✅Parasitology Flashcards
Simple life cycle is defined as
Having one host only
Free living organism that passes through the digestive tract without infecting the host
Spurious parasite
Types of hosts. Define each.
Definitive or final host - parasite attains sexual maturity
Intermediate hosts - harbors asexual or larval stages
Paratenic hosts - parasite does not develop further to later stages
Reservoir hosts - allow life cycle to continue and become addl sources of human infections
Types of vectors. Describe each.
Biologic - transmits parasite only after it has completed its development
Mechanical or phoretic vector - transmits only the parasite
E. Histolytica trophozoites secrete ____ which digest cellular material
Cysteine proteases
T. gambiense mechanism if immune evasion
Antigenic variation (surface protein variation)
Example of a facultative parasite
Strongyloides stercoralis
T gambiense evades the immune system by
Antigenic variation
E granulosus evades the immune system by
Carrying blood group antigens
Toxoplasma evades the immune sysem by
Multiplying inside macrophages
E histolytics produces suppressor factor that
Inhibits monocyte movement.
Kingdim protozoa is divided into
Sarcodina
Sporozoa
Mastigophora
Ciliata
Helminths (metazoa) are divided into
Nemathelminthes (roundworms)
Platyhelminthes (flatworms)
- – trematoda (flukes)
- – cestoda (tapeworms)
Movement of entamoeba
Pseudopods
Brownian movement
Infective stage of entamoeba histolytica
Mature cysts
Virulence factors of entamoeba
Lectin - mediates adherence
Amebapores - penetration
Cyseteine proteases
Spectrum of disease of entamoeba
Cyst carrier
Amebic colitis - dysentery without fever
Ameboma - assoc with dysentery
Amebic liver abscess
Most common extraintestinal form of entamoeba
Amebic liver abscess
Morphology of ulcers in amebic colitis
Flask shaped
Treatment of amoeba in cyst carrier state, amebic colitis and amebic liver abscess
Cyst carrier state - diloxanide furoate
Amebic colitis and amebic liver abscess - metronidazole
Add percutaneous drainage for non responders in amebic liver abscess
3 protozoans that can be treated wity metronidazole
Entamoeba
Giardia
Trichomonas
Luminal agents in amoebiasis include
Diloxanide furoate
Iodoquinol
Paromomycin
Protozoan
Old’s man’s face
Falling leaf motility
Giardia lamblia
Infective stage of giardia
Cyst
Diagnostic stage of giardia
Cysts and trophozoites
Most common cause of backpacker’s diarrhea
Giardia lamblia
Main pathophysiology of giardia infection
Malabsorption
Symptoms of giardiasis -acute
Ab pain
Diarrhea
EXCESSIVE FLATUS SMELLING LIKE ROTTEN EGGS
Parasitic cause of Diarrhea In HIV
Cryptosporidium parvum
Infective and diagnostic stage of cryptosporidium parvum
Thick walled oocysts
Urogenital protozoan
Trichomonas vaginalis
Protozoan with no cyst stage
Trichomonas vaginalis
Characteristic transmission of trichomonas
Ping pong transmission
Sexual intercourse
Characteristic cervic in trichomonas
Strawberry cervix
Disease presentation of trichomoniasis
Watery foul smelling greenish vaginal discharge accompanied by itching and burning
Strawberry gallbladder
Cholesterolosis
Berry aneurysms
Investigate for
SAH
ADPKD
COARCTATION
Mulberry molars
Congenital syphilis
Mulberry tumor
Tuberous sclerosis
Blueberry muffin baby
Congenital rubella
CMV
Disseminated neuroblastoma
Grape like vesicles
Hydatidiform mole
Grape like odor
P. aeruginosa
Banana shaped gametocytes
Plasmodium falciparum
Banana shaped left ventricle
Hypertrophic cardiomyopathy
Orange cast skin
Leptospirosis
Orange colonies
N. asteroides
Pear shaped trophozoites
Giardia
Trichomonas
Pear shaped organ
Prostate
How is trichomonas vaginalis treated?
