Helminths: Tremotoda (flukes) and Cestoda
(tapeworms)—mm and a nervous system
Eosinophilia
-eosinophils > 5%
-tissue invasion with larvae
-Th2 response: Il4, Il5, Il13
cestoda—tapeworms
-no free living
-no separate sexes
-segmented
-tegument
-no cavity
-no GI tract
-ribbon or band shaped
scolex- the “head”
rostellum
hooks
4 suckers
-strobila—string of proglottids (segments)
d. latum
taneia saginata- 4 suckers
taenia solium -suckers w. hooks
-ADULTS in intestine—NO clinical effect
PATHO- damage caused by larve penetrating through intestinal wall
DIAG- eggs or proglottids in feces
Flukes
-no free living
-tegument
-no body cavity
-GI tract with no anus
Diphyllobothrium latum-
intestinal infection
diphyllobothrium latum
-fish tapeworm
sx



epigastric pain
nausea
vomiting
occasional intestinal obstruction



diarrhea
abdominal pain
megaloblastic anemia
o impairs absorption of B12
intermediate hosts: water fleas fish
def host- human, fish eating mammals
transmit- eat fish (larvae)
-passed in human feces
geo: north america, europe, soviet union, asia, chile
ADULTS in intestine—NO clinical effect
PATHO- damage caused by larve penetrating through intestinal wall
DIAG- eggs or proglottids in feces

Operculated/flat eggs with knob on the bottom of the shell


Niclosamide
Prazyquantel
Trt
dipylidium caninum
11/4/2010 12:47:00 AM
Double pore tape worm
definitive host: pet owners and children
-cats and dogs
intermediate host: flea (larvae)
Tramsit: ingestion of fleas with larvae
-passed in human and pet feces
-emerge from perianal area
sx

abdominal discomfort


anal puritis
diarrhea
geo: world wide
DIAG- eggs or proglottids in feces
Trt: niclosamide
-prazyquantel
-ADULTS in intestine—NO clinical effect
PATHO- damage caused by larve penetrating through intestinal wall
Hymenolepsis nana
Hymenolepsis diminuta
11/4/2010 12:47:00 AM
Definitive host: humans and rodents
-dimunata
-nana
Intermediate host: fleas/beatles and humans
-nana
Transmit:
-eat fleas with larvae definitive human host
-eat feces with eggs  intermediate human host
-resevoir host: dogs, rodents
sx
-abdominal discomfort
-diarrhea
-abdominal pain
-restlessness
-irritability
-restless sleep
-anal purtitis
-nasal puritits
geo
hymenolepsis nana- worldwide

Temperature regions: children and institutionalized groups
Hymenolepsis diminuta
 Southeast USA
DIAG- eggs in feces
Trt- prazyquantel
Taenia saginata (beef)
11/4/2010 12:47:00 AM
Definitive: human only
Intermediate: beef larvae in muscle
Cattle – eat grass with human feces
transmit:
humans eat larvae in beef meat
SX

abdominal discomfort**
o passage of proglottids through the intestinal tract
 appedicitis or cholangitis from migrating proglottid
geo: worldwide
diag: eggs in feces
adults are distinguishable
 beef – 4 suckers

proglottids- MORE uterine branches
trt- prazyquantel
taenia solium – intestinal and tissue infection
-pork/ham/bacon—SO SALTY! Like sodium
definitive host: human only
intermediate: pigs and HUMANS
transmit:
 eat pig meat with larvae
 eat our human feces
(pigs and humans)
geo: worldwide
-prevalent in poorer communities
SX

abdominal discomfort**
o passage of proglottids through the intestinal tract
 appedicitis or cholangitis from migrating proglottid
-less frequently symptomatic than T saginata
diag: eggs in feces
adults are distinguishable
 pork– 4 suckers, hooks
 proglottids- thicker and less uterine branches in proglottids
trt: prozyquantel
tissue infection!
Trasmit: eat eggs in human feces
Sx-
-cysts = nodules
 calcified nodules in brain and mm


subcutaneous nodules (MC)
calcified nodules in mm (MC)



ocular
cardiac
spinal lesions

brain
o
o
o
o
o
neurocysticercosis
seizures
mental disturbances
focal neurologic deficits
space occupying intracerebral lesions
Geo: california
Diag:




antibody detect
o immunoblot (western blot)
biopsy
CT scan
Eosinophilia



Surgery : removal of the cysts
Albendazole or mebendazole + steroids
Anticonvulsant drugs when needed
Trt
If asymptomatic- will subside 2-5 yrs
 Do not treat
echinococcus granulosus
echinococcus multilocularis
11/4/2010 12:47:00 AM
Hyatid worm
[HUMANS not the defininitive HOST]
definitive host:
dogs
intermediate host:
human and
livestock
transmit: eat dog poop – feces

vegetables and fruits with feces on
it


LATENCY ~ silence for years
[Cysts in organs]

