L15: Lung and Intestinal Flukes Flashcards
What is P. werstermani
def host: animals and humans
int host: snails
2nd int: crab/crayfish
lung flukes
causes lung fluke disease or paragonimiasis
Life Cycle of Paragonimus westermani
Paired adult P. westermani usually reside in the infected hosts lungs.
Produced eggs are coughed up and excreted unembryonated in the
sputum. Some coughed up eggs are swallowed with sputum and
passed with feces.
2. In the external environment, the eggs become embryonated
3. The miracidia hatch and seek the first intermediate host (a snail) and
penetrates its soft tissues
4. Inside the snail, miracidia develop to sporocysts (4a), then rediae
(4b), which give rise to many cercariae (4c). Cercariae emerge from
the snail.
5. The cercariae invade the second intermediate host, a crustacean
(crab or crayfish). Here, the cercariae encyst and become
metacercariae. This is the infective stage for the mammalian host
6. Human infection with P. westermani occurs by eating inadequately
cooked or pickled crab or crayfish that harbor metacercariae
7. The metacercariae excyst in the duodenum, penetrate through the
intestinal wall into the peritoneal cavity, then through the abdominal
wall and diaphragm into the lungs. Here, they become encapsulated
and develop into adults. Time from infection to oviposition is 65 to
90 days. Infections persist for the life-span of the adult worm which
may be 6-20 years in humans
Juvenile worms can also reach other organs and tissues such
as the brain and striated muscles, respectively. When this
takes place, completion of the life cycle is not achieved
Why is this so?
Generally Clinical manifestations of paragonimiasis
asymptomatics
heavy infection = pulmonary issues, eggs and worm become encapisaule and ulcerate
often thought to be TB
What are the phases of Paragonimiasis
actute: poop, abdomindal, fever, hives, breathing issues
chronic: cough, chest pain, night sweat, chest radiogrpahic weirdness, discoloured spetum
Extrapulmonary/ectopic
*go to intenstine and liver, pain, vomit
*brain infected => headache
*death
Epidemiology is Paragonimiasis
P. westermani in Asia
P. kellicotti is north america
people who handle food/juice
Diagnosis: clinical history of consumption, Xray/CT, chest MRI, eggs in spetum
Treatment: praziquantal
What is Fasciolopsis buski
- largest digenitc tramtode
*fiant intesntial fluke
def host: humans, dogs, pigs
pigs being most important
int host: snails
causes fasciolopsiasis
Life Cycle
Immature eggs are discharged into the intestine and stool
2. Eggs become embryonated in water
3. The miracidia hatch from the eggs
4. These invade a suitable snail intermediate host. In the snail,
the parasite undergoes several developmental stages –
sporocysts (4a), rediae (4b), and cercariae (4c)
5. The cercariae are released from the snail
6. Cercariae then encyst as metacercariae on aquatic plants,
most commonly water chestnut, water caltrop, water
bamboo and lotus. The mammalian hosts become infected by
ingesting metacercariae on the aquatic plants when they eat
contaminated raw plants or peel the outer covering off edible
plants with their teeth
7. After ingestion, the metacercariae excyst in the duodenum
and attach to the intestinal wall.
8. There they develop into adult flukes in approximately 3
months, attached to the intestinal wall of the mammalian
hosts (human and pigs). Adults have a life span of about one
year
Clinical Presentation of Fasciolopsiasis
for light asymptomatic
for heavy: words feed on intenstinal and mucosa, inflammation, uncleration and absses => intestinal obstruction
you poop, puke, pain after eating u feel better => cause they eat there
toxins cause bad reactions
fatal
Epidemiology of Fasciolopsiasis
- Asia China, Taiwan, Lao, Viet…
consume pigs/freshwater
common to fertilize ponds in which plants are grown with untreated
human or swine excrement, thereby contaminating the plants
*kids
Diagnosis: clincial symptoms in endemic areas, eggs in poop, vomit or poop
Treatment of Fascio
Prazi
