[mtle] micropara reinforcements pt. 2

30 minutes

LIQUID stool sample can be examined for ova and parasites within how many mins?

1 hour

SEMI-SOLID stool sample can be examined for ova and parasites within how many mins?

24 hours

FORMED stool sample can be examined for ova and parasitse within how many mins?

b. trophozoites

In collection and transport of stool specimens for parasites, which parasitic stage is most affected by length of time from collection to examination?

a. cysts

b. trophozoites

c. oocysts

d. helminth larvae

Entamoeba histolytica

amoeba causing ACUTE AMOEBIC DYSENTERY, EXTRAINTESTINAL INFECTION, "FLASK-shaped" lesion

cyst: CENTRAL karyosome with EVEN peripheral chromatin; trophozoite: INGESTED RBCs

infective stage: cyst

diagnostic stage: cyst and trophozoite (stool), trophozoite (extraintestinal)

Blastocystis hominis

amoeba that is sometimes pathogenic; VACUOLATED, AMOEBA-like with granular and cyst forms

infective stage: cyst

diganostin stage: ALL forms

Naegleria fowleri

amoeba causing PRIMARY AMOEBIC MENINGOENCEPHALITIS; has FLAGELLATE form with SUCKER-like structures

infective stage: trophozoite

diagnostic stage: trophozoite

Acanthamoeba spp.

amoeba causing GRANULOMATOUS AMOEBIC MENINGOENCEPHALITIS; NO flagellate form; has SPINE-like pseudopods

infective stage: trophozoite

diagnostic stage: trophozoite and cyst

Giardia lamblia

flagellate causing TRAVELER'S DIARRHEA STEATORRHEA; PEAR-shaped with TWO ventral sucking disks

infective stage: cyst

diagnostic stage: cyst or trophozoite

habitat: small intestine

Dientamoeba fragilis

flagellate causing CONCOMITANT infection with PINWORM or ASCARIS infection; AMOEBOID; NO cyst stage

infective stage: trophozoite

diagnostic stage: trophozoite

"falling leaf" motility

G. lamblie will produce what motility?

hakansson phenomenon

featude diagnostic for identification of D. fragilis; numerous cytoplasmic granules exhibit Brownian movement.

Trichomonas fragilis

flagellate causing TRICHOMONIASIS; has UNDULATING membrane that is HALF of its body; NO cyst stage

infective stage: trophozoite

diagnostic stage: trophozoite

jerky, twitching motility

T. fragilis will produce what motility?

Leishmania spp.

flagellates causing LEISHMANIASIS

vector: sandflies: Phlebotomus (old world), Lutzomyia (new world)

developmental stage: amastigote, promastigote

infective stage: promastigote

diagnostic stage: amastigote

Trypanosoma brucei complex

flagellates causing AFRICAN SLEEPING SICKNESS

vector: tsetse flies (salivarian)

developmental stage: epimastigote, trypomastigot

infective or diagnostic stage: trypomastigote

Trypanosma cruzi

flagellate causing CHAGAS disease

vector: reduviid bug (stercorarian)

developmental stage: ALL stage

infective stage: trypomastigote

diagnostic stage: trypomastigot, amastigote

c. visceral leishmaniasis

32-year old male peace corps volunteer recently returned from 2-year period working in war zone in southern Sudan in Central Africa. he presents with marked SPLENIC ENLARGEMENT, NONspecific HYPERGAMMAGLOBULINEMIA, and NEGATIVE leishmanin skin test (montenegro reaction). mild fevers occur irregularly. most likely parasitic disease is?

a. malaria

b. cutaneous leishmaniasis

c. visceral leishmaniasis

d. trypanosomiasis

e. filariasis

Balantidium coli

LARGEST protozoan; main reservoir is PIGS causing WIDE MOUTHED ULCERS; NO extraintestinal spread

infective stage: cyst

diagnostic stage: cyst and trophozoite

Cytoisospora belli

intestinal coccidians causing DIARRHEA in immunocompromised; ACID-FAST coccidian

Cryptosporidium parvum

intestinal coccidia causing DIARRHEA, MALABSORPTION, EXTRAintestinal infection; important OPPORTUNISTIC infection in AIDS patients; ACID-FAST stain; RESISTANT to chlorination levels in drinking water

d. mosquito bite

Cryptosporidium parvum can be transmitted through all of the following, except

a. contaminated foo, water, raw milk

b. oral-anal sexual contact

c. zoonotic and direct contact

d. mosquito bite

Cyclospora cayetanensis

intestinal coccidia causing PROLONGED DIARRHEA; exhibit BRIGHT BLUE autofluorescence (365 nm) and MINT GREEN autofluorescence (450-490 nm)