Hepatic- abdominal pain, mass in
sx
hepatic area, biliary duct
obstruction

Pulmonary- chest pain, cough, hemoptysis

CYST RUPTURE- fever, hives, eosinophilia, anaphylactic shock,
cyst dissemination
Geo- worldwide
sheep viscer)
(sheep farms, grazing lands where dogs run free and eat
-e multilocularis in the Northern hemisphere
 definitive host: fox, intermediate host: rodent
diag
-antibody detection
-ultrasound or other imaging and serology
-seronegative and biopsy
treat

surgery
o danger: ruptured cyst
 release of antigen to cause shock



release of protoscolices new cysts
albendazole or mebendazole
o to keep cyst from reoccurring
dogs - prazy
Flukes
11/4/2010 12:47:00 AM
Flukes
-no free living
-tegument
-no body cavity
-GI tract with no anus
fluke life style
water
1) eggs in feces/urine/sputum hatch in water
 motile micracidum
snails (obligate host)
2) motile micracidum infect snails
 sporocyst/ redia (amplification)
released from snail  motile cercaria
water
3) motile cercaria ---INFECTIVE
human  Adult
(schisto water adult)
OR
vegetation or secondary intermediate host meta cercaria ----INFECTIVE
(lung flukeshellfish human)
(liver fluke vegetation human)
 human adult
Shistosomiasis—BLOOD FLUKES
Schistosome life cycle
 penetrates skin
 loses tail and becomes a shistosomulae
 circulation  portal blood  liver  matures into adult/ mates
 lay eggs in mesenteric vein/ bladder veins
s. mansoni mesenteric veins
s. japonicum mesenteric veins
s. haematobium veins of bladder
 NOT in the US
- Separate sexes
in Human
-adults life 20-30 years
-eggs migrate into intestinal lumen or bladder (feces/urine)
 produce proteases for tissue migration
-pathology: autoimmune response to eggs trying to get out of host
 50% of eggs die within host and also trigger IS
 eggs leave thru feces, urine, sputum in water
transmission: water born motile cercaria
-DIRECT skin penetration (via HA)
-tegement takes up host components of RBC antigens, HLA, Ig
 cercaria schistosomulum (in human ~2d)

after enters skin searches for blood vessels and antigen coating


immature schistosomes feed on plasma
migrates through vessels of lungs to liver where ADULTS MATE
Patho
-release halo of NO, PG, LT to vasodilate and so it can move through vv
-inhibits phagocytosis
-molecular mimicry
-covers themselves in ABO Ag/ RBC membrane
Eggs that die in tissues
-egg induced granuloma
Liver migration and drug
 Noxious stimuli  out of vasculature LIVER MIGRATION and
surrounds itself with cytochrome p450 so liver detoxifies the drug
-they mate for years
SX
-live for 20 years
-eggs produced for over 10 years
-see clinical symptoms years later when eggs have been built up and died
AND also by eggs that are trying to get out
Schistosoma mansoni and S. japonicum

liver fibrosis
o
symmer’s clay pipestem fibrosis- fibrosis of
all large vv of liver

portal hypertension with collateral circulatoin

ascities

esophageal varices

vomiting blood
shistosoma haematobium (bladder fluke)
 hematuria in early disease
 fibrosis of bladder
 obstructive uropathy (granulomas)
 renal failure and hydronephrosis
 bladder carcinoma
-egg in urine/feces
Diag
Eggs in feces or urine
Immunodiagnosis: ELISA, IFAT, RIA, IHA (indirect hemoagglutination)
spike on side
spine on end
trt
-praziquantel (PZQ) and oxaminiquine
Vaccine
 target the schistosomulum
 enzymes to penetrate the skin
-low worm load may give minimal disease
-concomitant immunity- worms caused TH2 response were supressing
pathology of malarial infection
 maybe use to suppress crohn’s disease?
-macrophages, eosinophils, neutrophils all involved **
-cercarial dermatitis
-speices in ducks that do not use ppl as
host
-fail to form functional schistosomulum and
die
-inflammatory reaction in skin

small red spots in 30 min

inc in size 24-30 hr

resolves 4-7d
Lung Fluke –paragonimus westermani
-cercaria releasted from snails raw undercooked shell fish, crap, shrimp
(metacecarae)  humans
 tissue invasion  lung cavities (adults mature)
-eggs in sputum may be swallowed and then shed through feces
geo: korea, japan, taiwan, central china, phillipines
SX:
Acute (invasion and migration):
-diarrhea (shed through feces)
-abdominal pain
-fever, cough
-pulmonary abnormalities
-eosinophilia (DIAGNOSTIC)**
[acute liver: : diarrhea, abdominal pain, fever, vomiting, enlarged liver]
Chronic:
-pulmonary manifestations
 cough, discolored sputum--expectorated clusters of reddish brown
eggs, not blood
-radiographic abnormalities (pseudeotubercules)
-may persist for 20 yrs
 patho related to inflam response and how many flukes
Diagnosis: eggs in stool / sputum (not present until 2-3 months after
infection)
-persist for 20 years
Treatment: Praziquantel
Liver Fluke- fasciola
Transmission: consumption of raw/undercooked water vegetables; pig
feces
Symptoms:
 Acute: diarrhea, abdominal pain, fever, vomiting, enlarged liver
 Chronic: intermittent blockage of the bile duct and inflammation
o
MOST DIAGNOSTIC
Diagnosis: eggs in stool
Treatment: Praziquantel