Parasitology

"Cultures of parasites are different from bacterial cultures; no quality control is needed." This statement is: True, if the media are checked every 24 hours False, an organism and media controls need to be set up True, if two tubes of media are set up for each patient False, unless two different types of media are used

False, an organism and media controls need to be set up

Match the statement with the organism or organ: Hymenolepis diminuta anterior end for attachment of tapeworm by suckers or hooks Dipylidium caninum operculated egg with coracidium proglottid packets of eggs are characteristic Diphyllobothrium lantum segment formed distally from neck area of tapeworm scolex beetle is intermediate host

H. diminuta: beetle is intermediate host D. caninum: packets of eggs are characteristic proglottid: segment formed distally from neck area of tapeworm D. latum: operculated egg with coracidium scolex: anterior end for attachment of tapeworm by suckers or hooks

Sleeping sickness tsetse fly Malaria Anopheles bite Chagas' disease Triatoma feces Trichomonad vaginitis sexual intercourse Babesiosis tick bite Cutaneous leishmaniasis Phlebotomus bite Amebic dysentery ingestion

Sleeping sickness: tsetse fly Malaria: Anopheles bite Chagas' disease: Triatoma feces Trichomonad vaginitis: sexual intercourse Babesiosis: tick bite Cutaneous leishmaniasis: Phlebotomus bite Amebic dysentery: ingestion

The best specimen for studies of ova and parasites are those that are collected as: a. 3 normally passed specimens collected 2-3 days apart b. a 24 hour urine c. a pleural aspirate d. ear drainage

a. 3 normally passed specimens collected 2-3 days apart

Cysticercus is a stage in the life cycle of: a. Cestodes b. Trematodes c. Nematodes d. All of the above

a. Cestodes

This parasite has the following characteristics: stains red with acid fast stain, zoonotic transfer to humans, spread by fecal- oral route. The most likely organism is: a. Cryptosoridium b. Giardia c. Naegleria d. Nector

a. Cryptosoridium

This organism selectivly absorbs vitamin B 12 from host's intestinal tract. a. Diphyllobothrium latum egg b. Hymenolepis diminuta egg c. Echinococcus granulosus egg d. Taenia saginata egg

a. Diphyllobothrium latum egg

The most prevalent helminth to infect humans is: a. Enterobius vermicularis, the pinworm b. Ascaris lumbricoides,the large intestinal roundworm c. Taenia saginata,the beef tapeworm d. Schistosoma mansoni, one of the blood flukes

a. Enterobius vermicularis, the pinworm

Humans acquire infections with Diphyllobothrium lantum adult worms by: a. Ingestion if raw freshwater fish b. Skin penetration of cercariae c. Ingestion of freshwater crabs d. Ingestion of water chestnuts

a. Ingestion if raw freshwater fish

Individuals who lack the Duffy antigen on the surface of their red blood cells are protected against which species of Plasmodium? a. P. vivax b. P. falciparum c. P. malariae d. Pl ovale

a. P. vivax

The examination of sputum may be necessary to diagnose infection with: a. Paragonimus westermani b. Trichinella spiralis c. Wuchereria bancrofti d. Fasciola hepatica

a. Paragonimus westermani

This parasite has the following characteristics: banana shape gametocytes in RBC's, multiple ring forms in RBC's,all RBC's are infected. The identification of the parasite is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

a. Plasmodium falciparum

A 47-year-old male, who lives in Bangor, ME, returns from a trip to Southeast Asia. He visits his physician with fever, chills, headache, and malaise. His fevers seem to appear every 48 hours. A blood smear reveals the organism as seen in the image provided. Given this information, you would report the organism as a. Plasmodium vivax. b. P. ovale. c. P. malariae. d. Babesia microti.

a. Plasmodium vivax.

Which schistosoma species has a large terminal spine? a. Schistosoma haematobium b. schistosoma japonicum c. shistosoma mamsoni d. schistosoma mekongi

a. Schistosoma haematobium

Prior to his kidney transplant, a 56-year-old male is tested for ova and parasites. One of three stools submitted demonstrates the organisms seen in the image provided. You would identify the organisms as: (A.K.A threadwarm) a. Strongyloides stercoralis rhabditiform larvae. b. Hookworm spp. rhabditiform larvae. c. Hookworm spp. filariform larvae. d. Strongyloides stercoralis filariform larvae.

a. Strongyloides stercoralis rhabditiform larvae.

