Parasitology Flashcards
Entamoeba histolytica
10-20 um
infective/diagnostic stage = cyst
Troph: granular cytoplasm, *Evenly arranged chromatin in peripheral of nucleus), *Small compact central karyosome, May have ingested RBCs (Dysentery), unidirectional
Cyst: 4 nuclei, chromatoidal bar
Disease: invade mucosa, flask-shaped ulcer, ab.pain, frequent BMs
TX: metronidazole
Entamoeba hartmanni
5-10 um infective/diagnostic stage = cyst Troph: nondirectional, no RBCs ingested Cyst: up to 4 nuclei DIsease: non pathogenic TX: metronidazole
Entamoeba coli
20-40 um
infective/diagnostic stage = cyst
Trop: vacuoles w/ yeast, *eccentric karyosome, *clumped/irregular chromatin
Cyst: up to 8 nuclei, splinter-shaped chromatoidal bars
Disease: non pathogenic
TX: metronidazole
Endolimax nana
Infective/diagnosic stage = cyst Troph = *no peripheral chromatin, *large karyosome Cyst = 4 nuclei, no chromatoidal bars Disease: non pathogen TX: metronidazole
Blastocystis hominis
Infective/diagnostic stage = cyst
Cyst: large central body (stains dark), pushes nuclei to the edge
Disease: watery diarrhea, ab. pain, flatulence
TX: metronidazole
Iodamoeba butschlii
Infective/diagnostic stage = Cyst
Troph: active motility, granular cytoplasm with large vacuole, large/eccentric karyosome, “basket” appearance
Disease: non pathogenic
Dientamoeba fragilis
*NO cyst stage, amoeba-flagelate Troph: two nuclei, *fragmented karyosome, no peripheral chromatin, vacuoles with ingested debris Disease: diarrhea, ab. pain Related to bad hygiene TX: metronidazole
Acanthamoeba
Related to pools, water, AC units, contact lens hygiene
Pseudopods
Granulomatous Amoebic Encephalitis (GAE): headaches, neurological defects, keratitis/corneal ulcers, death
TX: Polymixin B, Clotrimazole
Naegleria fowleri
Related to water, pools, aquariums
Infective Stage = flagellate
Diagnostic Stage = Troph
Primary Amoebic Meningoencephalitis (PAM): Infection of meninges, enters through nasal cavity and migrate to brain via olfactory nerve, death by cardio-respiratory arrest
Diagnosis: CSF has decreased glucose/ increased protein, flagellate seen in CSF
Giardia lamblia
Intestinal flagellate
Infective Stage = Cyst (through food/water)
Diagnostic = Cyst AND troph
Cyst: 4 nuclei, median bodies
Troph: 4 pairs of flagella, adhesion disk, 2 nuclei, 2 axonemes, 2 median bodies
Disease: feeds on mucous in duodenum; ab. pain, flatulence, diarrhea with NO BLOOD
TX: Quinacrine (Atabrine)
Trichomonas vaginalis
No cyst stage
Troph: undulating membrane
Women: ab. pain, vaginitis, discharge
TX: metronidazole
Chilomastix mesnili
Infective Stage = Cyst
Cyst: lemon shaped with hyaline bleb, curved fibril (“shepard hook”)
Troph: pear shaped, 1 nucleus, oral groove
Disease: non pathogen
Balantidium coli
Ciliate Hogs are resevoir Infective/Diagnostic Stage = Cyst Troph: oval with short cilia TX: metronidazole, tetracycline
Plasmodium species
Definitive host = mosquito
Intermediate host = human
Infective stage = sporozoite
Diagnostic stage = ring form, gametocyte
Plasmodium falciparum
High parasitemia
Disease: Tertian Fever(48 hour), Fever spikes, decreased BP
Diagnosis: multiple rings, RBCs not enlarged, applique forms, banana-shaped gametocyte
Plasmodium malariae
Disease: Quartan Fever ( 72 hours)
Diagnosis: RBCs not enlarged, no multiple rings, “birds eye” rings, “band form” trophzoites, “rosette” schizont
Plasmodium vivax
Disease: Tertian Fever (48 hr)
Diagnosis: RBCs enlarged, Schuffner’s Dots present, large rings (>1/3 of cell), amoeboid trophs, schizonts have 8-12 merozoites
Plasmodium ovale
Disease: Tertian Fever (48 hour)
Diagnosis: RBCs enlarged, Schuffner’s Dots present, oval RBCs with fimbrated edge.
Babesia
B. microti = Northeast US
B. divergens = Europe
B. duncani = WA and CA
Diagnosis: High parasitemia, multiple ring forms per RBC, ring forms have clear center, “maltese cross”, extracellular ring forms
Life Cycle: Two hosts (tick and mouse), humans infected by Ixodes Tick
Toxoplasma gondii
Life Cycle: Cats are definitive hosts (humans infected by cats)
Disease: affects immunocompromised, flu-like, lymphadenopathy, congenital (can cause CNS problems in baby if they get it from their mother)
Cryptosporidium
Infective/Diagnostic stage = oocyst
Diagnosis: round oocysts, 3-6 um, pink/red on Modified Acid Fast Stain
Disease: diarrhea, dehydration, immunocompromised (AIDS)
Cystoiospora belli
Infective/Diagnostic stage = oocyst
Diagnosis: pink/red in Modified Acid Fast, can be seen in wet mount, 25-30 um
Disease: affects immunocompromised, non-bloody diarrhea, weight loss
Microsporidia
Tiny (0.8-4.0 um)
stain red/pink with trichrome blue stain, has a belt-like stripe
affects immunocompromised
Nematode
Round worms
TX: Albendazole. mebendazole
Enterobius vermicularis
“Pin worm”
Diagnosis: Pin worm paddle is best collected right after waking, humans are their only host
Disease: Ab. pain, pruritus
Infective/Diagnostic stage = egg
Life Cycle: female produces eggs and lays them around anus
Trichus trichura
“Whip Worm”
(Can co infect with Ascaris)
Infective/Diagnostic stage = embryonated (barrel) egg
Life Cycle: egg is ingested, larva mate and produce eggs, eggs found in cecum (large intestine)
Disease: diarrhea, gastrointestinal pain, rectal prolapse.
