Introduction to Parasites (Habal) Flashcards by christine lurie

Neurocysticercosis - Taenia solium

How well did you know this?

Not at all

Perfectly

This parasite is more common in male homosexuals and poorly sanitized environments, is prevalent in the tropics, and is obtained through fecal-oral transmission.

Entamoeba histolytica

How well did you know this?

Not at all

Perfectly

The species of Trypanosoma is found in the Americas, mainly central and South, emphasis on South.

T. cruzi

How well did you know this?

Not at all

Perfectly

Echinococcus granulosus

How well did you know this?

Not at all

Perfectly

This form of Leishmania is the most common. It causes relatively benign self-healing lesions. What is it and how would you treat it?

Cutaneous Leishmaniasis

Sodium stibogluconate

How well did you know this?

Not at all

Perfectly

Ascaris lumbricoides

How well did you know this?

Not at all

Perfectly

This parasite is common in tropical countries. It causes infection through ingestion or larval penetration of skin. Diagnosis is of larva in stool. Clinical manifestiations include itching, wheezing (pneumonia), diarrhea, weight loss.

Strongyloides strocrailis

How well did you know this?

Not at all

Perfectly

Romana’s sign - T. cruzi

How well did you know this?

Not at all

Perfectly

This parasite is found world-wide in lakes, streams, etc. Risk factors for infection via fecal-oral transmission include contact with domestic and wild animals, camping, and places such as prisons, day cares, and mental health institutions.

Giardia lamblia

How well did you know this?

Not at all

Perfectly

Ring-enhancing lesions on brain caused by Toxoplasma gondii

How well did you know this?

Not at all

Perfectly

This type of parasite can reproduce in high numbers, leading to many organisms that can obstruct parts of the body, leading to clinical manifestations.

Roundworms - nematodes

How well did you know this?

Not at all

Perfectly

T. bruci - enlarged lymph node (Winterbottom’s sign)

How well did you know this?

Not at all

Perfectly

Found in sub-Saharan Africa and transmitted by the Tse Tse fly, this parasite causes local inflammation at the site of infection, including swollen lymph nodes. It can cross the blood brain barrier, resulting in CNS involvement that manifests in symptoms such as somnolence and confusion. What is the available treatment for this?

T. bruci

Suramin

How well did you know this?

Not at all

Perfectly

Taenia saginata

How well did you know this?

Not at all

Perfectly

Adult worm appears yellow with dark markings and grow anywhere from 3-15 m in length. Scolex has 2 sucking grooves. Crustaceans eat eggs found in fresh water. Humans eat these crustaceans, ingesting the eggs, which then become larvae, and then adults which can then lay eggs. Definitive hosts are humans and dogs. Transmission is ingestion of raw, undercooked fish.

Diphyllobothrium latum - fish tapeworm

How well did you know this?

Not at all

Perfectly

This protozoa of the Apicomplexa superphylum is a zoonotic, opportunistic parasite. Its definitive host is the domestic cat; vertebrates are the intermediate host. Immunocompromised individuals are at a greater risk of infection, as is the fetus if the mother acquires the infection during gestation.

Toxoplasma gondii

How well did you know this?

Not at all

Perfectly

Life cycle of this parasite always includes at least one intermediate host that is a snail.

Trematodes

How well did you know this?

Not at all

Perfectly

45 y/o immigrant from Mexico presents with hydrocephalus, motor spasms, paraplegia, loss of vision. He has a history of chronic meningitis. X-Ray shows many holes in brain. What’s wrong with him?

Neurocysticercosis - caused by Taenia solium

How well did you know this?

Not at all

Perfectly

This parasite causes infection from soil contaminated with human feces. The adult worm inhabits the cecum and large intestine. Light infections are asymptomatic while heavy infetions cause tenesmus, malnutrition, and diarrhea. In severe cases, you may encounter rectal prolapse.

Trichuris trichiura - whipworm

How well did you know this?

Not at all

Perfectly

This species of helminths has a segmented plane, is hermaphroditic, and has an oral sucker, botridias, and double Rostellar hooks.