Eating poorly cooked pork can lead to an infection with: a. Taenia solium and Trichinella spiralis b. Taenia saginata and Hymenolepis nana c. Trichuris trichiura and Hymenolepis diminuta d. D. latum and A. lumbricoides

a. Taenia solium and Trichinella spiralis

Which of the following organisms may not require treatment if there is a light infestation? a. Trichuris trichiura b. Schistosoma mansoni c. Taenia solium d. Anisakis spp

a. Trichuris trichuria

Review the image provided. In the life cycle of this cestode organism, man serves as the ________________ host. a. definitive b. vector c. intermediate d. reservoir

a. definitive

Identify the following cestode: a. Hymenolepis nana egg b. Taenia saginata egg c. Diphyllobothrium latum egg d. Hymenolepis diminuta egg

a. hymenolepis nana egg

A physician suspects her patient has Paragonimus westermani based on the patient's physical and history. A stool sample is submitted for ova and parasite examination and is negative. You suggest the collection of a/an __________ specimen to assist with the diagnosis. a. sputum b. urine c. duodenal aspirate d. blood

a. sputum

A helminth egg is described as having terminal polar plugs. The most likely helminth is: a. Trichuris trichiura b. Fasciola hepatica c. Diphyllobothrium latum d. Hookworm

a. trichuris trichuria

How long does a person have to live after becoming infected with Naegleri fowleri ? a. twelve days b. seven days c. a year d. five days

a. twelve days

Identify the organism below: a. Ascaris lumbricoides fertilized egg b. Ascaris lumbricoides unfertilized egg c. Necator americanus egg d. Ascaris lumbricoides decorticated egg

b. Ascaris lumbricoides unfertilized egg

The only medically significant ciliate organism is: a. Acanthamoeba b. Balantidium coli c. Cryptosporidium parvum d. Chilomastix mesnili

b. Balantidium coli

The India ink stain is used as a presumptive test for the presence of which organism? a. Aspergillus niger in blood b. Cryptococcus neoformans in CSF c. Histoplasma capsulatum in CSF d. Candida albicans in blood or body fluids

b. Cryptococcus neoformans in CSF

A 20-year-old male with leukemia presents with watery diarrhea of two weeks duration, nausea, weight loss, and anorexia. A stool sample is submitted for routine culture and ova and parasite examination. The routine culture is negative for Salmonella, Shigella, Campylobacter, Yersinia enterocolitica, and shiga-toxin producing coli. The concentrated wet mount exam and trichrome stained stool smear are negative. Additional testing revealed the organism as seen in the image provided. Knowing the organism measures 9 μm, you would identify it as a. Cryptosporidium parvum. b. Cyclospora cayetanensis. c. microsporidia. d. yeast.

b. Cyclospora cayetanensis.

Do you know who I am? a. Echinococcus granulosus egg b. Diphyllobothrium latum egg c. Diphyllobothrium trophocyte d. Taenia saginata egg

b. Diphyllobothrium latum egg

The adult tapeworm of Echinoccoccus granulosus is found in the intestine of: a. Humans b. Dogs c. Sheep d. Cattle

b. Dogs

A patient is suspected of having amebic dysentery. Upon microscopic examination of a fresh fecal specimen for ova and parasites, the following data were obtained: a trophozoite of 25 um, progressive, unidrectional crawl, evenly distributed, peripheral chromatin, fine granular cytoplasm, up to 4 nuclei This information indicates the organism is: a. Entamoeba coli b. Entamoeba histolytica c. Endolimax nana d. Iodamoeba butschlii

b. Entamoeba histolytica

It is not necessary to examine the whole slide if eggs or cysts are noted within the first few fields examined. a. True b. False

b. False

The formalin-ethyl acetate concentration method is the most commonly used technique for concentrating fecal specimens. In this method the parasites float to the surface and the concentrate can e skimmed from the top of the tube. a. True b. False

b. False

The procedure that involves swabbing the child's perianal area with a tongue blade with cellopane tape is used for the detection of cryptosporidium eggs. a. True b. False

