Parasites Review Lecture Notes Flashcards
What is the Taxonomy name for a Tape Worm
Cestode
What is the head of the tapeworm called
A scolex
What are the individual segments of an tape worm called
proglottids
What is a chain of proglottids called
A strobilli
Was is the sex of a cestodes
Hermaphrodites
What is the digestive system of cestodes
They dont have one
Can humans serve as the intermediate host of cestodes
Yes
When humans are the host for cestodes what happens
We get the “baby” tape worm
When humans are the Intermediate host for tapeworms ( cestodes) what happens
Cysiticercosis
Echinococcosis
Sparganosis
In cestodes, is it worse to be the initial host or the intermediate host
Intermediate host
What is the difference between Taenia solium and Cysticerosis
They are the same parasite and the same egg.
If egg is ingested: you’ll be the intermediate host. S/s cysts
If larva is ingested: you’ll grow an adult tapeworm that will release eggs.
How does someone get cysticerosis
Contact with human feces
Eating the T. Solium eggs
How is Taenia Solium ingested
By eating undercooked pork
What are the S/s of Taenia Solium
Indigestion and Diarrhea
What is the sign of someone with cysticercosis
Development of cyst following ingestion of T. Solium
How do you prevent ingestion of T. Solium
Cooking pork
How do you prevent Cystercosis
Proper Saniation
Avoiding feces
What is the name for the Cow Tape worm
Taenia Saginata
Are humans the intermediate host for Taenia saginata
No, the cow is
How is Taenia saginata ingested
By eating undercooked beef or contact with human feces
S/s of ingesting Taenia saginata Aka Cow tapeworm
Can be asymptomatic
Vagua abdominal pains
Chronic indigestion
Hunger pains
How can you prevent ingesting Taenia saginata
Cook meat properly and sanitation
What is the definitive host for Cow Tape worm
Aka Taenia saginata
Definitive host humans
What is the name for the Fish Tape worm
Diphyllobothrium Latum
What is the structure of proglottids for the fish tape worm
Aka diphyllobothrium latum
Structure: wide flat and thin
What are the two intermediate hosts for diphyllobothrium latum
The crustacean and freshwater fish
How is Diphyllobotrium latum ingested
Eating fish carrying the tapeworm
How are humans infected by Diphlyllobothrium latum
Eating raw or undercooked fish
Where is Diphyllobothrium latum most prevalent
In cool lake regions
Where raw or pickled fish is popular
What are the most common causes of Diphyllobothrium latum ingestion
Cooking fish over campfires or geflite fish
What are the s/s of diphyllobothrium latum infection
Usually asymptomatic
Occasionally Epigastric pain, abdominal cramps, N/V, and weight loss
40 percent of patients who ingest Diphyllobothrium latum present with what finding
Low b12
What is the larva form of D. Latum
Sparganosis
How is sparganosis ingested
(Larva form of D. Latum)
Drinking pond or ditch water that contains crustaceans (copepods)
Eating tadpoles, frogs, or snakes
What are the S/s of sparganosis ingestion
Painful inflammatory tissue reactions in subQ tissue
In the eye: painful, periorbital edema, corneal ulcers and ocular involvement
If there are hydatid cycst… think…
Echinococcos granulosas
Where is echinococcus most prevalent
In sheep farmers
How is Echinococcus ingested
Contaminated water or vegetation from sheep or canines
Hand to mouth transmission of canine feces
What are teh S/s of Echinococcus granulosus
Cysts!
When diagnosing Echinococcus granulosus what must you be cautious of..
Aspiration might confirm the diagonis but has a HIGH risk of anaphylaxis reaction.
If you are going to aspirate a Echinococcus granulosus cyst what should you add…
Formalin
Where does the Adult Echinococcus Granulosus reside in its definitive host?
In the bowel
Are humans the intermediate or definitive host for E. Granulosus
No
What are the hosts for Echinococcus multilocularis
Rodents, foxes, wolves, dogs, cats
What is the intermediate host for E. Multilocularis
Rodents
How are humans infected with cyst stage E. Multilocularis
Contact with foxes, dogs, or cat feces contaminated with eggs
What occupation is most associated with E. Multilocularis
Trappers
Handle fur pelts and inhale fecal dust with the eggs
What causes hydatid cycst in the liver and lungs
E. Multilocularis
What egg tapeworm mimics the appearance of carcinoma
E. Multilocularis
Because there are no protoscolices
What tapeworm causes obstruction of the biliary and portal pathways in the liver
E. Multilocularis
What tapeworm mimics hepatic cirrhosis
E. multilocularis
-malnutrition, ascites, and portal hypertension
If left untreated what is the mortality rate of E. multilocularis
70 percent
How do you prevent E. Multilocularis
Deworming farm dogs and cats
What is the size of hymenolepis nana
Dwarf tapeworm 2-4cm
Does hymenolepis nana require and intermediate host
No
Do hymenolepis nana need to leave there host at any point?