Cestodes

How well did you know this?

Not at all

Perfectly

This species of helminths has an unsegmented plane, has a digestive tube that ends in the cecum, is hermaphroditic (except for Schistosoma, which are dioecious), and has both oral and ventral suckers.

Trematodes

How well did you know this?

Not at all

Perfectly

Strongyloides strocrailis

How well did you know this?

Not at all

Perfectly

This parasite, which is transmitted by the Reduviid kissing bug, is found in rural and poor areas of Central and South America. Upon infection, the parasite invades macrophages, creating a chagoma.

T. cruzi

How well did you know this?

Not at all

Perfectly

This parasite is transmitted by the sand fly and reproduces inside macrophages.

Leishmania

How well did you know this?

Not at all

Perfectly

What are the 6 species of Leishmania?

L. donovani L. tropica L. major L. aethiopica L. mexicana L. brazilliensis

Echinococcus granulosus

This is the most common tapeworm in the US. It is the only human tapeworm to complete its cycle in one host; both larval and adult forms can be found in man. It can be directly transmitted through ingestion of eggs that hatch in the duodenum or indirectly transmitted through ingestion of infected arthropods. What is it and how would you treat it?

Hymenolepsis nana Praziqantel

This is one of the largest and most common nematodes in the world. Infection is from soil contaminated with human feces and often occurs when parasite eggs are ingested in undercooked meat. Females produce about 200,000 eggs daily, causing the massive amount of worms that can grow and cause bodily obstructions.

Ascaris lumbricoides

This parasite only infects humans. Male and female worms inhabit the colon; female worms migrate to perianal region at night to lay eggs. Diagnosis is made using the scotch tape test. What it this and how would you treat it?

Enterobius vermicularis - pinworm Albendazole Hand washing

This single-celled protozoa that uses flagella to move uses humans and animals as a reservoir and leaves cysts, which can survive in water up to 3 months, in their feces. Symptoms include watery, foul smelling diarrhea, nausea, and weight loss. It is often associated with areas of chronic conditions and stagnant or slowly-moving water that has been contaminated by animal feces.

Giardia lamblia

Using a string test, you identify in your patient a parasite that is known for its pear-shaped trophozoite with 2 prominent nuclei, a ventral sucking disk, and 4 pairs of flagella. Its cyst, which is the infective stage, has 4 nuclei and is passed through the stool. What is this parasite, and what treatment would you choose?

Giardia lamblia Metronidazole

This parasite causes infection via ingestion of raw or undercooked pork. It has a scolex with 4 suckers and a circle of hooklets. Humans can serve as definitive or intermediate hosts.

Pork tapeworm - Taenia solium

Also, what is the distinguishing feature of this organism?

Trypanosoma (Trypomastigote) Kinetoplast - DNA inside the mitochondria

This parasite is found in dogs (definitive host) and sheep; hunters and sheppards are most at risk. It has a scolex with 3 proglottids, a rostulum, 4 suckers, and 2 rows of hooks. It is one of the smallest tapeworms, and it sheds proglottids in feces.

Echinococcus granulosus - dog tapeworm

Infection by this parasite is associated with ingestion of cysts in undercooked pork or bear meat. Diagnosis is made via encysted larva in striated muscle. Clinical manifestations include gastroenteritis, fever, muscle pain, periorbital edema, and eosinophilia.

Trichinella spiralis

This parasite, caused by fecal-oral or food and waterborne transmission, causes chronic, self-limiting non-bloody diarrhea in immunocompetent individuals, but may last as long as 4 months in HIV patients or cause focal neurological deficits, retinochoroiditis, or pnumonia in the immunodeficient patient. Affected newborns may have hydrocephalus, hepatosplenomegaly, jaundice, fever, anemia, and/or pneumonia.

Toxoplasma gondii

This form of Leishmania cuases simple skin lesions that metastzsize to mucosae, especially in the nose and mouth regions. What is it and how would you treat it?

Mucocutaneous Leishmaniasis Sodium stibogluconate

Trypanosoma cruzi

The organism in which the parasite develops is called the?