b. False

Eggs are passed in the feces of the definitive host;In water, the free-swimming miracidium hatches from the egg and penetrates a suitable snail intermediate host; After penetration of the snail, the miracidium undergoes developmental stages resulting in development of many cercaria;Cercaria exit the snail and swim until they contact aquatic vegetation and encyst, developing into metacercaria;Humans ingest the metacercaria on plants such as watercress; Metacercaria hatch & penetrate the intestinal wall and migrate through peritoneal cavity until coming in contact with liver.They penetrate the liver & migrate to bile ducts where they grow to adult worms. Rare in the USA, probably due to our diet not including the plants (wild grown) containing metacercariae. a. Fasciolopsis buski. b. Fasciola hepatica egg c. Clonorchis sinensis adult d. Paragonimus westermani adult

b. Fasciola hepatica egg

What protozoan parasite would you suspect if you saw the following in a fecal smear? A 15 um pear-shaped organism with eight flagella, a central axostyle, and two bilateral anterior nuclei containing large endosomes. a. Chilomastix mesnili b. Gardia lamblia c. Entamoeba coli d. Balantidium coli

b. Gardia lamblia

Humans can serve as both the intermediate and definitive host in infections caused by: a. Ascaris lunbricoides b. Hymenolepis nana c. Enterobius vermicularis d. Shistosoma japonicum

b. Hymenolepis nana

Human hookworm infections are acquired by: a. ingestion of ova b. Larval penetration of skin c. Ingestion of larvae d. ingestion of cysts

b. Larval penetration of skin

Primary amoebic encephalitis is caused by: a. Endolimax nana b. Naegleria fowleri c. Entamoeba coli d. Dientamoeba fragilis

b. Naegleria fowleri

Which larvae infects the host via penetration through the skin? (multiple answer-two organisms) a. Toxocara canis larva b. Necator americanus rhabditiform larva c. Trichuris trichiura d. Strongyloides stercoralis rhabditiform larva

b. Necator americanus rhabditiform larva d. Strongyloides stercoralis rhabditiform larva

Massive hemolysis, blackwater fever, and central nervous system involvement are most common with: a. Plasmodium vivax b. Plasmodium falciparum c. Plasmodium ovale d. Plasmodium malariae

b. Plasmodium falciparum

Clornorchis sinesis is commonly known as the: a. beef tapeworm b. chinese liver fluke c. sheep liver fluke d. hookworm

b. chinese liver fluke

Which insect vector spreads infection by the Loa Loa (eye worm) a. Tse Tse fly b. chrysops fly c. sand fly d. mosquito

b. chrysops fly

An operculated cestode egg that can be recovered from human feces is: a. Clonorchis sinensis b. Diphyllobothrium latum c. Paragonimus westermani d. Dipylidium caninum

b. diphyllobothrium latum

An astute hematologist notes the organism in the image provided on a stained blood smear. The microfilariae are sheathed. The anterior is rounded, the posterior tapers to a point. Infection occurs through the lymphatics. She calls you over to confirm its identification. She asks what disease is associated with this organism. You tell her a. Calabar swellings. b. elephantiasis. c. river blindness. d. visceral larval migrans.

b. elephantiasis

The organism depicted is a(n): a. amoeba b. flagellate c. filaria d. sporozoan

b. flagellate

The advantage of thick blood smears for malarial parasites is to: a. improve staining of the organisms b. improve detection of the organism c. remove RBC artifacts d. remove platelets

b. improve detection of the organism

Where do Plasmodium sporozoites proliferate? a. bone marrow b. liver c. red blood cells d. neucleated erythrocyte precursors

b. liver

Artifacts found in a stool specimen that can be confused with a ova or cysts are: a. Degenerated cells from the gastrointestinal mucosa b. pollen grains c. partially digested meat fibers d. dried chemical crystals

b. pollen grains

The diagnosis of Strongyloides stercoralis usually made by finding the _________form in the stool specimen. a. ovium b. rhabditiform larva c. filariform larva d. Trophozoite

b. rhabditiform larva

In a pediatric patient, the recommended clinical specimen for recovery of Enterobius vermicularis is the: a. Stool specimen b. Series of Scotch tape preparations c. Sigmoidoscopy scrapings d. Duodenal aspirates

b. series of scotch tape preparations

Trypansoma brucei gambiense is not endemic to the United States because the appropriate a. reservoir hosts do not exist. b. vector does not exist c. intermediate host does not exist d. sanitation practices are employed