No
Eggs are able to hatch into larva, then grow into adults, without leaving the host
Can lead to hyper infection and several clinical symptoms
Other than humans what two vectors are associated with hymenolepis nana
Beetles and mice
What is the most common tape worm in N. America
Hymenolepis nana
What are the places you can ingest Hymenolepis nana from
Contaminated grain and flour
Day Care centers for children are hot spots
What are the S/s of Hymenolepis nana
Heavy infection:
Diarrhea, abdominal pain, headache, anorexia.
Because Hymenolepis nana doesn’t need to leave its host, this can cause
Auto reinfection and severe symptoms
What does H. Nana egg look like
Six hooked embryo and polar filaments
What is a tapeworm that is closely related to H. Nana and primarily found in rats and mice
Hymenolepis diminuta
What is the physical difference between H. Nana and H. Diminuta
The scolex of H. Diminuta lacks booklets, and the egg is larger and has no polar filaments and is bile stained
What does the lifecycle for Hymenolepis diminuta require
Requires insect for development
How do humans ingest Hymenolepis diminuta
Larval insects feed on infected rat feces and humans eat the larva in contaminated grains
What is the cause of H. Diminuta ingestion
Rodent contamination/ worms in uncooked grains
What are the S/ s of H. Diminuta infection
Can be asymptomatic
Or cause N/D abdominal discomfort, anorexia
What is the physical characteristics of H. Diminuta
Bile stained egg that lacks polar filaments
How do you prevent H. Diminuta
Rodent control where grain is stored
Dipylidium caninum is primarily a worm associated with what animal
Dogs and Cats
What is the life cycle for dipylidium caninum
Development off larva worms in dos and cat fleas
What do the eggs of dipylidium caninum look/ present
Free eggs are rarely seen
Egg packets that contain 8-15 six hooked on o sphere in a thin membrane are most commonly found in fecal specimens
What is the cause of Dipylidium caninum infection
Pet chews/ crushed fleas, licks a child mouth or direct swallowing infected fleas leads to intestinal infection
Who is most at risk of dipylidium caninum
Children near dogs and cats
What are the S/s of Dipylidium Caninum
Light- asymptomatic
Heavier- abdominal discomfort, anal pruritus, and diarrhea
What causes the anal pruritus associated with D. Caninum
Motile proglottids
How do you diagnose D. Caninum
Microscopic eggs in feces
Or Visible proglottids in feces
(Stool sample)
What is the name from Flukes
Trematodes
What is the shape of trematodes
Flat, fleshy, leaf shaped worms
What is the digestive system of trematodes
Aka flukes
Lateral tubes that do not join to form an excretory opening
What is the sex of most flukes and what is the exception
Hermaphroditism except for schistosomes
What do flukes require as their first intermediate host
Mollusks (snails and clams)
All flukes have an operculum except for the
Schistosomes
What is the largest, most prevalent, and most important intestinal fluke
Fasciolopsis buski
What is another name for Fasciolopsis buski
The giant intestinal fluke
How do humans ingest Fasciolopsis buski
Ingesting the metacercaria (encestes larva) on water chestnuts or water plants
Where do the metacercaria of fasciolopsis buski develop into immature flukes
In the Duodenum
Where does the adult fluke of Fasciolopsis buski attach to and what does it do there
In the mucosa of the small intestine and undergoes self fertilization
How long does it take F. Buski to go from ingestion to eggs
3 months
What is the free swimming larva of F buski called
Miracidium
What is the reservoir for F. Buski
Needs snail host
And in china, Vietnam, indonesia, maylasia, and India pigs, dogs and rabbits serve as reservoir host
What are the S/s of F. Buski infection
Inflamation, ulceration, and hemorrhage.
