Parasite 3 Flashcards
intestinal nematode…not associated with eosinophilia (because no migrating larva)…especially prevalent in Southeaster US (due to humid/warm conditions and poor sanitation)
Trichuris trichiura
where do Trichuris trichiura attach and lay their eggs?
human cecum
how long does it take for Trichuris trichiura to become infective after being passed in the feces?
3-6 weeks
how long does it take larvae to penetrate villi of small intestine after ingestion of Trichuris trichiura egg?
3-10 days
where does Trichuris trichiura larvae go to after penetrating villi in cecum? how long does it take to develop into adult?
cecum; 1-3 months
what are some symptoms of Trichuris trichiura infection? how many worms are needed to be symptomatic?
ab pain, vomiting, diarrhea/dysentery, prolapsed rectum; more than 100
what population is most affected by Trichuris trichiura?
small children, Southeastern US
diagnosis for Trichuris trichiura
barrel-shaped egg in feces
what is treatment for Trichuris trichiura?
mebendazole (binds B-tubulin to prevent assembly)
intestinal nematode…up to 1 foot long…adults live in small intestine (largest and most common nematode)
Ascaris lumbricoides
where do Ascaris lumbricoides adults live (lay 200,000 eggs/day)?
small intestine
how long is embryonation time for Ascaris lumbricoides (eggs in stool)?
3 weeks
what is pattern of Ascaris lumbricoides development (starting with eggs hatching, ending with developing into adults)?
duodenum, mucosa, lymph, portal circulation/liver, heart, lungs, bronchioles, trachea, glottis, esophagus, small intestine
how long does it take Ascaris lumbricoides to go from ingestion to lungs? how long does it take to get to intestines (after being coughed up and swallowed back down)?
1-7 days; 2 months
this results from hemorrhages in lung due to larvae breaking out
pneumonia
where may Ascaris lumbricoides travel to?
gall bladder, liver, appendix (can also wander to anus or up to mouth)
age groups that Ascaris lumbricoides is most common
5-9 year olds
diagnosis for Ascaris lumbricoides
egg in stool or larva in sputum
what is treatment for Ascaris lumbricoides?
mebendazole/albendazole
how long are Ascaris lumbricoides viable for?
6 years
similar to Ascaris, infects dogs and cats…causes visceral larval migrans in humans (*high eosinophilia*)
Toxocara canis/cati
what is caused by Toxocara canis/cati infection?
visceral larval migrans, ocular larval migrans
major pathology of Toxocara canis/cati
tissue damage and strong immune response
what is age group most affected by Toxocara canis/cati?
1-5 year olds
diagnosis of Toxocara canis/cati
ELISA for Toxocara antigen
this larva can travel to liver to cause lesions (encapsulated larva) or to eye (becomes trapped in tissue)
Toxocara canis/cati
possible treatment for Toxocara canis/cati (but mostly self limiting)
thiabendazole
aka pinworm…intestinal nematode…humans are only host and M/F live in cecum; cause anal itch
Enterobius vermicularis
where do Enterobius vermicularis females migrate to and deposit their eggs (5000-15000)
anus/perianal region
how long does it take Enterobius vermicularis eggs to become infective after being deposited in perianal region?
4-6 hours
how long is the life cycle for Enterobius vermicularis ?
2 weeks
where is it common to find Enterobius vermicularis (30-40 million infected in US and Canada)?
prisons/dorms, clothing and bedding
diagnosis for Enterobius vermicularis
scotch tape test
what is treatment for Enterobius vermicularis (treat family simultaneously)?
pyrantel pamoate or mebendazole
threadworm…intestinal nematode…larvae penetrate unbroken skin and can cause dysentery, bronchitis, damage to intestinal mucosa (*snake like rash around anus*)
Strongyloides sterocoralis
intestinal larvae that can penetrate
filariform
Strongyloides sterocoralis develops into filariform larvae in gut and invade mucosa
autoinfection
path of Strongyloides sterocoralis infection (from penetration to residing in intestine)
penetrate unbroken skin, blood, heart, lungs, breakout air sacs, trachea, small intestines
symptoms of heavy infection of Strongyloides sterocoralis
dysentery, bronchitis, damage intestinal mucosa, (bacterial invasion and enteritis)
noninfective, feeding form of Strongyloides sterocoralis (eggs hatch into these in small intestine)
rhabditiform larvae
diagnosis of Strongyloides sterocoralis (need multiple stool samples)
rhabditiform larvae or eggs in feces
treatment for Strongyloides sterocoralis for hyperinfection (in immunocompromised patients); what is treatment option?
