Gnathostoma spinigerum Filarial worms · Gnathostoma spinigerum Filarial worms. Objective ......
Transcript of Gnathostoma spinigerum Filarial worms · Gnathostoma spinigerum Filarial worms. Objective ......
Prof. Kabkaew Sukontason Dept. Parasitology, Fac. Medicine
Gnathostoma spinigerum
Filarial worms
Objective
Gnathostoma spinigerum
Filarial worms
- Wuchereria bancrofti - Brugia malayi
- Morphology
- Life cycle & Route of infection
- Clinical manifestation
- Treatment - Prevention
Gnathostoma: Round worm (nematode)
Family : Gnathostomatidae
Thailand: 5 species
G. spinigerum
G. hispidum
G. doloresi
G. malaysiae
G. vietnamicum
พยาธิตัวจี๊ด ~23 species
M
F
spicule (for mating)
- stout body
- head bulb
- 8-11 rows of cephalic spines help worm lodge in host’s tissue
- Female: 1.3-5.5 cm
- Male: 1.6-4 cm (+ 2 spicules)
Morphology of adult
head bulb
cephalic spines
Life Cycle: complex
eL3
aL3
accidental or paratenic host
L2
DH: dog, cat, tiger
wild mammals Habitat: stomach (tumor)
2nd IH: freshwater fish
1st IH: cyclops
PH
PH
PH
PH
PH: fish, amphibians,
reptiles, birds, etc
egg
- oval shape - a polar plug at one end
L2
eL3
When newly hatched, ensheathed L2 were ingested
by cyclop.
Moult to EL3 in the body cavity of cyclop.
eL3 in Cyclops
~0.5 mm
Morphology of L3 - early L3 (0.5 mm) - advanced L3 (3-4 mm)
- head bulb
- 4 rows of cephalic spines
- Incomplete reproductive organs
eL3 aL3
Tumor in stomach wall
become adult after 4-6 mo.
DH: stomach --> peritoneal cavity --> liver --> stomach (tumor)
Human (accidental host): have adult (rare), but cannot return to stomach (+tumor)
Route of infection
Ingestion of raw, undercooked animals (+ L3): 2nd IH, PH..Somfak, Pla-ra (Thailand: eel, snake-headed fish, undercooked chicken)
Skin penetration: during food preparation
Congenital transmission: 3d, 7 d, 1 mo
Swallowing water (+ infected Cyclops)
Wound: use of fresh dead animal (Jpn, China)
(Fresh-water fish foodborne zoonoses)
Fermented fish: ส้มฟัก ปลาร้า
Human: accidental host
- aL3
- immature adult
- mature adult (rare)
Pathology
depend on organ during migration: mechanical injury of organ, tissue produce enz, substances (hemolysin, hyaloronidase, protease)
cause…inflammation, local edema, eosinophil
Clinical manifestation
Human gnathostomiasis
1. Cutaneous gnathostomiasis
intermittent migratory swelling (1 mo. after infection), ~ 1 cm/hr
migrate near body surface may cause creeping eruption inflammatory foci itching
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2. Visceral gnathostomiasis (less common: deep migrate, depend on organ)
CNS: -May present as “myeloencephalitis” or “meningitis”
-Studies in 24 patients with CNS: most common =
“radiculomyelitis” or “radiculomyelitis associated with
encephalitis and subarachnoid hemorrhage”
- may sudden onset of extremely severe radicular pain/
headache paralysis of extremities and/or
cranial nerves
- lung: respiratory symptoms
- eye: pain, visual impairment,
in anterior chamber
- ear, nose, throat: facial swelling
- urogenital
- gastrointestinal tract
- appendix
- etc…..
facial swelling eye swelling
visceral gnathostomiasis: eye
Diagnosis
- definite: parasite identification - parasite migrate out from skin
- dissect out from tissue biopsy (no. nucleus in intestinal cell to identify species)
- clinical manifestation: migratory swelling
1-10 weeks later
- history of ingestion: raw, undercooked animals
- supported by skin test, serology test
G. spinigerum 3-7 nucleus in 1 intestinal cell
Treatment
surgical removal of worm
symptomatic & anti-inflammatory Rx drug: albendazole
- to cure
- to stimulate migration of worm to dermis
-
- ivermectin
Prevention
avoid raw, inadequately cooked animals
prevent larval penetration via skin
avoid drinking water (may +L3)
…boiling water 5 min kill L3...