Feels like a duodenal ulcer,
Diarrhea Malabsorption syndrome similar to giardiasis Intestinal obstruction Marked eosinophilia (RARELY CAUSES DEATH)
What does F. buski look like
Large, golden, bile stained egg with operculum on the top
What is the name of the sheep liver fluke
Fasciola hepatica
What organ does Fasciola hepatica migrate through
Migrates through the liver parenchyma and enter the bile ducts to become adult worms
At approx 3-4 months after F. Hepatica infection what do the adult flukes start to do..
Starts producing operculated eggs that are identical to F. Buski
What are the S/s of F. Hepatica
Liver irritation, tenderness, and hepatomegaly.
Pain in the RUQ, chills, fever, and marked eosinophilia
Worms in bile ducts cause irritation and toxic secretion leading to hepatitis, hyperplasia, and biliary obstruction
Can cause LIVER ROT
Portal cirrhosis is common
How do you diagnose F. Hepatica
Eggs are indistinguishable from F. Buski
Eggs in bile is diagnostic
What is the name for the Chinese liver fluke
Clonorchis sinensis
How many intermediate host does C. Sinensis require
2 intermediate hosts
What is unique about C. Sinensis (fluke)
Differs from other flukes in that the eggs are eaten by the snail where reproduction begins
What are the two intermediate hosts for C. Sinensis
- Snail
2. Fresh water fish
After ingestion by its secondary host (fresh water fish ) C. Sinensis does what…
Fresh water dish ingest the cercaríae cyst where it develops into infect metacercariae
What is the way in which humans ingest C. Sinensis
Uncooked freshwater fish are eaten
Flukes develop in the duodenum and then migrate to the bile ducts to become adults
How long can C. Sinensis survive in the biliary tract
50 years producing 200 eggs a day
What population has common C. Sinensis
Asian refugees
What are the reservoirs and hosts for C. Sinensis
Raw, pickled, smoked, or dried freshwater fish that harbor the metacercariae
Dogs, cats, and fish eating mammals can serve as reservoirs as well
What are the S/s of C. Sinensis
Usually asymptomatic
Severe infections occur with many flukes in the biliary ducts
-Fever, diarrhea, Epi gastric pain, hepatomegaly, anorexia, jaundice
Can cause biliary obstruction
Can Cause adenocarcinoma of the biliary duct
Invasion of the gall bladder can cause cholecystitis, cholethiasis, and impaired liver function
How do you diagnose C. Sinensis
Eggs in stool
Repeat stool cultures may be necessary
In acute symptomatic infection: ther are usually eosinophilia and an elevation of serum alkaline phosphate levels.
Radiographs may detect abnomalities in biliary tract
What is the name for the Lung Fluke
Paragonimus westermani
When does the infectious stage for P. Westermani occurs
In a secondary intermediate host: the muscles and gills of freshwater crabs and crayfish
How do humans ingest P. Westermani
Ingest infected meat, larval worm hatches in the stomach and ends up eventual in the plural cavity
Where does the adult worm for P. Westermani reside
In the lungs where it produces eggs that are liberated from ruptured bronchioles and appear in the sputum or when ingested in the feces
What are the two intermediate hosts for P. Westermani
Snails
Crayfish/ Crab
What is the cause of P. Westermani ingestion
Consumption of uncooked freshwater crabs and crayfish
What are the S/s of P. Westermani ingestion/ infection
Fever, chills, high eosinophilia
In the lungs, adult flukes produce, Inflamation, with fever, cough, and increased sputum
Blood sputum with eggs (rusty sputum)
And severe chest pain
Can cause dyspnea , chronic bronchitis, bronchiectasis, and pleural effusion
As well as fibrosis in the lungs
If larva migrate to the spinal cord or brain then there may be severe neurological disease
How do you diagnose P. Westermani
Sputum and Feces reveal golden brown, operculated eggs.
Chest Radiographs show infiltrates, nodular cysts, and pleural effusions.
Where is Schistosomes a major parasitic infection
Tropical Areas
230 million infections worldwide
What do schistosomes cause
Schistosomiasis, aka bilharziasis or snail fever
Snail fever aka
Schistosomiasis
How are schistosomes different than flukes
Obligate intravascular parasites
Skin penetrating not ingested
Have no operculum
And are Male/ Female not hermaphroditism
Where do schistosomes develop in humans
In the intrahepatic portal circulation
Or in the visceral, prostatic, rectal, or uterine plexuses/ veins
What is the vector for schistosomes
Snails
What accounts for the chronic infections associated with schistosomes
The can coat themselves with substances that the host recognizes as “self”
Where as S. Mansoni and S. Japonicum found…
In the Mesenteric veins
Intentional schistosomiasis
Where is S. Haematobium found..