b. vector does not exist

Fertilized, unfertilized, and decorticated eggs of ________ __________may be found in the stools of infected persons. a. Necator americanus b. Strongyloides stercoralis c. Ascaris lumbricoides d. Enterobius vermicularis

c. Ascaris lumbricoides

Embryonated eggs are ingested and hatch in the intestines and begin to migrate through the blood and lymphatic system. They finally reach the esophagus and once again enter the intestines, where the mature worm then begins to lay eggs. a. Ancylostoma duodenale egg b. Necator americanus egg c. Ascaris lumbricoides unfertilized egg d. Enterobius bermiularis egg

c. Ascaris lumbricoides unfertilized egg

The incorrect match between organism and the appropriate diagnostic procedure is: a. Onchocerca volvulus—examination of skin snips b. Cryptosporidium—modified acid-fast stain c. Echinococcus granulosus—routine ova and parasite examination d. Schistosoma haematobium—examination of urine sediment

c. Echinococcus granulosus—routine ova and parasite examination

Protozoan cysts are found in a wet mount of sediment from ethyl-acetate concentrated material. The cysts are without peripheral chromatin on the nuclear membrane. Each cyst has four nuclei and each nuclei has a large karyosome which appears as a refractive dot. These oval-shaped cysts are most likely: a. Chilomastix mesnili b. Entamoeba hartmanni c. Endolimax nana d. Entamoeba histolytica

c. Endolimax nana

What protozoan parasite would you suspect if you saw the following in a fecal smear? A 20 um round cyst with eight nuclei containing eccentric karyosome: a. Gardia lamblia b. Chilomastix mesnili c. Entamoeba coli d. Balantidium coli

c. Entamoeba coli

A Gram stain from a gum lesion showed what appeared to be amoebae. A trichrome smear showed amoebae with a single nucleus and partially digested PMNs. The correct identification is: a. Trichomonas tenax b. Entamoeba histolytica/E. dispar c. Entamoeba gingivalis d. Entamoeba polecki

c. Entamoeba gingivalis

Eggs are smooth, thick-shelled, football-shaped and flattened on one side: a. Trichuris trichiura b. Ancylostoma duodenale c. Enterobius vermicularis d. Ascaris lumbricoides

c. Enterobius vermicularis

The most pathogenic ameba in humans that causes amebic dysentery is: a. Giardia lamblia b. Balantidium coli c. Entmoeba histoytica d. Entamoeba coli

c. Entmoeba histoytica

Infections with the Taenia saginata tapeworm occurs when: a. Larvae invade the skin of the feet b. Eggs are ingested from contaminated food or water c. Larvae is ingested in the under cooked beef d. Larvae is ingested in the under cooked pork

c. Larvae is ingested in the under cooked beef

Which of the following microfilarial larvae is not diagnosed using peripheral blood? a. Loa loa b. Brugia malayi c. Onchocerca volvulus d. Wuchereria bancrofti

c. Onchocerca volvulus

The formalin-ether (ethyl acetate) concentration procedure for feces is used to demonstrate: a. Trophozoites b. Motility of helminth larvae c. Protozoan cysts and helminth eggs d. Formation of amoebic pseudopods

c. Protozoan cysts and helminth eggs

The egg of this fluke has a well developed large lateral spine: a. fasciola hepatica b. fasciolopsis buski c. Schistosoma mansoni d. schistosoma japonicum

c. Schistosoma mansoni

Which of the following statements is true regarding onchocerciasis? a. The microfilariae are in the blood during the late evening hours b. The parasite resides in the deep lymphatics c. The diagnostic test of choice is the skin snip d. The adult worm is present in the blood

c. The diagnostic test of choice is the skin snip

A 45-year-old hunter developed fever, myalgia, and periorbital edema. He has a history of pork and bear meat consumption. The larva is encysted in striated muscle. The most likely causative agent is: a. Hymenolepis nana b. Taenia solium c. Trichinella spiralis d. Toxoplasma gondii

c. Trichinella spiralis

Cysts of Iodamoeba bütschlii typically have: a. Chromatoidal bars with rounded ends b. heavily vacuolated cytoplasm c. a large glycogen vacuole d. Many ingested bacteria and yeast cells

c. a large glycogen vacuole

A parasite that is capable of infecting both man and animal increases its chances of survival. It is described as: a. an endoparasite b. symbiotic c. enzoonotic d. a facultative parasite

