BLOOD AND TISSUE NEMATODES Flashcards
vector-borne filarial nematode genus associated w human infections
Mansonella spp.
three species of Mansonella
M. ozzardi
M. perstans
M. streptocera
Mansonella spp.: primary vectors
biting midges (Midge fly) of genus Culicoides
Mansonella spp.: a New World species w a patchy distribution; endemic to Central America
M. ozzardi
Mansonella spp.: an Old World species that occurs in tropical regions of West and Central Africa
M. streptocerca
Mansonella spp.: endemic throughout West, East, and Central Africa
Mansonella perstans
M. perstans was likely introduced where?
neotropical regions of Central and South America
Mansonella spp.: symptomatic or asymptomatic infection?
asymptomatic
M. perstans and M. ozzardi diagnosed by?
finding microfilariae cicrulating in BLOOD
M. streptocerca is usually diagnosed by?
finding microfilariea in SKIN SNIPS
standard treatment for mansonellosis
none
combination therapy for M. perstans mcirofilaremia?
diethylcarbamazine + mebendazole
diagnostic stage for filariasis
microfilaria
Filariasis: infective stage to the midge
microfilariae
unique characteristic of M. perstans
has blunt rounded tail w nucleus extending to the tip; unsheated
difference of M. perstans from Loa Loa
Loa Loa is SHEATED (clear ext. found in the body of the mcirofilaria)
unique characteristic of M. streptocerca
has a hook-tail
Mansonella spp.: infective stage to humans
L3 larvae
mode of transmission from midge to humans
L3 enters through BITE WOUND of the midge fly
vectors for M. ozzardi
Arthropod
- black fly of genus Simulium
- midge of genus Culicoides
unique characteristic of M. ozzardi
body nuclei do NOT extend to tip of tail; long, thin pointed tail
drug of choice for filariasis
DEC (diethylcarbamazine)
treatment for M. ozzardi
ivermectin
treatment for M. streptocerca
DEC
Ivermectin
treatment for M. perstans
DEC + mebendazole (most widely used)
Mebendazole
Doxycycline
common name for Dracunculus medinensis
Guinea worm
Medina worm
Fiery serpent
Dracunculus medinensis: disease
dracunculiasis
Dracunculus medinensis: parasite is freq. found in?
subcutaneous tissues
muscles of human, dog, cattles & horses
Dracunculus medinensis: disease causes what?
cutaneous nodules
subsequent ulcers
Dracunculus medinensis: larvae difference of survival duration between clean water and muddy water
Clean water: 6 days
Muddy water: 2-3 weeks
Dracunculus medinensis: infective stage
L3 larva
Dracunculus medinensis: definitive host
humans, dogs, horses
Dracunculus medinensis: intermediate host
cyclops, copepods
Dracunculus medinensis: mode of transmission to humans
human drinks unfiltered/contaminated water containing copepods w L3 larvae
Dracunculus medinensis: treatment
- removal of worm
- filtering water sources
- avoid contact w contaminated water
Dracunculus medinensis: drug of choice
none
Dracunculus medinensis: best treatment to prevent infection
filtering water sources
common name of Trichinella spiralis
Trichina worm
Pork worm
Trichinella spiralis: diseases
- trichinosis
- trichiniasis
- trichinellosis
Trichinella spiralis: cloaca is found at the ? (male worm)
caudal end
Trichinella spiralis: functions to clasp the female during female during copulation
2 conspicuous conical papillae
Trichinella spiralis: spicule
none
Trichinella spiralis: anterior or posterior ? curved ventrad (male worm)
posterior end
Trichinella spiralis: female worm has how many uterus?
single uterus containing larvae
Trichinella spiralis: vulva opens at teh ?
anterior fifth of the body
Trichinella spiralis: ANTERIOR end of encysted larva contains ?