In the veins around the urinary bladder
Vesicular schistosomiasis
What do the eggs of schistosomes elicit in their host..
Intense inflamarte reaction with mononuclear and polymorphnuclear cellular infiltrates and the formation of microabscesses
What do the large inside the eggs of Schistosomes produce
Enzymes that air in tissue destruction, allowing the eggs to pass through the mucosa and into the lumen of the bowel and bladder
What happens to schistosomes eggs when they reach fresh water
Hatch quickly realeasing motile miracidia that invade snails, become thousands of infectious cercariae, which then are immediately infectious to humans
What are the earliest signs of schistosomes infection
Penetration of the skin
Causes pruritic popular rash
What is Katayama syndrome
The onset of oviposition result in a symptom complex
Fever, chills, cough, urticaria, arthalgias, lymphadenopathy, splenomegaly, and abdominal pain.
Seen 1-2 months following primary exposure to schistosomes.
(May persist for 3 months)
What causes the more chronic and signifigant phase of schistosomiasis
Presence of eggs in tissues resulting the formation of granulomas and fibrosis.
Causing intense Inflammation and scarring.
Where do S. Mansoni usually reside
In the small branches of the inferior Mesenteric vein near the lower colon
What do the eggs of S. Mansoni look like
Oval, with a sharp lateral spine, and measure 115 to 175 um x 45 to 70 us
What is the most widespread schistosomes
S. Mansoni
Endemic to africa, Saudi Arabia, and Madagascar
What are the reservoir hosts for S. Mansoni
Primates, marsupials, and rodents
Why is S. Mansoni considered a disease of economic progress..
The development of massive land irrigation projects in desert and tropical areas results in the dispersion of infected humans and snails to previously uninvolved areas
What is the host for S. Mansoni
Snails
What are the S/s of S. Mansoni
Itch, rash, cough, hepatitis
Goes from ski to lungs to liver,
Chronic: hepatospleganomegaly, ascites, white psuedotubercles on liver.
Eggs can appear in spinal cord and lungs.
What occurs in fatal schistosomiasis
From S. Mansoni
Fibrous tissue, surrounds the portal vein in a thick, grossly visible layer, - clay pipe stream fibrosis
Where does S. Japonicum reside
In the superior Mesenteric vein around the small intestine and in the inferior Mesenteric vessels
What are the characteristics of S. Japonicum eggs
are smaller, spherical, and posses a TINY spine.
Because of the smaller size of S. Japonicum, what does this cause
A more severe infection of more tissue
Which Schistosomes frequently involves infection of cerebral structures
S. Japonicum
What are the S/s of S. Japonicum
Cerebral inclusion:
Lethargy, speech impairment, visual defects, and seizures
Other S/s common with S. Mansoni
Katayma syndrome more common
How do you diagnose S. Japonicum
Stool sample showing small, golden eggs with tiny spines.
What population is common infection with S. Japonicum
People who work in rice paddies and on irrigation projects
What is the common name for S. Japonicum
Oriental blood fluke
What is Schistosoma Haematobium
Is a blood fluke that developes in the liver and migrates to the veis al, prostatic, and uterine plexuses of the Venus circulation and occasional in the portal bloodstream
What do S. Haematobium eggs look like
Large eggs with a sharp terminal spine
Where do S. Haematobium eggs deposite into
The walls of the bladder and uterine and prostatic tissues.
In the bladder they can break free and are found in the urine
What is the leadind cause of bladder cancer in Egypt
S. Haematobium
What is the reservoir for S. Haematobium
Monkeys, baboons, and chimpanzees
HOST: snail
What are the S/s of S. Haematobium
Similar to S. Mansoni and Japonicum
Includes: hematuria, dysuria, and urinary infrequency.
Bacteriuria is a frequent chronic condition.
Scarring of the bladder, with loss of bladder capacity and obstructive uropathy.
Bladder cancer
Can Also present in the lungs:
Causing dyspnia, cough, and hemaptosis
What is the cause of swimmers itch
Cercarial dermatitis
Nonhuman schistosomes that penetrate the skin and produce dermatitis
What is the natural host for Cercarial dermatitis
Birds, offshoot feeding animals, freshwater lakers.