c. enzoonotic

Identify the picture below: a. Wuchereria bancrofti b. Loa loa c. fiber d. Tricurius tricuria adult

c. fiber

Polyvinyl alcohol used in the preparation of permanently stained smears of fecal material: a. concentrate eggs b. dissolves artifacts c. serves as an adhesive d. enhances stain penetration

c. serves as an adhesive

In a condition resulting from the accidental ingestion of eggs, the human becomes the intermediate rather than the definitive host. The correct answer is: a. Strongyloidiasis b. Ascariasis c. Trichinosis d. Cysticercosis

d. Cysticercosis

Which specimen is the least likely to provide recovery of Trichomonas vaginalis? a. Urine b. Urethral discharge c. Vaginal discharge d. Feces

d. Feces

Identify the following cyst: a. Isospora belli b. Endolimax nana c. Entamoeba coli d. Giardia lamblia

d. Giardia lamblia

Transmission is through ingestion of infected insects from flour contaminated by the droppings of infected rats. The organism is identified as: a. Hymenolepis nana egg b. Taenia saginata egg c. Diphyllobothrium latum egg d. Hymenolepis diminuta egg

d. Hymenolepis diminuta egg

A 12-year-old girl is brought to the emergency department with meningitis and a history of swimming in a warm-water spring. Motile amoebae that measure 10 μin size are seen in the CSF and are most likely: a. Iodamoeba bütschlii trophozoites b. Endolimax nana trophozoites c. Dientamoeba fragilis trophozoites d. Naegleria fowleri trophozoites

d. Naegleria fowleri trophozoites

Which of the following microfilarial larvae is not diagnosed using peripheral blood? a. Loa loa b. Wuchereria bancrofti c. Brugia malayi d. Onchocerca volvulus

d. Onchocerca volvulus

The presence of blood and pus in the urine is often associated with infection with: a. S. japonicum b. Trichomonas vaginalis c. Entamoeba Histolytica d. Schistosoma hematobium

d. Schistosoma hematobium

All of the following are examples of appropriate specimens for the recovery of fungi except: a. Tissue biopsy b. CSF c. Aspirate of exudate d. Swab

d. Swab

Identify the following organism: a. Diphyllobothrium latum egg b. Dipylidium caninum c. Echinococcus granulosus d. Taenia saginata/solium egg

d. Taenia saginata/solium egg

A stool specimen is submitted for ova and parasite examination. Which of the following organisms will not be recovered in this specimen type? a. Schistosoma japonicum b. Trichomonas hominis c. Balantidium coli d. Trichinella spiralis

d. Trichinella spiralis

Which of the following helminth is known as whipworm? a. Ascaris lumbricoides b. Strongyloides stercoralis c. Necator americanus d. Trichuris trichiura

d. Trichuris trichiura

How should you reduce your risk of Naegleri fowleri infection? a. Boil water b. Adequately chlorinate pools c. use nose plugs d. all of the above

d. all of the above

Trophozoites of the cyst shown above are likely to: a. contain red blood cells b. have clear, pointed pseudopodia c. contain few, if any, vacuoles d. have slow, undefined motility

d. have slow, undefined motility

A tapeworm segment is called a a. rostellum b. sucker c. stobila d. proglottid

d. proglottid

How is Trichomonas vaginalis transmitted? a. ingestion of cyst stage b. ingestion of trophozoite stage c. larval stage burrows through the skin d. sexual transmission

d. sexual transmission

Match each statement below with every tapeworm that is associated with that identifying statement. larva in raw pork Echinococcus granulosus ingestion of raw fish Taenia saginata dwarf tapeworm Diphyllobothrium latum beef tapeworm Hymenolepis nana adult tapeworm in dog Taenia solium

larva in raw pork: Taenia solium ingestion of raw fish: Diphyllobothrium latum dwarf tapeworm: Hymenolepis nana beef tapeworm: Taenia saginata adult tapeworm in dog: Echinococcus granulosus

mutullism the motile, susceptible actively multiplying form of the amoeba host causes no damage to host Zinc Sulfate living together symbiosis flotation method commensal organism where parasite lives Trophozoite benefits both organisms

mutullism: benefits both organisms host: organism where parasite lives Zinc Sulfate: flotation method symbiosis: living together commensal: causes no damage to host Trophozoite: the motile, susceptible actively multiplying form of the amoeba