Parasitology Flashcards
When naming organisms, the Genus should start with a _____ letter and species with a _____ letter
Genus: capital
Species: small
A symbiotic relationship in which 1 organism benefits from the other without causing any harm
Commensalism
Parasite that can multiply in fecal matter outside the body
Coprophilic parasite
Host in which parasite undergoes an arrested developmental stage
Paratenic host
Source of infection is known as the
Reservoir
Parasite that lays eggs which HATCH AFTER leaving a host
Oviparous
Parasite that lays eggs which HATCH BEFORE living a host
Ovoviviparous
Parasite that lays LARVA instead of egg
Viviparous
Parasitology slides and photographs are used for?
Quality control purposes
A clean, dry, waterproof container with a _____ lid is an appropriate collection container for a stool sample
Tight-fitting
CDC recommends that ___ or more samples, collected on separate days, be examined for O & P test
3
Beyond 1 hour, stool samples must be
Refrigerated
How long can fecal samples be stored in a refrigerator?
24 hours
Diarrheic stools must be examined within _____ to _____ after passage
30 minutes to 1 hour
Trophozoites are very fragile and could be DESTROYED at _____ temperature
Refrigerator
These interferes with identification of parasites, especially protozoan CYSTS
Mineral oil droplets
MERCURY CONTAINING fixative used to preserve parasite in stool specimen
Polyvinyl alcohol
Schaudinn’s fluid
Preservative to be employed with the trichrome stain
Polyvinyl alcohol
Stain recommended for intestinal coccidia
Modified-acid fast stain
Preservative in direct fecal smear
Formalin
Vector for Ascaris lumbricoides
Cockroach
Ascaris eggs without mammillary coating
Decorticated egg
This adult female roundworm migrates out of the anus and deposits eggs on perianal area
Enterobius vermicularis
Peripheral blood picture in Loeffler’s syndrome
Peripheral eosinophilia
Heart-to-Lung Migration
*ASH
Ascaris lumbricoides
Strongyloides stercoralis
Hookworm
Unholy three of roundworms
*HAT
Hookworm
Ascaris lumbricoides
Trichuris trichiuria
Severe itching / allergic reaction at the site of skin penetration by hookworm filariform larvae is called
Ground itch
Feeding stage of nematodes (hookworm, threadworm)
Rhabditiform larva
Infective stage of nematodes (hookworm, threadworm)
Filariform larva
Intestinal roundworm demonstrated as rhabditiform larvae in fecal specimen
Threadworm
Helminth that induces a microcytic, hypochromic anemia in its host
Hookworm
Rhabditiform larvae with SHORT buccal cavity and LARGE GENITAL primordium
Strongyloides stercoralis
Rhabditiform larvae with LONG buccal cavity and SHORT GENITAL primordium
Hookworm
Intestinal nematode capable of vertical transmission and congenital infections
Ancylostoma duodenale
Significant eosinophilia and muscle pain may occur after ingestion of meat infected with?