What is a nematode
A round worm
What are the physical characteristics of Nematodes
Large, Cylindrical, unsegmented bodies
Where do Nematodes primarily live in the body
In the intestinal tract
What is the name of the Pinworm
Enterobius vermicularis
What is the life cycle of the pin worm
Aka enterobius vermicularis
Ingestion of embryonated eggs Larvae hatch in s. Intestine Migrate to L. Intestine Where they mature for 2-6 weeks Eggs are laid in perianal folds
Where is the hot spot for the pin worm aka enterobius vermicularis
Crowded conditions like day care centers, schools, and mental institutions
What is the most common helminthic infection in N. America
Enterobius vermicularis
Does enterobius vermicularis have a known animal reservoir
No
What is the cause of enterobius vermicularis
Eggs are ingested and the larval worm develops in the intestines
What occupation is common infection with enterobius vermicularis
Infected Workers who handle food can be a source of infection
What are the S/s of enterobius vermicularis aka pin worm
Most asymptomatic
If allergic: pruritus, loss of sleep, and fatigue
Scratching/ itching can lead to secondary bacterial infection
How do you clinically diagnose Pin worm infection
Detection of the eggs on the anal mucosa.
Scotch tape prep
What nematode do you have to be careful of when dusting a house
Enterobius vermicularis
The pinworm
What correlates with an Enterobius vermicularis infection
Dientamoeba fragilis
What is the life cycle for Ascaris lumbricoides
Ingested egg releases a larval worm that penetrates the duodenum
Then enters the blood stream and goes to the liver and heart, then enters pulmonary circulation
Larvae freak free in the alveoli, larvae are coughed up, swallowed, and return to the S. Intestine.
What causes Ascaris lumbricoides infection
Ingestion of eggs
Poor sanitation where human feces is used as fertilizer
What is the most common helminthic infection in the world
Ascaris lumbricoides
Ascaris lumbricoides is similar to what other nematode…
How are they different
Similar to Ascaris suum
Different in that A. Suum is found in pigs/ swine farmers
And A. Lumbricoides has no animal reservoir
What are the S/s of A. Lumbricoides
Usually none, but could migrate tot he bile duct/ liver and cause peritonitis
In the lungs can cause pneumonitis, may be occompained by eosinophilia/ O2 desat.
Abdominal tenderness ,fever, distention, and vomiting
What will A. Lumbricoides do in response to fever and drugs used to treat ascaiasis
Can migrate to other areas
How can A. Lumbricoides be diagnosed
Finding larvae in the sputum
Where does toxocara and Baylisascaris come from
From eggs from infected dogs, cats, and raccoons
Who is most susceptible to Toxacara and Baylisascaris
Childeren
What diseases does Toxocara and Baylisascaris cause
VLM ( visceral larva migrans)
NLM (neural larva migrans)
OLM (ocular larva migrans)
What is the cause of Toxacara and Baylisascaris infection/ ingestion
Exposure to contaminated feces
What are the S/s of Toxocara and Baylisascaris
The larvae may invade the body tissues causing VLM, NLM, OLM
Bleeding, eosinophilic granulomas, and NECROSIS
What are the common anatomical sites for a Toxocara and Baylisascaris infection
The lungs, heart, kidneys, liver, muscles, eyes, and CNS
How do you diagnose Toxocara and Baylisascaris
Eosinophilia, known exposure to dogs, cats, and raccoons,
Will you find adult worms with Toxocara and Baylisascaris
NO
What nematode should you use corticosteroids with
Toxacara and Baylisascaris to treat pulmonary, myocardial, or CNS involvement
What is the name of whip worm
Trichuris trichiuria
Where is trichuris trichiuria common
In places where human feces is used a fertilizer
What is the cause of Trichuris trichiuria
Exposure to contaminated feces
What are the S/s of trichuris trichiuria
Aka whip worm
Usually asymptomatic
Can have secondary bacterial infection from deeply penetrating heads in the intestinal mucosa.
Abdominal pain, bloody diarrhea, weakness, and weight loss.