Single dose oral metronidazole 2grams (4 -500mg tab)
Most impt parasitic disease in man
Malaria
Definitive host of plasmodium
Mosquito
Malaria is transmitted by -_____
Anopheles flavirostris minimus
Infective stage of malaria
Sporozoites
Dormant form of plasmodium vivax and ovale in the liver are called
Hypnozoites
To treat hypnozoites, treat with
Primaquine
Malarial schizonts released from the blood
Merozoites
Partial immunity called ____ is seen in individuals who completely recover from falciparum malaria
Preminition
Asexual cycle of all plasmodia is 48 hrs except
P malariae
72 hrs
Also benign quartan periodicity
Plasmodium that has the affinity for young RBCs
Vivax and ovale
Merozoites are highest in plasmodium ___
Vivax
Identify malarial species mentioned :
Banana shaped gametocytes
P. Falciparum
Identify malarial species mentioned :
Large round gametocytes
Vivax
Identify malarial species mentioned :
Small round gametocyte
Ovale
Identify malarial species mentioned :
Cerebral malaria
Falciparum
Increased severity of a disease after remission
Recrudescence
Identify malarial species mentioned :
Recrudescence
Falciparum
Malariae
Identify malarial species mentioned :
Relapse
Vivax
Ovale
Malarial relapse is due to
Reactivation of hypnozoites
Malarial diagnosis using
Thin and thick smears
Thick - screen for presence
Thin - species identification
Malarial diagnosis has the highest yield when blood samples are taken during
Fever or
2-3 hours after peak
Malarial dots in P. Falciparum
Describe.
MAURER DOTS - Coarse granulations seen in RBCs
Malarial dots in P malariae
Describe.
ZIEMANN DOTS
FINE DOTS present in RBCs
Malarial dots in P. Vivax and ovale
Describe.
SCHUFFNER DOTS
punctate granulations present in RBCs
Granulomas in cerebral malaria
Durck granulomas
Acute renal failure in malaria
Blackwater fever
Septic shock in malaria
Algid malaria
Areas of high malarial endemicity
Palawan
Kalinga apayao
Ifugao
Agusan del sur
Areas of high malarial chloroquine resistance
Palawan, davao del norte, compostela valley
PDC
Classic textbook treatment for malaria
Falciparum - chloroquine
Vivax and ovale - chloroquine + primaquine
Give the malarial drug
Tissue schizonticide
Primaquine
Give the malarial drug
Blood schizonticide
Chloroquine
Quinine
Give the malarial drug
Gametocide
Primaquine
Give the malarial drug
Sporonticide
Proguanil
Pyrimethamine
Name the treatment for malaria in the following:
Chloroquine resistance
Mefloquine +doxy
Name the treatment for malaria in the following:
Eradication of hypnozoites
Primaquine
Name the treatment for malaria in the following:
Severe cases or pregnant patients
Quinidine
Quinine
Insect repellants with _____ can be used in malaria.