invermectin; thiabendazole
where is Strongyloides sterocoralis found?
warm, moist areas (South especially…400K infected in USA, 200 million worldwide)
aka hookworm…intestinal nematode…attach to mucosa of small intestine and suck blood (.1 ml blood/day/worm)
Ancylostoma duodenale/Necator americanus
what is life span of Ancylostoma duodenale/Necator americanus (10-30,000 eggs/day)
2-5 years
length of embryonate period for Ancylostoma duodenale/Necator americanus (eggs in feces)
1-2 days
free living larvae that feeds…forms after 1-2 embryonic period of Ancylostoma duodenale/Necator americanus
rhabditiform larvae
Ancylostoma duodenale/Necator americanus rhabditiform larvae develop into this…how long do these live?
filariform larvae; 4-6 weeks
where does Ancylostoma duodenale/Necator americanus commonly penetrate skin?
in between toes
need more than this many Ancylostoma duodenale/Necator americanus worms to become symptomatic (500=serious infection)
50
this characterizes cutaneous phase of Ancylostoma duodenale/Necator americanus infection
ground itch
this can occur during pulmonary phase of Ancylostoma duodenale/Necator americanus infection if large numbers of larvae are present
bronchitis
how much blood is sucked per day for Ancylostoma duodenale hookworm? how much for Necator americanus hookworm?
.2 ml/day; .02 ml/day
symptoms of Ancylostoma duodenale/Necator americanus infection
anemia, weakness, N/V, diarrhea
Ancylostoma duodenale / Necator americanus in infant children can cause these symptoms
physical, mental, sexual retardation
infection rate of Ancylostoma duodenale / Necator americanus in USA
4%
these factors favor transmission of Ancylostoma duodenale / Necator americanus
improper disposal, sandy soil, warm/moisture, no shoes
diagnosis of Ancylostoma duodenale / Necator americanus
hookworm in stool/occult blood
treatment for Ancylostoma duodenale / Necator americanus
mebendazole, supplement with iron, vitamins
how many are infected in USA with Ascaris lumbricoides?
1 million
how many in USA are infected with Trichuris trichiura?
2 million
how many in USA are infected with Strongyloides sterocoralis
400k
aka hookworm….of dogs and cats, humans are accidental host; cutaneous larvae migrans
Ancylostoma braziliense
where does Ancylostoma braziliense larvae migrate? how far do they migrate?
subcutaneous area; inch/day
infection rate of Ancylostoma braziliense in South?
20%
max life expectancy of Ancylostoma braziliense
1 year
characterizes Ancylostoma braziliense cutaneous larvae migrans…
creeping eruptions (move along subcu because can’t penetrate)
diagnosis of Ancylostoma braziliense
lesion on hands/feet/buttocks (due to tunnels larvae is making)
treatment for Ancylostoma braziliense
thiabendazole or ivermectin
tissue nematode…infect swine (7/1000); invades mucosa, larva migrate, penetrates skeletal muscle
Trichinella spiralis
how do we acquire Trichinella spiralis
cysts in raw pork
where do adult Trichinella spiralis live?
small intestine
how long does female Trichinella spiralis invade mucosa/lymph nodes? then produces live larvae that carried by blood/lymphatics
5-10 days
where do Trichinella spiralis larvae encyst?
skeletal muscle (esp. tongue and diaphragm)
what is host’s reaction to Trichinella spiralis encysting in skeletal muscle? how long does it take for host to do this?
calcify cyst; 6 months - 2 years
this amount of Trichinella spiralis will be asymptomatic
1-10 larvae
symptoms of Trichinella spiralis invading intestinal mucosal (stage 1)
diarrhea, N/V, ab. pain
symptoms of Trichinella spiralis larvae migrating (stage 2)
edema, fever, eosinophilia, inflammation heart
how long does it take intense muscular pain to subside after Trichinella spiralis larvae penetrate skeletal muscle (stage 3)?
several months
infection rate of Trichinella spiralis (2/3 reported cases involved USDA pork)
4%
diagnosis of Trichinella spiralis
larvae in muscle
treatment for Trichinella spiralis
mebendazole, pain relievers, albandazole (not completely effective, bc can’t get all tissue larva)