Intermediate host

This parasite causes infection due to ingestion of raw saltwater seafood. Symptoms include gastroenteritis, eosinophilia, and presence of occult blood in stool.

Anisakis

The non-motile, membrane-protected form of protozoa that is in the infective stage is called the?

Cyst

Entamoeba histolytica trophozoite

Patient presents with hydatid cysts in the liver that you're worried may travel to the brain. Patient is mostly asymptomatic, but knowing what this organism could be you worry about leakage or rupture of these cysts that could result in anaphylactic reaction (fever, hypotension). What is this parasite?

Echinococcus granulosus

Pathogenesis of this parasite is as follows: Ingestion of food/water contaminated with eggs - eggs hatch in small intestine - released juvenile larvae penetrate intestinal wall and get into portal circulation - larvae are carried to liver, heart, then lungs - larvae migrate through lungs to trachea - larvae are coughed up then swallowed back down to the intestine - larvae mature, mate, and complete cycle.

Ascaris lumbricoides

Describe what you might find in the cells of Entamoeba histolytica.

Trophozoites - single nucleus, ingested RBCs Cyst - 4 nuclei (in stool)

This parasite is common in Africa and Central America. It is transmitted by the Black Fly. Clinical manifestations include subcutaneous inflammation and pruritus. If microfiliearage migrate to the eyes, they can cause "River Blindness." What is this and what would you treat it with?

Onchocerca volvulus Ivermectin

What are 2 filarila nematodes we discussed? What are they notorious for doing?

Wuchereria bancrofti & Onchocerca volvulus Invade lymph, causing blockage of lymphatics

Ancyclostoma

The oocytes of this parasite are shed by its definititve host, the domestic cat. Exposure to cat feces, such as when cleaning the litter box, can lead to infection, which can be extremly harmful if caught by a pregnant woman as this parasite can cross the placenta.

Toxoplasma gondii

This species of Leishmania causes "Kala-Azar" fever - skin, lymph, bone marrow, spleen, and liver involvement. It causes a generalized infection of the reticuloendothelial system, hepatosplenomegaly, and has a high mortality. Which species is it and how would you treat it?

Visceral leishmaniasis Sodium stibogluconate

The living carrier that transports the parasite from infected to non-infected host is called the?

Vector

This gastrointestinal protozoa is associated with diarrhea in the immunocompromised and fecal-oral transmission. Extremely low exposure to its oocytes via a source such as contaminated water supply will cause mild, self-limiting enterocolitis in the immunocompetent patient and extreme diarrhea and dehydration in the immunocompromised, particularly in AIDS patients. What treatment would you suggest?

Cryptosporidium parvum There is no effective therapy; often lethal in AIDS patients

Patient presents with dilated cardiomyopathy, but no other acute symptoms. What parasite could be responsible for this? What fungus? What would you treat the parasite with?

T. cruzi Coxsackie B Nifurtimox

Female Anopheles mosquito transmits larva of this parasite most commonly in the tropics. Clinical manifestations include filarisasis and elephantiasis.

Wuchereria bancrofti

The metabolically active, usually motile stage of protozoa is called the?

Trophozoit

The host in which the mature or sexually mature parasite lives is called the?

Definitive host

Although most patients are asymptomatic, you may see abdominal dicomfort and cramping, as well as diarrhea and constipation cycles. Patients may also present with B12 deficiencies due to decreased uptake, which may then result in megaloblastic anemia. What parasite is this and how would you treat it?

Diphyllobothrium latum Praziquantel, avoid undercooked fish, freezing fish

Life cycle of this parasite: Human ingests fish infected by metacercaria - these excyst and develop into adults - adult gives eggs that when shed in human can form mericidia - these are taken up by a snail - leave snail as cercariae are free-swimming in water - finds sheep and encysts to form metacercaria (infective when ingested) - human ingests sheep, gets sick

Fasciola hepatica - sheep liver fluke

Enterobius vermicularis

Patient presents with flask-shaped ulcer, watery stools containing mucus and blood, and complaint of gradual onset of abdominal pain. You're concerned that this ulcer may be deep enough to hit the blood supply of the intestinal wall, which would would allow the organism to disseminate into other organs and, potentially, the CSF. What does he have? What will you treat him with?