Can have associated appendicitis
In children can have prolopse of rectum
What are the S/s of a severe T. Trichiuria infection
Anemia and eosinophilia
How do you diagnoses T. Trichiuria
Finding eggs in stool
Bile stained eggs with polar light infestations
What are the three Toxacara and Baylisascaris
T. Canis (dogs)
T. cati ( cats)
B. Procyonis ( raccoons)
Which nematode can cause appendicitis
T. Trichiuria
What is the name for hook worms
Anclyostoma duodenale and Necator americanus
Where is the hook worm usually found
In feces deposited good soil
How is A. Duodenale and N. Americanus acquired by the host
Walking barefoot in contaminated soil
What are the S/s of A. Duodenale and N. Americanus
Rash at site of entry
Pneumonitis and Eosinophilia
Microcytic hypochromic anemia from blood lost from feeding worms
What can occur in severe cases of A. Duodenale and N. Americanus infections
Sever Hookworm infection
-emaciation, mental and physical retardation
Ancylostoma Braziliense is a natural parasite of what animals
The intestines of dogs and cats
Accidentally infects humans
What is the causitive agent of cutaneous larva migrans aka ground itch or creeping eruptions
Ancylostoma braziliense
What happens to Ancylostoma Braziliense when it penetrates the skin
Can’t go further, wanders in the subQ tissue making serpentine tunnels
What is the geographical region for A. Braziliense
Beaches of tropical regions in the summer
What is the cause of A. Braziliense infection
Children playing with soil or sandboxes contaminated with animal feces
What are the S/ s of A. Braziliense infection
Can cause erythematous and vesicular reactions,
Pruritus and scratching may lead to bacterial infection
About half of pts develop transient pulmonary infiltrates with peripheral eosinophilia (loifer syndrome)
How do you diagnose A. Braziliense
Clinical appearance of the tunnels and a history of contact with dog, cat feces
Larvae rarely found in sputum
What nematode is associated with sexual transmission
Strongyloides stercoralis
What are the S/s of Strongyloides stercoralis
Pneumonitis
Intestinal infection is usually asymptomatic
Can effect the biliary and pancreatic ducts, small bowel, and colon, causing inflammation and ulceration,.
N/V/D
If the host has a compromised immune system what can happen with S. Stercoralis infection
Can cause hyper infection syndrome
How does S. Stercoralis present/ diagonised
Usually low numbers are passed in the stools,
So you need three stool samples (one per day for three days) because the larva may occur in “showering” : some larvae one day and none the Next
What does trichinella spirals cause
Trichinosis
Where does T. Spiralis live
In the gut of flesh eating animals
Commonly the pig
What is the life cycle fo T. Spiralis
Ingestion of larvae in meat Develop into adult worms Move to intestinal mucosa then to the blood stream Then to muscle tissues Where they calcify
Common targets( extraocular eye muscles, the tongue, deltoid, pectoral, intercostal, diaphragm, and gastrocnemius muscle)
How is T. Spiralis ingested
Associated with eating improperly cooked pork
Polar bears and walruses can be infected with…
T. Spiralis (its resistant to freezing )
What are the S/s of T. Spiralis
<10 larva: asymptomatic or flu like, diarrhea
>100: have signifigant disease
>1000: occasional death , persistent fever, gastrointestinal distress, marked eosinophilia, muscle pain, and periorbital edema,
“Splinter” hemorrhages beneath nails
Severe neuro signs including psychosis, menigioencephalitis, and CVA
What is the vector for Wuchereria Bancrofti and Brígida malayi
the mosquito
Where do the larva of W. Bancrofti and B. Malayi migrate to
Lymphatic system
Primarily in the arms, legs, groin
How many months after initial infection do W. Bancrofti and B. Malayi find their way to blood cirulcation
3-12 months
What is the diagnostic marker for W. Bancrofti and B. Malayi
Microfilaria in the blood
What is the life cycle for W. Bancrofti and B. Malayi
In the mosquito: larvae develop into third stage larvae and are transmitted when the mosquito feeds
In the human: can persist for as long as 10 years
What bacteria does W. Bancrofti and B. Malayi harbor
Bacterial endosymbionts (depend on these to reproduce)
Where is W. Bancrofti prevalent
In tropical regions
No known animal reservoir
Where is B. Malayi prevalent
In Asia with Cats and monkeys as reservoir
How does W. Bancrofti and M. Malayi get into its host
Mosquito bite
What are the S/s of W. Bancrofti and B. Malayi
Acute lymphangitis and lymphadenitis with fever/ chills.
Enlarged lymph nodes in extemites, scrotum, and the testes.