DEET
Ex of biological modification of malaria
Cultivation of snails that eat up mosquito larvae
Definitive host if toxoplasma
Cat
Transmission of toxoplasma
Ingestion of cysts in raw meat and contaminated food
Transplacentally
Infective stage of toxoplasma gondii
Fecal oocysts
2 types of toxoplasma trophozoites
Tachyzoites
Bradyzoites
Preferred diagnostic test for toxoplasmosis
IgM antibody
Heterophile negative mononucleosis
CMV and Toxoplasma
Findings of enceph in toxoplasmosis
Ring enhancing lesions
Intracranial findings in congenital toxoplasmosis
Intracranial calcifications
Treatment of toxoplasmosis
Sulfadiazine plus pyrimethamine
Trypanosoma cruzi is transmitted by the
Reduviid bug / triatoma bug
Infective stage of T. Cruzi
Metacyclic trypomastigotes
Treatment for chagas disease
Nifurtimox
Most frequently and severely affected tissie in chagas disease
Cardiac muscle
Allowing an uninfected, laboratory raised reduviid bug to feed on the patient for dX
Xenodiagnosis
Periorbital edema in acute chagas disease
Romaña’s sign
Nodule near the bite if the reduviid bug in chagas disease
Chagoma
Chronic chagas disease manifests with
Myocarditis
Megacolon
Megaesophagus (achalasia)
Forms of T cruzi
4
Amastigot
Promastigote
Epimastigote
Trypomastigote
Forms of trypanosom brucei
2
Epimastigote
Trypomastigote
T brucei is a complex made up of 2 members namely:
T brucei gambiense
T brucei rhidesiense
Vector of t brucei
Tsetse fly
Other name for tse tse fly
Glossina
Infective stage of t brucei
Metacyclic trypomastigotes (same as chagas)
Cyclical fever spike of african sleeping sickness happens every?
2 weeks
Which is a more fatal sleeping sickness?
Rhodesian is more fatal than gambian
Sleeping sickness geographical distribution
Think WGER!
Western gambian
East rhodesian
Western gate
Eastern road
Enlargement of the posterior cervical LN in african sleeping sickness
Winterbottom’s sign
Hyperesthesia in african sleeping sickness
Kerandel’s sign
Encephalitis in african sleeping sickness manifests as plasma cells with cytoplasmic Ig globules. These cells are called
Mott cells
Treatment for african sleeping sickness Accdg to disease and geography
Blood borne disease - Suramin
CNS penetration - Melarsoprol
West african
- early: pentamidine
Cns involvement: eflornithine
east african
-early suramin
Cns involvement: melarsoprol
Most common cause of red tide in the PH is
Pyrodinium bahamense var compressum
Transmission of red tide is through
Bivalve molluscs
Shellfish poisoning syndromes: name the toxin.
Paralytic
Saxitoxin
Shellfish poisoning syndromes: name the toxin.
Neurotoxic
Brevetoxin
Shellfish poisoning syndromes: name the toxin.
Diarrhetic
Okadaic acid
Shellfish poisoning syndromes: name the toxin.
Amnesic
Domoic acid
Treatment for red tide poisoning
Gastric lavage with activated charcoal
Fluids
Intubation if with resp failure
Neostigmine and edrophonium to improve muscle weakness
Free living amoeba
Primary amebic menigoencephalitis acquired while swimming in contaminated pools
Naegleria fowleri
Only ciliated protozoan to cause human disease
Balantidium coli
Morphology of ulcers in balantidium coli infection
Round based wide neck intestinal ulcers
Babesiosis is transmitted by the bite of
Ixodes tick
Ring shaped trophozoites in tetrads
Maltese cross pattern
Babesia microti
Leishmanaiasis is transmitted by
Sandlfly phlebotomus
Spectrum of leishmanaisis:
Cutaneous
Leishmania tropica
Spectrum of leishmanaisis:
Visceral/kala azar
Leishmania donovani
Spectrum of leishmanaisis:
Mucocutaneous
Leishmania brasiliensis
Doc in leishmaniasis
Sodium stibogluconate
Antimony based compounds
Coccidial sporozoa that cause diarrhea in the immunocompromised
Cyclospora cayatenensis
Isospora belli
Treatment for diphyllobothrium latum
Praziquantel
Treatment for echinococcus granulosus
Albendazole
Treatment for taenia
Praziquantel
Taenia that manifests more with intestinal obstruction and pruritus ani
Taenia saginata
Taenia that manifests with mild intestinal symptoms and seizures
Taenia solium
Infective stage of d latum
Plerocercoid larvae
What nutrient deficiency is seen in d latum
Infection?
Vitamin B12 deficiency
Definitive host of echinoccoccus granulosus
Dog