BLOOD AND TISSUE NEMATODES Flashcards
BLOOD AND TISSUE NEMATODES aka
Filarial worms
• Infective stage to man:
filariform/filiform/3rd stage microfilariae
• Infective stage to vector:
microfilariae (adult worm lays eggs in the circulation; ingested by mosquito)
• Pathogenic stage to man:
adult worm (pain is felt; disease occurrence)
Diagnostic stages
Microfilariae: blood
Adult larvae: lymphatics
MOT
Arthropod transmitted/mosquito-borne parasites
- threadlike, creamy, white, varies in length (2-50 cm)
- Adult
- snake-like with a column of cells in the anterior to the posterior portion (develops in the vector)
- larval stage
-pre-larval stage, embryos produced by filarial worms usually found in the blood or tissues of patients with filariasis, highly motile and threadlike
- Microfilaria
Location of Microfilariae in man:
peripheral blood and lymph spaces of the skin
a thin, translucent egg shell remnant covering the body of the microfilaria and past the head and tail
Sheath
SHEATHED Microfilariae
- Wuchereria bancrofti
- Brugia malayi
- Loa loa
UNSHEATHED Microfilariae
- Onchocerca volvulus
- Dipetalonema perstans/Mansonella perstans
- Dipetalonema streptocerca/Mansonella streptocerca
- Mansonella ozzardi
rhythmical appearance of microfilariae in the peripheral blood; maximum biting activity of the vector/active/helps in the PBS
Periodicity
Periodicity Types:
- Periodic
- Subperiodic
- Non-periodic
- Periodic:
➢ Nocturnal –
➢ Diurnal –
10pm to 2am
10am to 2pm
- Subperiodic:
➢ Nocturnally –
➢ Diurnally –
peak count during night time
peak count during day time
- Non-periodic:
during night time and day time
Disease caused by
Lymphatic Filariasis
: swelling in the scrotum that occurs when fluid collects in the thin sheath surrounding a testicle.
a) Hydrocele
: swelling that generally occurs in one of the arms or legs
b) Lymphedema/Lymphangitis
: condition characterized by gross enlargement of an area of the body, especially the limbs
c) Elephantiasis
: rare condition in which lymphatic fluid leaks into the kidneys and turns the urine milky white
d) Chyluria
✓ 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)
Laboratory Diagnosis for Filariae
- Microscopic Examination
- Capillary tube method
- Immunoassay
- 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
- Capillary tube method
➢ Antigen detection- circulating filarial antigens
- Immunoassay
➢ Molecular diagnosis using PCR- differentiation of filarial species and stage
- Immunoassay
➢ Ultrasonography- demonstrate live worms in the lymphatics
- Identification of adult worms
➢ Contrast lymphangiography & lymphscintigraphy using radiolabeled albumin or dextran
- Identification of adult worms
➢ Tissue samples collected during nodulectomies (onchocerciasis)
- Identification of adult worms
➢ Subcutaneous biopsies or worm removal from the eye (loiasis)
- Identification of adult worms
Prevention
Abaca workers-wear [?]
Use of mosquito repellants and/or mosquito nets; vector control (?)
long sleeves shirts
insecticides
Treatment
- DEC (Diethylcarbamazine)/Hatrazan
- 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)
- TRICHOSTRONGYLUS SPP
slightly tapered at one end
- TRICHOSTRONGYLUS SPP
Adult females lay eggs in the large intestine of the host that are shed with the feces.
- 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.
- TRICHOSTRONGYLUS SPP
These infective larvae can survive in the environment and remain infective for up to 6 months.
- TRICHOSTRONGYLUS SPP
small intestines: eggs – larvae-ingestion by DF
- TRICHOSTRONGYLUS SPP
• 1st IH: copepods
• 2nd IH: fish and amphibians
- 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
Trichostrongylosis or Trichostrongyliasis
- enteritis, gastritis, and sometimes anemia
Trichostrongylosis or Trichostrongyliasis
- Typical signs are diarrhea (mucous and/or hemorrhagic) or constipation
Trichostrongylosis or Trichostrongyliasis
- general weakness and wasting
Trichostrongylosis or Trichostrongyliasis
- loss of appetite
Trichostrongylosis or Trichostrongyliasis
- reduced weight gains or even weight loss, etc. x
Trichostrongylosis or Trichostrongyliasis
- Acute severe infections in young animals may be fatal
Trichostrongylosis or Trichostrongyliasis
• Zoonotic infection (herbivores)
TRICHOSTRONGYLUS
• Human infection:
T. colubriformis, T. orientalis, T. axei, T. brevi
: Infects poultry and other birds worldwide
Trichostrongylus tenuis
.: - The stomach hairworm
Trichostrongylus axei
- Infects cattle, sheep, goats, pigs and horses and many wild mammals.
Trichostrongylus axei
- Found worldwide
Trichostrongylus axei
- Bankrupt worms, black scours worms:
Trichostrongylus colubriformis
- Infects cattle, sheep, goats, pigs and horses and many wild mammals.
Trichostrongylus colubriformis
- Found worldwide
Trichostrongylus colubriformis
Other less frequent species are
Trichostrongylus probolurus and Trichostrongylus vitrinu
migratory lesions
- GNATHOSTOMA SPECIE
eating raw fish
- GNATHOSTOMA SPECIE
detection of characteristic eggs in the feces
- TRICHOSTRONGYLUS SPP
determination of the species requires post mortem examination of adult worms after necropsy
- TRICHOSTRONGYLUS SPP