(1) Plasmodium falciparum

(1) parasite causing MALIGNANT TERTIAN malaria (36-48 hrs) infecting ALL ages of RBCs; RECRUDESCENCE; CNS involvement is very common; also caus SEVERE ANEMIA with BLACKWATER URINE

(2) Plasmodium falciparum

(2) malarial parasite

ring forms: ring with TWO CHROMATIN DOTS; APPLIQUE forms present

trophozoite: small COMPACT ring with cytoplasmic VACUOLATION

schizont: NEARLY fills RBC

gametocyte: crescent, sausage, banana-shaped

maurer's dot

inclusions seen in P. falciparum

(1) Plasmodium vivax

(1) parasite causing BENIGN TERTIAN MALARIA (48 hrs) infecting YOUNG RBCs; TRUE RELAPSE; may persist in EXOERYTHROCYTIC CYCLE through hypnozoites; may cause SPLENOMEGALY

(2) Plasmodium vivax

(2) malarial parasite

ring form: occupies 1/3 of RBC; ring with ONE or TWO CHROMATIN DOTS

trophozoite: AMOEBOID form

schizont: FILLS RBCs

gametocyte: round or oval

schuffner's dots

inclusions seen in P. vivax

(1) Plasmodium malariae

(1) parasite causing QUARTAN malaria (72 hrs) infecting OLD RBCs; RECRUDESCNECE; COMMONLY associated with NEPHROTIC SYNDROME [!!]

(2) Plasmodium malariae

(2) malarial parasite

ring form: COMPACT RING with HEAVY chromatin dot

trophozoite: BAND-shaped

schizont: ROSETTE (DAISY HEAD appearance)

gametocyte: round or oval

ziemann's stippling

inclusions of P. malariae

(1) Plasmodium ovale

(1) parasite causing TERTIAN malaria (48 hr) infecting YOUNG RBCs; TRUE RELAPSE; may persist in EXOERYTHROCYTIC cycle by hypnozoite

(2) Plasmodium ovale

(2) malarial parasite

ring form: DENSE ring with DENSE chromatin mass

trophozoite: COMPACT RING-shaped body inside RAGGED RBC

schizont: fill 3/4 of RBC; appear in IRREGULAR clusters

gametocyte: ROUND or OVAL

jame's or schuffner's dots

inclusions of P. ovale

(1) Plasmodium knowlesi

(1) parasite causing QUOTIDIAN malaria (24-27 hrs) infecting ALL RBCs; RECRUDESCENCE; can be as dangerous as P. falciparum

(2) Plasmodium knowlesi

(2) malarial parasite

ring form: resembles P. falciparum (TWO chromatin dots with APPLIQUE forms)

trophozoite: BAND-shaped

schizont: DISTORTED and FIMBRIATED RBCs; GRAPE-like; NO rosettes

gametocytes: round or oval

stinton and mulligan's

inclusions of P. knowlesi

true relapse

type of recurrence; REACTIVATION of HYPNOZOITES in liver and subsequent erythrocytic schizogony

recrudescence

type of recurrence; occur when erythrocytic parasites become numerous after period of LOW parasite density which arise from schizonts that persist and are sequestered in SPLEEN

Fy (a-b-)

Duffy phenotype causing RESISTANCE to P. vivax [!!]

sickle cell, G6PD deficiency

disorders causing RESISTANCE to P. falciparum [!!]

c. ring and gametocyte

which developmental stages of P. falciparum is seen in peripheral blood smear?

a. ring, trophozoite, and schizont

b. ring and trophozoite

c. ring and gametocyte

d. all stages

a. ring, trophozoite, and schizont

which developmental stages of P. malariae is seen in peripheral blood smear?

a. ring, trophozoite, and schizont

b. ring and trophozoite

c. ring and gametocyte

d. all stages

d. all stages

which developmental stages of P. vivax, P. ovale, P. knowlesi is seen in peripheral blood smear?

a. ring, trophozoite, and schizont

b. ring and trophozoite

c. ring and gametocyte

d. all stages

b. gametocyte

what developmental stage of Plasmodium spp. is ingested by Anopheles mosquito?

a. ring form

b. gametocyte

c. trophozoite

d. schizont

thin smears

-malarial smear; prepare peripheral blood smear at one end of slife; stain with GIEMSA (after fixing; PREFERRED) or WRIGHT STAIN (NO fix needed; alcohol based); examine under OIO for LEISHMANIA, MICROFILARIAE, MALARIAL PARASITE, TRYPANOSOME

-use to IDENTIFY organism

thick smear

-malarial smear prepared by dropping blood on other end until smear is size of NICKEL and about 10 cells thick, let dry overnight, LAKE CELLS (destroy red cells) on this part of slide (immersing buffer or directly into stain)