Trichinella spiralis
Agent of CUTANEOUS larva migrans or CREEPING eruption
Dog hookworm (A. caninum)
Agent of VISCERAL larva migrans
Toxocara canis and Toxocara cati
Pre-larval stage of filarial worms
Microfilaria
Most common identified species of filarial worms, sheathed, and nocturnal
Wuchereria bancrofti
Definitive host and reservoir of Wuchereria bancrofti
Humans
Filarial worm similar to W. bancrofti that may cause lymphadenopathy
Brugia malayi
Dracunculus infections cause ulcers that _____
On water contact, release larvae
Agent of river blindness
Onchocerca volvulus
Vector of Onchocerca volvulus
Black fly
Objective used to detect microfilariae
LPO
Scientific name of the head of a tapeworm
Scolex
Part of cestodes used for ATTACHMENT to the intestinal walls; “ANCHORING ORGAN” of cestodes
Scolex
When man becomes intermediate host for T. solium, this disease is manifested
Cysticercosis
Cestode capable of causing cysticercosis
Taenia solium
Humans serve as _____ host for T. solium
Definitive (or accidental intermediate)
Life span of T. solium
Up to 25 years
New species of Taenia discovered in Taiwan ; 3rd Taenia spp. ; Taiwan Taenia
Taenia asiatica
T. asiatica adult resembles T. saginata, but the _____ is close to T. solium
Cysticerci
Parasite that causes megaloblastic anemia
Diphyllobothrium latum
Lifespan of D. latum
25 years
Mistaken as adult Diphyllobothrium latum
Spirometra
Found in the intermediate host of Echinococcus granulosus
Hydatid cyst
Diagnostic stage of Echinococcus spp. in humans
Hydatid cyst
Used for sterilization when removing a hydatid cyst
Formalin
Definitive host for Echinococcus multilocularis
Foxes, coyotes, dogs
Fluke found in sheep and cattle
Fasciola hepatica
Fluke that causes vitamin B12 deficiency and intestinal obstruction
Fasciolopsis buski
Trematode that can cause cholangiocarcinoma
Clonorchis sinensis, Opisthorchis viverrini, Fasciola
Most flukes are hermaphroditic (have both sexes) except
Schistosoma (separate sexes)
Stage of schistosomes that goes out of the snail to go to water
Cercaria
Schistosoma spp. infects human by
Skin penetration
Katayama fever is associated with what parasite
Schistosomes
Swimmer’s itch or cercarial dermatitis is caused by
Cercaria of schistosomes
Habitat of Schistosoma japonicum inside human host
Superior mesenteric vein (small intestine)
Schistosome EGG recovered in URINE
Schistosoma haematobium
What is a Schistosomule
Cercaria minus tail
Operculated ovum seen in bloody sputum with CHARCOT-LEYDEN CRYSTALS
Paragonimus westermani
Adult P. westermani resides on what organ?
Lungs
How to prevent paragonimiasis?
Avoid eating raw freshwater crabs
Treatment for P. westermani infection
Praziquantel
Avoiding consumption of AQUATIC PLANTS is a way to prevent infection with
Fasciolopsis and Fasciola
Nonmotile, nonfeeding and infective stage of amebae
Cyst
Motile, reproducing and feeding stage of protozoa
Trophozoite
Objective used when viewing trichrome stained smear of protozoa
OIO
Color of trophozoite GLYCOGEN using trichrome stain
Colorless
Color of trophozoite NUCLEUS using trichrome stain
Red-purple
Color of CHARCOT-LEYDEN CRYSTAL using trichrome stain
Bright red
Color of CHROMATOID BODIES using trichrome stain
Bright to red
Pathogenic amoebic trophozoite that ingests RBCs of its host
Entamoeba histolytica
Point of differentiation between E. histolytica and E. hartmanni
Size
Mature cyst of E. histolytica has how many nuclei?
4
Mature cyst of E. coli has how many nuclei?
Up to 8
Trichuris trichiuria infection provides a good site for what protozoan?
Entamoeba histolytica
SREHP stands for
Serine-rich Entamoeba histolytica protein
Amoeba with a “GROUND GLASS” cytoplasm
Entamoeba histolytica / Entamoeba dispar
Sluggish, non-directional motility, has a “DIRTY CYTOPLASM”
Entamoeba coli
Amoeba with a characteristic “BASKET NUCLEUS”
Iodamoeba butschlii
Amoeba that contains INGESTED NEUTROPHILS
Entamoeba gingivalis
Amebae inhabiting the CNS enter the body through the
Nasal mucosa
DOUBLE-WALLED CYST with outer wrinkled wall and inner polygonal wall
Acanthamoeba spp.
Agent of primary amoebic meningoencephalitis (PAM)
Naegleria fowleri
Best staining procedures for Naegleria and Acanthamoeba
H & E
Wright stain
In what specimen are Acanthamoeba and Naegleria usually found?
