Flashcards in Parasite 2 Deck (79):
Tissue response to Helminths and Vermin?
What are the eosinophilic responses?
1) IgE, mast cells
2) Eosiniphilic chemotaxic factors
3) IL-4 and IL-5
Function of IL-4?
Switch to make IgE
Most important fatal helminth disease in humans?
Death from Schistosomes caused by?
Hepatic granulomas and fibrosis
What does Schistosomiasis haematobium in Africa cause?
Hematuria/obstruction of bladder
Predisposition to squamous cell carcinoma of bladder
Where are sporocysts of Schistosomiasis?
Fresh water snails
How do fresh water snails infect humans?
They give rise to cercaria that penetrate through skin
Where do schistosome migrate after skin penetration?
Peripheral vasculature to portal venous system and pelvic venus system
How does tissue react to schistosome eggs?
Granulomas and fibrosis
What completes life cycle of schistosomes?
Eggs shed in feces that hatch in water
What causes the hepatic damage of schistosomes?
Toxic products and cell mediated immunity
Which interleukins result in induction of IgE synthesis, mastocytosis, and eosinophilia?
IL-3, 4, and 5
Resistance to re-infection correlates with what?
Eggs induce lymphocytes to secrete what?
Hallmark of Schistosomiasis?
Hepatic fibrosis out of proportion to parasite injury
Pathology of Schisto?
Calcified pinhead granulomas form around schisto egg
What do schisto granulomas induce?
Macrophages, lymphocytes, neutrophils, and eosinophils
Appearance of portal fibrosis in Schisto?
Pipestem fibrosis results in what in Schisto?
How does one get liver flukes (Clonorchis siensis)?
Eating improperly cooked fish
Where do adult flukes live?
How long do flukes live?
Chronic infection with liver flukes can cause what?
Cholangitis, cholelithiasis, pancreatitis, and cholangiocarcinoma
How does one get Taenia saginata?
Ingestion of undercooked beef
How do you get Taenia solium?
Ingestion of undercooked pork
Which Taenia causes Cysticercosus?
How does T. solium cause cysticercosus?
Eggs ingested, larvae hatch, penetrate gut wall, hematogenous dissemination results in cysts in CNS.
Which cysts in CNS cause problems?
Degenerating cysts. Intact cysts cause little host reaction
Echinococcus is known as what?
How does Echinococcus normally present?
Asymptomatic and chronic
Hydatid cysts most commonly associated with what?
Hydatid cysts most commonly in what?
Liver and lungs
Liver disease in which Echinococcus is almost always fatal?
Hydatid cysts of which Echinococcus can cause anaphylactic reaction?
Most common parasite in US?
Pinworms (Enterobius Vermicularis)
How are pinworms spread?
Spread by oral ingestion of eggs from anus
Most common symptom of pinworms?
Lifespan of pinworms?
Worms 3-4 the size of pinworms common in the tropics?
Whipworm (Trichuris trichura)
What can whipworm cause?
Local hyperemia and lesions of colonic mucosa
Hookworms (Necator amricanus/Ancylostoma duodenale)
Hookworms attach where?
Upper levels of small intestine
How is hookworm transmitted?
Infectious larvae, not eggs
Where do hookworm larvae penetrate?
How does dissemination of Ascaris, Hookworms, and Strongyloides work?
Ingestion of eggs -> Bloodstream -> Lungs -> Invasion of filariform larvae -> esophagus -> Adult in intestine
When hookworm penetrates skin what is left?
Small itchy papule where they penetrate skin
What can result from hookworm traveling through lung?
Most significant signs and symptoms from hookworm?
From ingestion of host blood
What does Strongyloides parallel in distribution and life cycle?
How does Strongyloide get in?
Filaria through skin
Important reservoirs for Strongy?
Cats and dogs
How does Strongy present?
Usually mild, but in immunosuppressed hyerinfection may result with severe pneumonitis and duodenitis
2nd most common parasite of humans?
Where are Ascaris usually living unattached?
Greatest danger of ascaris?
Abnormal migration in body to block biliary ducts/obstruction of small intestine
4 small intestinal parasites?
How does one get Trichinella spiralis?
Ingestion of improperly cooked pork
What do the larvae do in Trichinella?
Penetrate tissues, disseminate in blood, and encyst in muscle
In trichinella what do trapped larvae in the lungs cause?
Trichinella has what effect on heart?
Patchy interstitial myocarditis with eosinophilia and giant cells resulting in scarring and heart failure
Most effective treatment when dealing with larval migrans syndromes?
Corticosteroids and antihistamines to reduce inflammation
Cutaneous larval migrans known as?
Cutaneous larval migrans associated with?
Hookworms of dog and cat
Cutaneous larval migrans is occupational disease of who?
Plumbers, construction workers, duck hunters, and anyone exposed to infected soil
What is visceral larval migrans?
Infection of dog and cat ascaris with widespread and damaging dissemination of larvae throughout body
Who normally gets visceral larval migrans?
Puppies spread to children
What is known as neural larval migrans?
Who gets Balisascaris?
Children who eat dirt and have poor hygiene
Lymphatic filariasis (Wuchereria bancrofti) is transmitted by what?
Where do larvae develop of Lymphatic filariasis?
River blindness is caused by what?
What does Onchocerca volvulus cause?
Body lice and head lice cause what 3 disease?
1) Rickettsia prowazeki
2) Rochalimaea quintana
3) Borrellia recurrentis
Blue spots indicative of what?
Where do Chigger's take up residence?
What causes Chigger intense local inflammatory response?
Rhinosporidiosis causes what?
Granulomatous of mucous membranes resulting in polyp formation