Can cause elephantiasis
What is the vector for Loa Loa
Bitting Fly
What is the time line of infection from Loa Loa
Approx 6 months after infection, the production of microfilariae starts and can persist for 17 years of more
Where is Loa loa prevalent
In the rain forest of Africa
Where monkeys and mango flies are the reservoir host
How does Loa Loa get into its host
Bites from a Fly
What are the S/s of Loa Loa
Asymptomatic for 12 months
Then fugitive swelling/ CALABAR swelling (painful/ pruritic)
Worm can migrate to under the conjunctiva
When is Loa Loa primarily found
During the daytime from 10 am to 2 pm
What drug do you want to use to treat the S/s associated with Loa Loa
Corticosteroids to reduce inflammation of the traveling worm
Where is Mansonella Perstans found
Africa, Central and South America
Reservoir host are chimpanzees and gorillas
What is the vector for mansonella perstans
Biting midges or black flies
What are the S/ s for mansonella perstans
Generally asymptomatic
May causes dermatitis, lymphadenitis, hydrocele, and elephantiasis
How does mansonella perstans present in the blood
Nonsheathed microfilariae in the blood
Where is Mansonella ozzardi found
In central and South America, West Indies
No know reservoirs
What is the vector for mansonella ozzardi
Mixing midges and Black flies
What are the s/s of Mansonella ozzardi
The exact same as M. Perstans
Where is Mansonella streptocerca found
In the congo basin,
Reservoir in monkeys
What is the vector for Mansonella streptocerca
Biting midges and black flies
What are the S/s of Mansonella streptocerca
Usually asymptomatic, can produce edema and rarely elephantiasis
What is the vector of Onchocerca volvulus
The larvae enters the skin of the host from the bite of the black fly
What is the timeline/ life span for O. Volvulus
Larvae migrate to SubQ tissue where they are surrounded by fibrous nodules which can remain for 15 years
What do all individual worms and all life cycle stages of O. Volvulus contain
The wolbachia bacteria endosymbionts
Where is O. Volvulus most found?
Africa, central and south America
Black flies that breed in fast flowing streams
50 % of people infected by O. Volvulus will progress to what..
River blindness
What are the S/s of O. Volvulus infection
Fever, eosinophilia, and urticaria.
Subcutaneous nodules on the body
Can cause blindness
Wolbachia bacteria releases microfilariae death in the cornea and causes edema and opacity
How do you diagnose
O. Volvulus
Presence of microfiliraie in skin snip preps
What is the name for the Dog Heartworm
Dirofilaria immitis
What is the worm that creates a coin legion in the lung mostly in dogs and rarely in humans
Diroliaria immitis
Where is Dracunculus medienesis found ?
Asia and Africa
People bath in step wells and the female worm discharges larvae on the arms legs and feet on cyclops in water
Human infection is from ingestion of water containing cyclops
What is the cause of D. Medinesis infection
Drinking contaminated water
What are the S/s of D. Medinensis infection
A painful ulcer forms one year post infection ,
How is D. Medinensis diagnoses
Flooding the ulcer with water to recover larvae when they are discharged
What are the characteristic of an amoebae
Unicellular
Have two life cycles
- trphoziote (active feeding stage)
- cyst (resistant, infective phase)
How do amoebae replicate?
By binary fission or by development of numerous trophozoites with in the mature multinucleated cyst
How are amoebae motile
By psuedopods
How long with trophozoites remain actively motile
As long as the environment is favorable
What causes the amebae to enter the cyst phase
When the environmental temperature or moisture level drops below favorable
Where is Entamoeba Histolytica found
Highest in tropical regions,
Flys and roaches serve as reservoir,
Sewerage, human waste as fertilizer are common sources
What amebae can be passed from oral, anal sex
Entamoeba histolytica
What is the cause of E. Histolytica infection
Ingestion of contaminated food and water
Oral anal sex
What are the S/ s of E. Histolytica
None if healthy
Intestinal amebiasis: pain cramping, and colitis with diarrhea.
Severe: numerous bloody stools per day, fever, leukocytsis, rigors
Abcess formation is common, especially in the R.Lobe of the liver
Hepatomegaly and elevation of the diaphragm is observed
How are trophozoites removed from the blood in the body
By the liver
How do you ID a E. Histolytica infection
Trophozoites and cysts in stool and in tissue
Collect multiple stool samples
What does E. Polecki cause
Transient diarrhea from pigs and monkeys
Amebae
What is the minimal infective dose for humans with G. Duodenalis
10 -25 cysts
What is detected in the fecal specimens of pts infected with Giardia Duodenalis
Cysts and trophozoites forms
Where is G. Duodenalis found
Streams, lakes, and mountain resorts.