CSF
Trophozoite with karyosomal chromatin appearing as ROSETTE of 4-6 granules
Naegleria fowleri
Protozoan often mistakes as cyst of amebae
Blastocystis hominis
The only ciliate pathogenic in humans
Balantidium coli
Associated with steatorrhea and GAY BOWEL SYNDROME
Giardia lamblia
Intestinal flagellate trophozoite with sucking disc, 2 nuclei, 8 flagella, and 1 axostyle
Giardia lamblia
The ONLY BILATERALLY SYMMETRICAL protozoan is
Giardia lamblia
Causes “CRYPT” hypertrophy in the duodenum and subsequently diarrhea
Giardia lamblia
Protozoan with an UNDULATING MEMBRANE
Trichomonas
Trypanosoma
What does D. fragilis have in common with T. vaginalis?
Neither has a cyst form
Specimen used for rapid diagnosis of T. vaginalis
Vaginal swab
Definitive host of Plasmodium spp.
Female Anopheles mosquito
Infective stage of malarial parasite to the VECTOR
Gametocyte
Infective stage of malarial parasite to HUMANS
Sporozoite
Principal vector of malaria in the Philippines?
Anopheles minimus flavirostris
Plasmodium spp. responsible for 90% of malaria cases
Plasmodium falciparum and Plasmodium vivax
Plasmodium spp. that may cause relapse of infection
Plasmodium vivax and Plasmodium ovale
HYPNOZOITES may be seen in malarial infection caused by
Plasmodium vivax and Plasmodium ovale
Paroxysmal cycle of Plasmodium knowlesi
24 hours
RBC inclusion produced by Plasmodium knowlesi
Sinton and Mulligan’s stipling
Type of blood specimen preferred for preparing blood smears for protozoan
Finger puncture
Stain of choice for diagnosis of malaria thick and thin smear
Giemsa stain
When performing thick and thin blood smears for malaria, which smear is FIXED?
Thin smear
Venipuncture blood is NOT recommended for
Malaria, Babesia and Hemoflagellates
To detect stippling, prepare blood films within _____ after being drawn
30 minutes to 1 hour
Type of microscope used for quantitative buffy coat method for malaria
Fluorescent
Oocyst of this parasite can be recovered in cat feces
Toxoplasma gondii
Patient with cerebral calcification must be tested with
Toxoplasma antibody titer
Important cause of chorioretinitis
Toxoplasma
Parasite that can undergo autofuorescence
Cyclospora
Specimen for detection of microsporidia
Fresh stool or formalin-fixed stool
Intracellular form of blood and tissue flagellates
Leishmanial
How is Trypanosoma cruzi trasmitted?
Bite of reduviid bug
Agent of GAMBIAN disease / “West African Sleeping Sickness”
Trypanosoma brucei gambiense
Agent of RHODESIAN disease / “East African sleeping sickness”
Trypanosoma brucei rhodesiense
Vector of African sleeping sickness
Glossina spp. (Tsetse fly)
Glossina palpalis, Glossina fuscipes, Glossina tachinoides are vector of
Trypanosoma brucei gambiense
Glossina morsitans, Glossina pallidipes, and Glossina swynnertoni are vectors of
Trypanosoma brucei rhodesiense
Agent of CHAGA’S DISEASE
Trypanosoma cruzi
Agent of KALA-AZAR / BLACK FEVER / Dumdum fever / Visceral Leishmaniasis
Leishmania donovani
Infective stage of Leishmania spp. to humans
Promastigote
This parasite has the following manifestation: WBCs with amastigotes inside
Leishmania
TRUE OF FALSE: Leishmania donovani, Histoplasma capsulatum, and Toxoplasma gondii are found WITHIN reticuloendothelial cells
True
Agent of “crabs”
Pthirus pubis (ectoparasite)
Scabies is a type of (infection or infestation)
Infestation
Also known as “head louse”
Pediculus humanus capitis
Wingless athropods
Ticks, bedbugs, mites, and spiders