Egg = barrel shaped with polar plugs
Ascaris lumbricoides
“large intestinal roundworm”
Infective/Diagnostic stage = embryonated egg
Life Cycle: Ingest embyronated egg, lava hatch and circulate (can go to lungs, cough and swallow), mates in intestine, eggs passed
Diagnosis: Bumpy, thick walled egg with large cellular mass, largest nematode, spread through food/water
Disease: high worm burden can cause intestinal obstruction, pulmonary symptoms
Hookworms
Found in SMALL intestine
Ancyclostoma duodenale: Middle East, teeth for attachment
Necator americanus= North American, cutting plate
Infective stage = lavra
Diagnostic stage = egg and adult worm (can’t differentiate based on eggs)
Life Cycle: Larva penatrates skin, circulates (can go to lungs), mates/produces eggs, eggs passed
Disease: “ground itch”, blood loss
Strongyloides stercoralis
“Threadworm”
Infective/Diagnostic Stage: larva
Life Cycle: step on worm (penetrates skin), circulates (can go to lungs), female lays eggs in intestinal tract, EGGS HATCH IN GUT, larva passed, male/female mate outside of body, eggs hatch into larva, human steps on larva
Disease: cutaneous, pulmonary, intestinal
SHORT BUCCAL CAVITY IN RHABDITIFORM
Trichinella spiralis
“Trichinellosis”
Life Cycle: Ingest larva (animal), encysts in muscles, we eat the meat, female produces eggs in intestine, encysts in human muscles
Disease: myalgia, myocarditis, facial edema; must do muscle biopsy
Dracunculus medinensis
“Guinea Worm” (Africa)
Life Cycle: larva in water, ingested by copepods, human drinks water, larva mature in human, adult female migrates to feet/ankle, blisters form and release female, female lays eggs in water
TX: pull it out
Cestodes
Tape worms
TX: Praziquantel
Definitive host = humans
Taenia solium
“pork tape worm”
can have brain cysticercus
Life Cycle: cysticercus ingested from raw pork, attach to intestine and release gravid proglottids, eggs hatch and pass, pigs eat eggs
Can not differentiate based on eggs
scolex is rostellum with ring of hooklets
Taenia sanguinata
“beef tapeworm”
raw beef
NO brain cysticercus
scolex is flat/rounded
Diphyllobothrium latum
“broad fish tapeworm”
raw fish
Infective stage = Pleroceroid (in fish muscle)
Diagnostic stage = egg
life cycle: pleroceroid is in fish muscle, we eat fish, grows in intestinal tract, egg goes into water, embryo hatches in water, enters crustation, fish eats crustation, we eat fish
Disease: Gefilte Fish “Jewish Housewife Disease”, egg has operculum WITHOUT shoulders with abopercular knob
Diagnosis: diarrhea, vomit
proglottids are broader than long
Hymenolepsis nana
“dwarf tape worm”
Infective/Diagnostic stage = egg
Life Cycle: egg ingested by insect, rodent eats insect, humans ingest/inhale eggs
Disease: light, ab. pain, diarrhea
Diagnosis: 6-hooked embryo with POLAR FILAMENTS
Hymenolepsis diminuta
“rat tape worm”
Same as D. nana, but egg has NO polar filiments
Trematodes
Flukes TX: Praziquantal Infective stage = larva Diagnostic stage = egg Life Cycle: Human stands in water, cercaria (larva) attaches to skin and burrows in, circulates (bladder/gut), eggs passed in stool, eggs goes into water, ingested by snail, burrows out of snail and into water
Shistosoma
“swimmers itch”
Mansoni = South America, Africa, Middle East ; lateral spine
Japonicum = China, Japan ; small/less conspicuous spine
Haematobium = Africa; large/straight spine
Paragonimus westermani
“lung fluke”
Infective stage = larva
Diagnostic stage = egg
Life Cycle: humans eats crustation, ingests larva (cercaria), develops in gut, passes, hatches in water, enters snail, crustation eats snail
Diagnosis: egg has operculum with SHOULDERS
Fasciolopsis bucki
"large intestinal fluke" Watercress, water chestnuts SMALL INTESTINE Diagnostic stage = egg Small/indistinct operculum
Fasciola hepatica
“Sheep live fluke”
Life Cycle: Humans eat watercress, parasite grows in liver/gall bladder, eggs oass, miracidium enters snail, becomes cercaria, enters plant
Found in liver, can obstruct liver ducts
Disease: URQ pain, high IgG/IgM, jaundice, biliary obstruction, hepatomegaly
Can not speciate based on eggs, so look at where the adult is located.
Clonorchis sinensis
“Chinese/Oriental Live Fluke”
Life Cycle: We pass egg, it hates and lives in snail, fish eat cercaria, we eat fish
Diagnosis: “urn shaped” eggs, operculum WITH SHOULDERS, knob at opposite end.