Filarial worms
Filarial species
- Wuchereria brancrofti
- Brugia malayi
- Loa loa
- Onchocerca volvulus
- Mansonella spp.
- Dirofilaria spp.
Brancroftian filariasis
Malayan filariasis
Habitat: vertebrate host
- lymphatic vessel
- tissue
- body cavity
Disease: Filariasis (Elephantiasis)
Morphology of adult
- long, slender (20-500 mm)
- swollen head, blunt round ends
- white, smooth cuticle - male is shorter than female
M F
Life cycle: complex Definitive host Vertebrate (mammal)
Intermediate host
Invertebrate (blood-sucking insects)
Infective stage
3rd larva
Habitat Adult: lymphatic vessel, tissue, body cavity Microfilaria: blood, tissue
Adult: in tissue produce microfilaria in blood, skin
L1 L2
L3: infective stage
at proboscis
L3
L4
Ad
L3 (infective stage) from proboscis of mosquito
Microfilaria: embryo - thin, long (170-360 mm)
- Bluntly round head, pointed tail - Sheath or no sheath
head
tail
sheath
Morphology of microfilaria
Wuchereria bancrofti Brugia malayi
- long, graceful shape - short, kinking shape
- Giemsa stain: pale sheath - pink sheath
- disperse nuclei - overlapping nuclei
- Short cephalic space (1/1) - long cephalic space (2/1) - No caudal nuclei - 2 caudal nuclei
Wuchereria bancrofti Brugia malayi
Cephalic space
- Short (L/W: 1/1) - long (L/W: 2/1)
Wuchereria bancrofti Brugia malayi
Nuclei
disperse overlap
Wuchereria bancrofti Brugia malayi
caudal nuclei
no 2
Periodic occurrence Continuous occurrence
Microfilarial periodicity
1. Nocturnally periodic
2. Diurnally periodic
1. Nonperiodic
2. Nocturally subperiodic
3. Diurnally subperiodic
In Thailand
W. brancrofti B. malayi
Endemic area
North, west South
Mosquito vector
- Culex
quinquefasciatus
- Anopheles spp.
- Aedes spp.
- Mansonia (Ma. dives)
- Mansonia spp.
- Coquillettidia crassipes
Kanchanaburi
Mae Hong Son
Tak
Narathiwat
Ranong
Ratchaburi
Endemic areas in Thailand
Wuchereria bancrofti (north & west)
Brugia malayi (south)
Mosquito vector
W. Bancrofti B. malayi
Mansonia
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Clinical manifestation Phase W. brancrofti B.
malayi
1. Asymptomatic
2. Inflammatory (acute) - Lymphadenitis (ต่อมน ้าเหลืองอกัเสบ) - Lymphangitis (หลอดน ้าเหลืองอักเสบ) - Orthitis (อัณฑะอักเสบ) - Epididymitis (ท่อเก็บอสุจิอักเสบ) - Elephantoid fever
3. Obstructive (elephantiasis)
- groin region, arms,
leg - hydrocele (ถุงอัณฑะบวมน ้า)
- chyluria
- leg
Pathogenesis
Adult worm (3-10 cm) & lymphatic vessel
Lymphatic endothelium: hyperplasia
Cell infiltration: lymphocyte, eosinophil, histocyte, epitheroid cell,
giant cell & fibroblasts
Fibrosis & lymph blockage
Elephantiasis
skin in the affected area develops a thickened and may become darkened
do not appear until years after infection
Wuchereria brancrofti Brugia malayi
www.oddee.com
www.europeanmedical.info
Diagnosis
I. Clinical diagnosis
- history
- symptom
II. Demonstration of microfilaria - thick blood film
- Knott’s concentration technique
- Millipore filtration
III. Ultrasound (Ultrasonography)
- living adult in lymphatic system
IV. Advanced technique
- ELISA, PCR
Treatment
I. Mass treatment (microfilaria >0.6%)
- once-yearly
- single dose
- 2 drug treatment (removing microfilariae from the blood)
- albendazole (400 mg) + diethylcarbamazine citrate (DEC) (6 mg/kg)
- albendazole (400 mg) + ivermectin (200 mg/kg)
active community-level surveillance
II. Selective treatment (microfilaria < 0.6%)
- DEC (6 mg/kg: 12 days)
III. Supportive treatment (disability person)
- rehabitation
- surgery
Prevention
- Personal protection (avoid mosquito bite)
- Control of mosquito vector
- Mass treatment
Laboratory