-used to SEARCH for organism

giemsa stain

stain with WATER base (THIN but not thick smears must be FIXED in alcohol before staining)

wright stain

stain with ALCOHOL base (THICK but not thin smears must be LAKED before STAINING BOTH smears without fixing)

a. Giemsa stain

what is the preferred stain for malarial smear?

a. Giemsa

b. Wright

c. Eosin

d. Methylene blue

a. thin smear should be fixed prior to staining with Giemsa

which of the following is true about preparation of malarial smears?

a. thin smear should be fixed prior to staining with Giemsa

b. thin smear should be laked prior to staining

c. RBCs in thick smears should not be allowed to lyse

d. RBCs in thin smears should be allowed to lyse

Babesia spp.

parasite infecting animals causing TEXAS CATTLE FEVER or RED WATER FEVER; transmitted by TICK BITES (Ixodes) or through blood transfusion (uninfected host must be in conctat with tick's saliva for 12 hrs or longer before parasite can be transmitted)

Babesia spp. (trophozoite)

form of Babesia spp. resembling P. FALCIPARUM RING FORMS but does NOT contain inclusions or pigments

Babesia spp. (merozoite)

form of Babesia spp. resembling 4 TROPHOZOITES attached by respective CHROMATIN DOTS inshape of MALTESE CROSS

nematodes

parasites that are ELONGATED, bilaterally symmetrical, CYLINDRICAL, UNsegmented with SEPARATE sexes

Trichuris trichuria

APHASMID nematode; LEMON or BARREL shaped egg; also known as WHIP WORM

MOT: ingestion of EMBRYONATED egg

Capillaria philippinensis

APHASMID nematodes; PEANUT shaped egg; cause AUTOINFECTION

MOT: ingestion og LARVA in FISH

Capillaria hepatica

APHASMID nematode; LEMON shaped egg with PITTED shells in LIVER; DEAD-END infection in humans

MOT: ingestion of EMBRYONATED egg

Trichinella spiralis

APHASMID nematode; ENCYSTED LARVA in muscles; cause DEAD-END infection in humans

MOT: ingestion of encysted larva

Ascaris lumbricoides

PHASMID nematodes; GOLDEN BROWN mamiliated egg; MOST COMMON helminth worlwide can migreate from lung to heart

MOT: ingestion of EMBRYONATED egg

Enterobius vermicularis

PHASMID nematodes; D-shaped embryonated egg also known as PINWORM; collect specimen EARLY in morning; TAPE PREP is preferred for testing

MOT: ingestion of EMBRYONATED egg

Toxocara spp.

PHASMID nematode; LARVA in TISSUE causing VISCERAL and OCULAR LARVA MIGRANS diagnosed by serology

MOT: ingestion of MEBRYONATED egg

Hookworms

PHASMID nematode; COLORLESS egg with 2-8 cell stages inside THIN shell; cause GROUND ITCH and migration of lung to heart

MOT: SKIN PENETRATION by FILARIFORM larva

Strongyloides stercoralis

PHASMID nematode; RHABDITIFORM LARVA with PROMINENT genital primordium; also known as THREADWORM can migrate from heart to lung

MOT: SKIN PENETRATION by FILARIFORM larva

d. Paragonimus westermani

LARVA of all of the following nematodes can be seen in SPUTUM, EXCEPT:

a. Ascaris lumbricoides

b. Strongyloides stercoralis

c. Hookworms

d. Paragonimus westermani

Wuchereria bancrofti

filarial worm found in LYMPHATICS with NOCTURNAL periodicity; vector is ANOPHELES, CULEX, AEDES

Brugia malayi

filarial worms found in LYMPHATICS with SUBNOCTURNAL periodicity; vector is MANSONIA

Loa loa

filarial worms found in SUBCUTANEOUS TISSUE with DIURNAL periodicity; vector is CHRYSOPS

Onchocerca volvulus

filarial worm found in SUBCUTANEOUS TISSUE; use SKIN SNIPS as specimen; vector is SIMULIUM

Mansonella perstans

filarial worms found in MESETERIES that is NON periodic; vector is CULICOIDES

Mansonella streptocerca

filarial worms found in DERMIS or SUBCUTANEOUS TISSUE; use skin snips as specimen; vector is Culicoides

Mansonella ozzardi

filarial worms found in SUBCUTANEOUS that is NON periodic; vector is CULICOIDES

B. malayi, W. bancrofti, L. loa

filarial worms that are SHEATHED

[BWL]

