GI Protozoan
Giardia lamblia
Causes Giardiasis steatorrhea
Transmission
Found worldwide
Zootonic
Contaminated Water
Cysts are very resistant. They resistant chlorine
S/s
Produces mild but persistent diarrhea
⭐First sign is an explosive, foul smelling, watery diarrhea⭐
Followed by bloated abdomen
Large amounts of foul smelling intestinal gas
Long term symptoms
Abdominal pain
Nausea
Occasional episodes of diarrhea
Symptoms last a few days
Stomach acid is what stimulates the cysts to transform into tropho
Cryptosporidium
Causes cryptosporidiosis
Transmission
Cases of them contaminating municipal water systems
Can tolerate chlorine #
Real big problem in immunocompromised patients
S/s
Abdominal pains
Bloody, watery stools
Biggest concern is dehydration and loss of electrolytes
Dx
⭐Acid fast positive cysts⭐
Tx
No effective antimicrobial therapy
Fluid replacement
Good hygiene
Readily found in surface water in US
Crypts are found in drinking water
Balantidium coli
Cysts are the infective phase
Cysts are round and have a tough heavy wall
Trophozoites are mobile by cilia
S/s
Can cause ulceration of the colon
Chronic diarrhea
Nausea
Weight loss
⭐In worst case, proliferates intestine⭐
Common everywhere
Anisakis
Nematodes are roundworms
Transmission
Has a complex life cycle, which passes through a number of hosts
Eggs in water. Eggs are eaten by crustaceans. The crustaceans are eaten by fish or squids. Fish are then eating by larger mammals. Larger mammals come down with the infection.
Usually associated with fish that are either consumed raw, lightly pickled, or lightly salted
Areas of highest prevalence are scandinavia for cod, the netherlands for herring, pacific coast of south america for sveciae, japan for sushi and sashimi
Freezing and heating will kill the Anisakis
S/s (Within a few hours)
Violent abdominal pain
Nausea
Vomiting
Humans are a dead end host. Parasites cannot survive in humans and eventually dies.
Treatment only if obstructs bowel
Fasiola
Fluke or trematodes
Common to Africa and Asia
S/s
Fever
Abdominal pain
Loss of appetite
Flatulence
Diarrhea
⭐Hives⭐
Enlarged liver and spleen
Jaundice
Nematodes or Roundworms
⭐Reproduce Sexually⭐
Definitive host is the one that harbors the adult sexual form of the parasite
Intermediate host harbors the developmental stages.
Ascaris lumbricoides
Largest of the human parasites
Transmission
Found worldwide. In the southern US, quarter of population is infected
⭐Present where sanitation is poor and where human feces is used as fertilizer⭐
Once they get into the intestinal tract, they form a WORM BALL
This can cause obstruction of the intestines
Infected dogs, cats, or raccoons by fecal oral route
Infection is visceral larvae migrans or creeping eruption
Dx
⭐Looking for eggs or worms in feces ⭐
Treatment is antiparasitics
Enterobius vermicularis (Pin Worms)
Probably the most common
More common in children
Small white worm
It seldom causes serious disease, but can cause serious discomfort
Transmission
Fecal Oral
Bed clothes, sheets, towels, dust, where the eggs resist drying
Eggs hatch in intestines
Dx
Scotch tape prep
⭐Perianal itching⭐
They can also migrate further and cause genital urinary problems
Treatment
Antiparasitics on entire family and friends
Control is good personal hygiene
⭐Dusting with a damp mop⭐
Necator americanus New world hookworm
Transmission
Soil contaminated with the eggs
Fecal cutaneous
S/s
Local itching and irritation
Anemia from slow blood loss
Cat and dogs
Cutaneous larvae migrans happens when larvae can’t make it to circulatory system so they keep traveling around skin until they die
⭐Redness and actually see the worms moving⭐
Treatment
Antiparasitics
Folic and iron supplements
Strongyloides stercoralis
Common to tropical areas
Differ from the hookworms in that their eggs hatch into larvae in the intestines
Free living non parasitic cycle can be established outside the human body
These worms can perforate the intestinal wall resulting in a serious bacterial septicemia
In immunocompromised, they can reinfect the same host
Passing through the skin, they usually do not damage. When they pass through the lungs, patient gets cough or wheezing
In intestinal tract, patient is usually asymptomatic
Only when the number of worms gets large that the patient might complain of pain, vomiting, diarrhea
Dx
Difficult
Treatment is antiparasitics
Tapeworms
(Cestodes)
Ribbon like worms
Have a scolex head
Segments are proglotides
They will anchor themselves to intestinal mucosa by scolex
Proglottids are self contained units
Transmission
Ingested cysts from pork, beef, or fish
Usually a mild infection
Second type of infection is the deep tissue infection.
Result of ingesting eggs from pork tapeworm
Cysticercosis - Seems to be very common in SW part of US
Eating meat or fish that is improperly cooked
Chopped meat that’s infected.
Species
Taenia saginata - Beef tapeworm
Taenia solium - Pork tapeworm. Less common.
Diphyllobothrium latum - Fish tapeworm. Pretty common. Great lakes. One side effect is B12 anemia.