

East, Central & West Africa; Guatemala, Mexico, Colombia & Venezuela

Onchocerca volvulus

Tropical Africa & South America

Mansonella perstans

Tropical Africa

Mansonella streptocerca

Tropical America

Mansonella ozzzardi

➢ nodular and erythematous lesions

O. volvulus

➢ eosinophilia and urticaria (allergy)

➢ Ocular involvement Photophobia lacrimation blindness

O. volvulus

DH:

Man

IS:

3rd stage larva

IP:

10-12 months

Diagnostic method:

skin snips

➢ DEC (diethyl carbamazine)

Onchocerca volvulus

➢ Destruction of microfilaria produces extreme allergic reaction

Onchocerca volvulus

➢ vector control

Onchocerca volvulus

➢ treatment of infected individuals

Onchocerca volvulus

➢ avoidance of black fly

Onchocerca volvulus

250-300 µm

Onchocerca volvulus

150-200 µm

Mansonella ozzzardi M. perstans

180-240 µm

Mansonella streptocerca

150-200 µm

Mansonella ozzzardi M. perstans

8 µm

Onchocerca volvulus

4 µm

Mansonella perstans Mansonella ozzzardi

5 µm

Mansonella streptocerca

Sheath absent

Onchocerca volvulus Mansonella perstans Mansonella streptocerca Mansonella ozzzardi

Regular slightly twisted

Onchocerca volvulus

Regular often forms loops

Mansonella perstans

Tail usually curved

Mansonella streptocerca

Regular slightly twisted

O. volvulus Mansonella ozzzardi

Cephalic space Large and bulbous

Onchocerca volvulus

Cephalic space Large

Mansonella perstans Mansonella streptocerca Mansonella ozzzardi

Coarse mostly separated

Onchocerca volvulus

Medium sized tend to overlap

Mansonella perstans

Fine mostly separated

Mansonella streptocerca M. ozzari

Fine mostly separated

Mansonella streptocerca M. ozzari

No nuclei pointed tip

Onchocerca volvulus M. ozzardi

Nuclei present rounded/blunt tip

Mansonella perstans

Nuclei present curved tip

Mansonella streptocerca

No nuclei pointed tip

O. volvulus Mansonella ozzzardi

Non periodic

Onchocerca volvulus Mansonella perstans Mansonella streptocerca Mansonella ozzzardi

Dracunculus medinensis Discoverers

Linnaeus and Gallandant

Guinea worm; fiery serpent of the Israelites; Medina worm, serpent worm or dragon worm

Dracunculus medinensis

Infective stage L3 larva (filariform)

Dracunculus medinensis

Main Habitat cutaneous and subcutaneous tissue

Dracunculus medinensis

Life span 12-18 months

Dracunculus medinensis

✓ Females: 50-120 cm long by 0.7 -1.7 mm in diameter

Dracunculus medinensis

✓ Males: 12-29 by 0.4 mm

Dracunculus medinensis

Dracunculiasis /Dracontiasis/Dracunculosis

Dracunculus medinensis

North, West and Central Africa, southwestern Asia, the West Indies and northeastern South America

Dracunculus medinensis

➢ local blister

Dracunculus medinensis

➢ outline of the worm under the skin may be revealed by reflected light

Dracunculus medinensis

➢ Dead calcified worms may be located by Roentgen-ray examination

Dracunculus medinensis

➢ Visual observation of painful skin blister- outline of worm under the skin is revealed by reflected light; emerging worm

Dracunculus medinensis

➢ Larvae release may be induced when cold water is applied

Dracunculus medinensis

➢ Calcified worm may be located by x-ray

Dracunculus medinensis

➢ Worm lies in a subcutaneous tunnel (marked with induration and edema)

Dracunculus medinensis

➢ Worm liberates toxin o inflammatory reaction: sterile blister with serous exudation

Dracunculus medinensis

➢ Contamination of the blister: abscesses, cellulitis, extensive ulceration and necrosis

Dracunculus medinensis

➢ If worms fail to reach the skin, it dies and either disintegrates or calcifies

Dracunculus medinensis

➢ Mesenteric tissues- it causes pseudoperitoneal syndromes and allergic manifestations.

Dracunculus medinensis

➢ Superficial tissues- the worm liberates a toxic substance that produces local inflammatory reactions; blisters appear at any location and rupture of blister favors the escape of larva.