Entamoeba histolytica Metronidazole

Taenia solium

Patient presents with megacolon and megaesophagus. No acute symptoms currently What parasite can cause this to occur?

T. cruzi

Entaboeba histolytica, Giardia lamblia, Cryptosporidium parvum, Trichomonas vaginalis, Microsporidia, Apicomplexa, Trypanosoma, Leishmania are all examples of what kind of protozoa?

Intestinal and tissue

This parasite's trophozoites coat the distal villi, leading to malabsorption of food. Patients who are IgA deficient are predisposed to symptomatic infection.

Giardia lamblia

These types of parasites have a characteristic leaf-like appearance, ventral sucker, and oral opening. All are associated with free-swimming.

Trematodes - flukes

Entamoeba mature cyst

Life cycle of this parasite: Human ingests fish infected by metacercaria - these excyst and develop into adults - adult gives eggs that when shed in human can form mericidia - these are taken up by a snail - leave snail as cercariae are free-swimming in water - finds fish and encysts to form metacercaria (infective when ingested) - human ingests fish, gets sick

Clonocrichis sinensis - Chinese liver fluke

Trypanosoma bruci

What do Taenia solium have that makes them particularly dangerous?

Cysticerosis stage - embryos can travel throughout body and then form a cyst. Symptoms will depend on where that cyst ends up. If it makes it to the brain, you'll get neurocysticercosis - this is bad!

Name the phylum with the following characteristics: unicellular, aerobic, heterotrophic, present in areas with large water supply, asexual reproduction (via budding, schizogony, sexual means), and presence of cyst under adverse conditions.

Protozoa

Characteristics of this type of cestode include scolex (head), segmented body (proglottids), suckers, monocieous, and eosionphilia (increase IL-5).

Tapeworms

This parasite has larva that can penetrate skin. It attaches to the GI mucosa, causing blood and fluid loss. Clinically, it can manifest as microcytic hypochromic iron deficiency anemia, pot belly, finger clubbing, and pica. How would you treat it?

Ancyclostoma duodenale - hookworm Albendazole

This parasite is most encountered in Asia, but has been found in other places around the world. Egg has a characteristic operculum. Adults are encapsulated in a granuloma, which can lead to what appear to be clinical manifestations of TB. Ruptured cysts produce cough and chest pain.

Paragonimus westermani

This parasite is found world-wide. It has a scolex with 4 suckers, but no hooks. Infection occurs by ingestion of cystceri in undercooked beef. Humans act as the host. What parasite is this and how would you treat it?

Beef tapeworm - Taenia saginata Praziquantel, Albendazole

Life cycle: Unembryonated eggs in water - embryonated eggs - miracidia hatch and penetrate snail - sporocytes, rediae, cerccariae - cercariae invade the crustacean and encyst into metacercariae - humans ingest inadequately cooked or pickled crustaceans containing metacercariae - excyst in duodenum - adults in cystic cavities in lungs lay eggs which are excreted in sputum; alternately eggs are swallowed and passed with stool

Paragonimus westermani

Ascaris lumbricoides

This species of helminths is cylindrical, has a body cavity, has a digestive tube that ends in the anus, is doecious, and has lips, teeth, filariform extremities, and dentary plates.

Nematodes

This species of Trypanosoma is found in Africa.

S. bruci

Entamoeba histolytica trophozoite

Patient presents with hemorrhagic/eosinophilic pneumonia, intestinal rupture, asthma, and urticaria. What parasite has infected the patient and how would you treat it?

Ascaris lumbricoides Albendazole

This parasite is common world-wide, especially in warm, humid climates. It is characterized by a curved anterior end and a mouth containing large plates that can cut through intestinal wall.

Ancyclostoma

This parasite is a pathogenic amoeba that leads to invasive amoebiasis. Psuedopods allow it to move, and the contaminated water causes diarrhea in infected persons.

Entamoeba histolytica

Introduction to Parasites (Habal) Flashcards

(82 cards)