Parasitology Reviewer

Monica Kristine Reyes

ASCARIS

Unfertilized vs. fertilized egg (eggs are the non-infective stages)

Infective stage: embryonated

Unfertilized eggFertilized eggs

Adult Trichuris• Male has COILED posterior end • Habitat: found in colon; mainly in cecum

Trichuris egg

• Prominent BIPOLAR plugs

Capillaria egg

• With FLAT bipolar plugs (similar to Trichuris na bipolar pero mas flat)

• STRIATED capsule

BUCCAL CAPSULE: hookworms

Acylostoma duodenaleNecator Americanus

Hookworm eggEnterobius egg

Microfilaria

Ancylostoma duodenale

• 2 pairs of teeth

Mukhang tiger! RAAAAAAR! =)

Necator Americanus

Looks like penis to me. Haha!

Hookworm egg• Thin egg shell• Germ cells happen to be in clusters• Morula stage: egg cells start to divide

Parang plastic balloon yung casing di ba? =)

Enterobius eggs• Deposited at perianal space• Coating: for attachment (primary manifestation is

PRURITUS…kaya nagkakamot ng pwet ang pasyente; usually paggabi)

• Egg shell is FLAT on ONE side (Trichuris: bipolar, nakabulge…Capillaria: bipolar din pero medyo flat…ang Enterobius, parang napipi ang isang side)

• Larva in external structures• Very easy transmission due to larva in egg (matures in

4-6 hours)• Can be acquired through inhalation

Enterobius eggs

Fertilized enterobius egg

Enterobius eggs in colon

Microfilaria

• Criculates in blood• Periodicity; NIGHT time (collect blood sample

8pm-2am)• ICT: immunochromatography test (can detect

it even during daytime):card test; antigen detection test

Microfilaria

(Wuchureria bancrofti) microfilariaCephalic phase: generally short

Cephalic space: generally shortSomatic cells: discrete and body nuclei separate

Microfilaria

• Brugia Malayi

Big somatic cells: overlappingLonger cephalic space

SCOLICES: tapeworms

Taenia soliumTaenia saginata

Schistosoma japonicumParagonimus Westermani

Taenia solium

• Armed scolex• Rostellum with hooklets• PORK

Gravid segments: main uterus with lateral branches8 to 12 lateral segments

Taenia saginata

• Unarmed scolex• BEEF

Lateral branches: 15 or more

Solium is worse than saginata…may cyst deposition kasi sa CNS ang solium

Taenia eggs

• Cannot differentiate from each other (solium and saginata)

Adult Schistosoma Japonicum

• Canal (GYNECOPHORAL): used by male to carry female during copula (how sweet!)

• Parang Filipino men: sweet pero polygamous!

Schistosoma eggs

• No operculum but with miracidium• Not mature when passed out by female• Matures in tissues

eggs are usually round and have a small spine or no spine. (lateral knob)

Oncomelania Hupensis Quadrasi

• Intermediate host of local S. japonicum

Immature Paragonimus Westermani

• Very WIDE OPERCULUM• Germ cells: immature; no miracidia• Abopercular thickening

Adult Paragonimus eggs

• Localized in lungs; “lung fluke”• Mistaken for TB• Main manifestation- hemoptysis

Sundathelphusa Philippina

• Intermediate host: Paragonimiasis• 1st pair of arm: one is smaller (R<L)

Echinostoma: intestinal flukes

• Kuhol: can carry metacercaria of Echinostoma (intestinal fluke)

Entamoeba Histolytica cyst

• Chromatoidal bar: rounded ends (cigar-shaped)

:product of excess food

Entamoeba Trophozoite

• Long and fingerlike pseudopodium• Invasive psuedopodium: can carry RBC• Certally located nucleus and nucleolus

Entamoeba coli cyst

• 1-8 nucleated cyst• Off-centered, eccentric nucleus• Chromatoidall bar; jagged ends; “needle

sticks”

Giardia lamblia

• Smiling face; binucleated

Trypanosomes

• What OFWs bring home: Leishmania and Trypanosomes

malaria

P. falciparum

• Malignant malaria• Ring stages: 1/5 of infected cell• Inbetween rings and germ cells/ gametocytes• Mature every 36-40 hours • Schizonts: smooth muscle organ vasculature• Peripheral smear: if these appear, emergency

case na!

P. vivax

• Tendency: young RBCs• Pigments: Sheffner’s dots (degradative

products)• Mature Schizonts: 12-24 merozoites • Merozoites: released when matured; invade

other RBCs • Mature every 48 hours (asexual phase)

P. malariae

• BAND formation• “belt” trophozoite• Normal sized RBCs• Mature every 72 hours (asexual phase)• Produces FEWEST merozoites• Flower: rosette formation (Schizonts)