W. bancrofti, O. volvulus, M. ozzardi

filarial worms that are NOT sheathed

d. Onchocerca volvulus

pathologic effects of filariae in humans are caused by ADULT WORMS in ALL BUT ONE species. in this case, principle damage is caused by microfilariae of?

a. Brugia malayi

b. Dracunculus medinensis

c. Wuchereria bancrofti

d. Onchocerca volvulus

Dracunculus medinensis

nematode recovered by observing INFECTED ULCERS for emergence of worms; INDUCED RUPTURE of infected ulcers by immersing in COOL WATER reveals FIRST-STAGE larvae

pseudophyllidea

type of cestodes; OPERCULATED eggs; life stages: (1) coraciium in water; (2) procercoid (FIRST intermediate host); (3) plerocercoid (SECOND intermediate host)

cyclophyllidea

type of cestode; NON operculated eggs with HEXACANTH EMBRYO (ONCOSPHERE); life stage: larva in intermediate host

cestodes

FLATTENED dorsoventrally, bilaterally symmetrical, SEGMENTED; HERMAPHRODITIC

Diphyllobothrium latum

cestode; "fish tapeworm" causing VIT B12 DEFICIENCY

adult: SPATULATE scolex without hook or rostellum

egg: OPERCULATE with SMALL KNOB at abopercular end

1ST IH: copepod; 2nd IH: fish

DH: man

Taenia solium

cestodse transmitted by ingestion of undercooked PORK; egg is infective to humans (CYSTICERCOSIS)

adult: QUADRATE scolex with ROSETLLUM and HOOK; uterus with 7-15 LATERAL branches

egg: HEXACANTH EMBRYO in RADIALLY STRIATED shell

IH: swine

DH: man

Taenia saginata

cestode transmitted by ingestion of undercooked BEEF; egg is infective to cattle NOT humans

adult: QUADRATE scolex without rostellum and hook; uterus wit h15-30 LATERAL branches

egg: HEXACANTH EMBRYO in a RADIALLY STRIATED shell

IH: cattle

DH: man

Hymenolepis nana

cestodes known as "dwarf tapeworm" may NOT require intermediate host

adult: KNOB-like scolex with ROSTELLUM and HOOKS

egg: HEXACANTH EMBRYO with FILAMENTS on polar thickening

IH: beetles, fleas

DH: rat, man

Hymenolepis diminuta

cestodes adult: KNOB-like scolex with ROSTELLUM but NO hooks

egg: HEXACANTH EMBRYO with NO filaments on polar thickenings

IH: rat fleas

DH: dog

incidental host: man

Dipyllidium caninum

cestodes with gravid proglottids ressembling RICE GRAIN or CUCUMBER SEEDS

adult: CONICAL scolex with HOOKS

egg: HEXACANTH EMBRYO in RADIALLY STRIATED SHELL

IH: dog lice

incidental IH: man

DH: canine

Echinococcus granulosus

cestodes also known as "hydatid cyst worm"; SHORTEST tapeworm

adult: GLOBULAR scolex with ROSTELLUM and HOOKS; uterus with 12-15 LATERAL branches

egg: HEXACANTH EMBRYO in RADIALLY STRIATED shell

IH: sheep

DH: dog or wild canine

incidental IH: man

c. snail

trematodes require what common intermediate host?

a. acquatic plants

b. crabs

c. snails

d. fish

a. cercaria

what is infective stage of Schistosomes?

a. cercaria

b. redia

c. metacercaria

d. sporocyst

b. direct penetration of skin by cercariae

mode of transmission of schistosomal infection by?

a. ingestion of contaminated aquatic vegetation

b. direct penetration of skin by cercariae

c. ingestion of raw fish

d. mosquito bite

2 redial stage

E. ilocanum has how many redial stages?

no redial stage

D. dendriticum has how many redial stages?

2 generations of sporocyst, no redia

Schistosoma spp. has how many redial stage and generation of sporocyst?

cercaria

infective stage of blood trematodes (Schistosome spp.)

metacercaria

infective stage of organ trematodes

b. Heterophyes heterophyes

what trematode is considered SMALLEST but DEADLIEST fluke?

a. Echinostoma ilocanum

b. Heterophyes heterophyes

c. Clonorchis sinensis

d. Schistosoma spp.

Fasciolopsis buski

LARGEST trematode

FIRST IH: snail

SECOND IH: aquatic plants

Echinostoma ilocanum

GARRISON'S fluke

FIRST IH: snail

SECOND IH: snail

Heterophyes heterophyes

DEADLIEST fluke causing MYOCARDITIS

FIRST IH: snail

SECOND IH: fish

Fasciola hepatica

SHEEP LIVER fluke

FIRST IH: snail

SECOND IH: aquatic plants