spear-like burrowing tip
Trichinella spiralis: infective stage
encysted larva
Trichinella spiralis: definitive host
swines
man (accidental and definitive host)
Trichinella spiralis: diagnostic stage
encysted larva
Trichinella spiralis: functions to encyst in the muscle area
spear-like burrowing tip
Trichinella spiralis: definitive diagnosis
muscle biopsy
Trichinella spiralis: sylvatic cycle
from bears
Trichinella spiralis: domestic cycle
from pigs
Trichinella spiralis: mode of infection to humans
ingestion of undercooked meat which contains the encysted larva
Trichinella spiralis: dead-end host
humans
Trichinella spiralis: diagnosis
- muscle biopsy
- Bentonite Flocculation Test
Trichinella spiralis: diagnosis that has higher sensitivity; detects antibody
Bentonite Flocculation Test
Trichinella spiralis: clinical disease
- destruction of muscle fiber
- eosinophilia
- may have myocardial involvement
Trichinella spiralis prevention and control: cook meat properly at what temp
77C or 170F
Trichinella spiralis prevention and control: storage
-15C for 20 days
-30C for 6 days
Trichinella spiralis: treatment
thiabendazole
mebendazole
common name of Angiostrongylus cantonensis
rat lungworm
Angiostrongylus cantonensis: originated in
domestic rats in Canton, China
Angiostrongylus cantonensis: normally lives in?
lungs of rats
Angiostrongylus cantonensis: cause ? in man
eosinophilic meningoencephalitis
Angiostrongylus cantonensis: disease
Angiostrongyliasis
Eosinophilic meningoencephalitis
Angiostrongylus cantonensis: barber’s pole pattern
female
Angiostrongylus cantonensis: have a well-developed CAUDAL BURSA (kidney-shaped, single-lobed)
male
Angiostrongylus cantonensis: infective stage
L3 larvae
Angiostrongylus cantonensis: definitive host
rats
Angiostrongylus cantonensis: incidental host
humans
Angiostrongylus cantonensis: intermediate host
snails (Achatina fulica)
Angiostrongylus cantonensis: mode of infection to humans
accidential ingestion of gastropod or larvae
Angiostrongylus cantonensis: presumptive diagnosis
travel history
exposure
Angiostrongylus cantonensis: diagnosis
- relatively difficult
- presumptive diagnosis (travel history & exposure)
- CSF (10% eosinophilia in proportion to the WBC
- CT scan
- ELISA
Angiostrongylus cantonensis: recommended anti helminthic treatment
none
Angiostrongylus cantonensis: management
- symptomatic treatment w analgesics
- freq. removal of about 10ml spinal fluid at intervals relieves headaches (invasive)
Angiostrongylus cantonensis: treatmeat effective in experimental animals
Albendazole
Mebendazole
Ivermectin
Thiabendazole
Anisakis spp.: disease
Anisakiasis
Anisakidosis
nematode parasites of whales, dolphins, porpoises, walruses, seals, sea lions and other deep marine mammals
Anisakids
Anisakis spp.: referrred to as Type 1 larvae
3rd stage larva
Anisakis spp.: milky white; long stomach, blunt tail w mucron
3rd stage larva
Anisakis spp.: transmission to humans via?
raw or undercooked seafood consumption
Anisakis spp.: infective stage
L3 larvae
Anisakis spp.: definitive host
marine mammal
Anisakis spp.: intermediate host
crustaceans
Anisakis spp.: paratenic host
fish or cephalopod
Anisakis spp.: accidental host
humans
Anisakis spp.: pathology
- gastric pathology
- intestinal pathology
- allergic reactions
Anisakis spp.: diagnosis of Anisakiasis can be made by
gastroscopic examination during which the larvae can be removed
Anisakis spp.: Diagnosis
- recent histroy of eating RAW or improperly cooked fish or squid
- gastroscopic/endoscopic examination
- serological test (ELISA, RAST)
Anisakis spp.: serological test - ELISA stands for
enzyme-linked immunosorbent assay
Anisakis spp.: serological test - RAST stands for
radioallergosorbent assay
Anisakis spp.: treatment
- mechanically remove the larva using endoscopic forceps (main approach)
- corticosteroids
- albendazole