Ascaris lumbricoides (description)
largest intestinal nematode of humans
Enterobius vermicularis
Pinworm
largest intestinal nematode of humans
Ascaris lumbricoides
Enterobius vermicularis transmission
person-to-person
bedding/clothing
Ascaris lumbricoides transmission
contaminated soil
Ascaris lumbricoides disease presentation (2)
intestinal due to blockage
pulm: Loeffler’s syndrome
Trichuris trichiura
whipworm
Trichuris trichiura transmission
contaminated soil
Trichuris trichiura disease (4)
asymptomatic
frequent painful passage of stools w/ mucus, water, & blood
rectal prolapse
malabsorption- growth retardation, anemia
Necator americanus & Ancylostoma duodenale
hookworms
hookworm transmission
inadequate disposal of human feces, eggs hatch in soil
hookworms feed on?
blood from intestinal mucosa
hookworm disease? (2)
blood-filled, pruritic lesions at site of larval penetration
anemia
Strongyloides stercoralis
threadworms
Strongyloides stercoralis reproduction
2 multiplication cycles: in host or in soil
strongyloides stercoralis disease (3)
related to larval migration
GI: diarrhea, constipation, malabsorption
Autoinfection
Clonorchis sinensis
Chinese liver fluke
Clonorchis sinensis transmission
ingestion of larvae in improperly prepared fish
Far East
Clonorchis sinensis site of infection in humans
bilary ducts
Taenia solium & Taenia saginata
Tapeworms
Taenia solium infects?
pork
Taenia saginata infects?
beef
only definitive hosts of Taenia
Humans
Taenia transmission
poorly cooked meat
Taenia severe disease presentation?
Cysticercosis- infection travels in blood, can cause seizures & blindness
Diphyllobothrium latum
fish tapeworm
Cysticercosis is associated with what helminth?
Taenia
Diphyllobothrium latum disease
asymptomatic, pernicious anemia
Diphyllobothrium latum reproduction (2)
eggs are released singly, not in proglottids
eggs develop & hatch in water
watery diarrhea, no blood
can be an STI
Giardia
Giardia transmission
feces in water
additional signs of Giardia besides pooping (3)
intestinal pain
anorexia
Vitamin B12 deficiency
bloody diarrhea that can be an STI
amebiasis
Amebiasis causative organism?
Entamoeba histolytica
Entamoeba histolytica trophozoite
ameboid w/ 1 nucleus
Entamoeba histolytica cyst
4 nuclei
end result of acute amoebic colitis
ulcers, RUQ pain
RUQ pain that mimics appendicitis is caused by?
Entamoeba histolytica
Entamoeba histolytica virulence factors
lectin
phospholipase
amebapore
cysteine proteases
Cryptosporidiosis disease
self-limiting diarrheal illness in healthy individuals
Cryptosporidium reproduction (3 things)
doesn’t multiply outside of the host
oocytes are the infectious stage
both asexual & sexual cycles in the host
parasitophorus vacuole
Cryptosporidium
Cryptosporidium transmission (2)
cow –> human
STI
large, round, acid-fast oocyte associated with which infection?
cryptosporidium
causative organism of Cyclosporiasis
Cyclospora cayetanensis
has large, autofluorescent oocyst
Cyclospora
Cyclosporiasis disease associated w/?
contaminated water & imported foods
cyclospora disease
explosive, non-bloody diarrhea, profound fatigue
acid-fast positive, autofluorescent oocyte
cyclospora
protozoa w/ large central vacuole & multiple nuclei around rim of cytoplasm
Blastocystis hominis
microbe of the large intestine
zoonotic- from pigs
contains macronucleus
Balantidium coli