Dracunculus medinensis

➢ Contamination of ruptured blister causes secondary bacterial infection such as abscesses, cellulitis, extensive ulceration and necrosis

Dracunculus medinensis

➢ Protection of drinking water (Cyclops and larvae)

Dracunculus medinensis

➢ Infected individuals must not be allowed to bathe or wade in water used for drinking purposes

Dracunculus medinensis

➢ Refrain from drinking from suspected water source

Dracunculus medinensis

➢ Boiling of water.

Dracunculus medinensis

Provision of piped water or wells

Dracunculus medinensis

➢extraction of the guinea worm

Dracunculus medinensis

➢multiple surgical incisions

Dracunculus medinensis

➢Metronidazole

Dracunculus medinensis

➢ Mebendazole, niridazole, thiabendazole

Dracunculus medinensis

➢ Surgical removal of the worm or slow withdrawal from blister by gentle traction and rolling the protruded portion on a stick (few cm per day)

Dracunculus medinensis

➢ Aspirin for pain and prevent secondary infection

Dracunculus medinensis

Length: : 2 to 3 centimeters long and are rust-colored

GNATHOSTOMA SPECIE

four rows of hooklets extruding from the surface of the cephalic bulb

GNATHOSTOMA SPECIE

Tiny, cuticular spines run along the length of their bodies

GNATHOSTOMA SPECIE

Two types of papillae extend from the worm--a cervical papilla off the main body and two labial papillae on the cephalic bulb

GNATHOSTOMA SPECIE

Four sac-like openings in the cephalic bulb

GNATHOSTOMA SPECIE

ovular with a mucus plug at one end

GNATHOSTOMA SPECIE

approximately 40 micrometers to 70 micrometers

GNATHOSTOMA SPECIE

may cause a VLM like syndrome (Southeast Asia)

GNATHOSTOMA SPECIE

The larvae may migrate through subcutaneous tissues, causing transient swelling, and to deeper tissues, eventually invading the CNS

GNATHOSTOMA SPECIE

resemble those of hookworms (78-98 µm by 40-50 µm)

7. TRICHOSTRONGYLUS SPP

slightly tapered at one end

7. TRICHOSTRONGYLUS SPP

Adult females lay eggs in the large intestine of the host that are shed with the feces.

7. TRICHOSTRONGYLUS SPP

Once in the environment the eggs release the L1-larvae that complete development to infective L3-larvae in about 5 days by suitable weather (hot and humid), significantly longer by cold weather.

7. TRICHOSTRONGYLUS SPP

These infective larvae can survive in the environment and remain infective for up to 6 months.

7. TRICHOSTRONGYLUS SPP

small intestines: eggs – larvae-ingestion by DF

7. TRICHOSTRONGYLUS SPP

• 1st IH: copepods • 2nd IH: fish and amphibians

6. GNATHOSTOMA SPECIE

eating undercooked or raw freshwater fish, eels, frogs, birds, and reptiles

GNATHOSTOMA SPECIE

contaminated water

GNATHOSTOMA SPECIE

In rare instances, larvae can directly penetrate the skin of individuals who are exposed to contaminated food sources or freshwater.

GNATHOSTOMA SPECIE

Gnathostomiasis

(Gnathostoma spinigerum)

food-borne parasitic infection that results from the human ingestion of the thirdstage larvae

Gnathostomiasis

- Choko-Fushu Tua chid or chokofishi (Japan)

Gnathostomiasis

- consular disease (Nanjing)

Gnathostomiasis

- Shanghai rheumatism

Gnathostomiasis

- Tau-cheed (Thailand)

Gnathostomiasis

- Woodbury bug (Australia)

Gnathostomiasis

- Yangtze River edema

Gnathostomiasis

- migratory swellings under the skin

GNATHOSTOMA SPECIE

- increased levels of eosinophils in the blood

GNATHOSTOMA SPECIE

- Rarely, the parasite can enter other tissues such as the liver, and the eye

GNATHOSTOMA SPECIE

- vision loss or blindness

GNATHOSTOMA SPECIE

- It can also affect the nerves, spinal cord, or brain, resulting in nerve pain, paralysis, coma and death.

GNATHOSTOMA SPECIE

light & asymptomatic

TRICHOSTRONGYLUS SPP

heavy infection may produce abdominal pain and diarrhea, usually with eosinophilia

TRICHOSTRONGYLUS SPP

- worms damage the lining of the small intestine or the stomach