Beavers, and muskrats
What chemical is G. Duodenalis resistant to
Chlorine, so chemical plus filtration is needed
What are the S./s of G. Duodenalis
Mild diarrhea to severe malabsorption syndrome
Sudden onset of foul smelling watery diarrhea, abdominal cramps, flatulence, and steatorrhea
What is the infection timeline for G. Duodenalis
Incubation 1-4 weeks
Spontaneous recovery after 10-14 days
How is G. Duodenalis diagnosed
Stool exam fro cysts and trophozoites
1 sample for 3 days
How can G. Duodenalis be prevented
Boiling drinking water from streams and lakes
Fecal oral sex should be avoided
What is the cause of D. Fragilis infection
Possibly from person to person, inside the shell of Enterbius vernicularis (pinworm)
Via fecal oral route, oral anal routes
What are the symptoms of D. Fragilis
Mostly asymptomatic, colonization of cecum and upper colon
Some patiens develop abdominal cramps, intermittent diarrhea, anorexia, and weight loss,
(No evidence of tissue invasion)
How do you diagnose D. Fragilis
Small trophozoites with one or two nuclei in the stool
The central karyosome consists of four to six discrete granules.
Several stool samples are necessary due to fluctuating excretion
What does trichomonas vaginalis casue
Urogenital infections
T. Vaginalis exists only as a
Trophozoite
Where is T. Vaginalis found
In the urethras and vaginas of women
And the urethras and prostate glands of men
How is T. Vaginalis motile
It has four cilia and a short, undulating membrane
What is the cause of T. Vaginalis
Sexual intercourse is the primary mode of transmission
Infants can be infected from passing though the birth canal
What are the S/s of T. Vaginalis
Most women are asymptomatic or have scant watery discharge
Can cause itching, burning, and painful urination.
Men are primarily asymptomatic and serve as carrier resovoirs
What is the drug of choice for T. Vaginalis
Mettronidazole
Where is Neobalantidium coli found?
Pigs and monkeys
Transmitted fecal oral
Contaminated water supplies with pig feces.
Can be person to person
(Food handlers)
What is the cause of N. Coli
Fecal oral transmission, pigs
What are the S/ s of N. Coli
Abdominal pain , tenderness, tenesmus, nausea, anorexia, and watery stools with blood and pus
How do you diagnose N. Coli
ID very large cysts and trophozoites in stool.
Surface is curved in cilia, and have prominent internal macro nucleus with a micro nucleus as well
Where is cystoisospora found
In AIDS pts
What is the cause of Cystoisospora
Ingestion of contaminated food or water
Oral-anal contact
What are the S/s of Cystoisospora
Mild gastrointestinal disease, malabsorption, loose foul smelling stools.
Chronic diarrhea, weight loss, anorexia, malaise, and fatigue,
How do you diagnose cystoisospora
Acid fast stain or iodine
Where is sarcocystis isolated from
Pigs and cattle
How does clinical sarcocystis present in humans
If infected meat is ingested then intestinal disease,
If sporocycts are ingested then muscular disease
What are the S/ s of Sacrocsystis
Intestinal disease: N/ D, abdominal pain
Muscular: fever and muscle pain
If a pt ate raw horse meat, what orgasim could be ingested
Sarcocystis spp.
What is the cause of Sarcocystis diarrhea
15-KD actin depolymerizing factor
What are the hot spots for cryptosporidium
Pools, veterinary personnel, AIDS pts. High risk
What is the cause of cryptosporidium
Drinking contaminated water, AIDS pts, fecal oral and oral anal
What are the S/ s of cryptosporidium
Healthy; self limiting, watery diarrhea
Compromised: 50+ stools a day, fluid loss, lasts for months to years,
How do you diagnose cryptosporidium
Detection of OOcysts
Modified zinc sulfate centrifugal flotation technique or sheather sugar flotation procedure
What is cryptosporidium resistant to
Chlorination and ozone treatment
Where is cyclospora found
In reptiles, birds, and mammals.
No person to person
What are cyclospora resistant to
Chlorination
What is the cause of cyclospora
Consumption of contaminated fruits and veggies,
Also contaminated water
What are the S/s of cyclospora species
Mild nausea, anorexia, abdominal cramps, watery diarrhea
Fatigue, malaise, flatulence, and bloating, ‘severe in AIDs pts
How do you diagnose cyclospora
Light microscope of unstained fecal material (wet mount)
Appear as non reflective spherical
