Parasitology Flashcards
Pseudopod-forming nonflagellated protozoa –> Brownian movement
Entamoeba histolytica
Most invasive parasite among entamoeba
E. Hystolytica
IS of E. Hystolytica
Mature cysts
DS of E. Hystolytica in diarrheal stools
Trophozoite
DS of E. Hystolytica in non diarrheal stools
Cyst
Pathogenesis/ virulence of E. Hystolytica
3
Lectin
Amebapores
Cysteine proteases
Mediates adherence in E. Hysolytica
Lectin
For penetration in E Hystolytica
Amebapores
For cytopathic effect in E hystolytica
Cysteine proteases
Dysentery without fever
Flask shaped colon ulcer
Amebic colitis
E hystolytica
Granulomatous lesion in the cecal or rectosigmoid
Ameboma
E hystolytica
Most common extraintestinal form where you can aspirate an anchovy paste like aspirate
Amebic liver abscess in e hystolytica
DOC for asymptomatic carrier of e hystolytica
Diloxanide furoate
Tx for amebic colitis
Metronidazole
Tinidazole
Tx for amebic liver abscess
Metronidazole
Tinidazole
Flagellate that leaves in duodenum, jejunum and upper ileum
Giardia lamblia
Falling leaf motility
G lamblia
IS of giardia lamblia
Cysts
Trophozoite is pear shaped with 2 nuclei, 4 pairs of flagella and a suction disk with which it attaches to intestinal wall
Giardia lamblia
Ultimately leads to enterocyte apoptosis
G lamblia
In acute infection there is an watery foul smelling diarrhea
Excessive flatus, smelling like rotten eggs
No fever and non bloody
G lamblia
There is steatorrhea in chronic infection
G lamblia
String test
G lamblia
Opportunistic infection in intestinal protozoa that undergoes schizogony and gametogeny
Cryptosporidium hominis / parvum
Mode of transmission of E. Hystolytica, G. Lamblia and C. Hominis/ Parvum
Fecal-oral
IS of c parvum/hominis
Thicked wall oocysts
Uses modified Kinyouon acid fasts tain for thick walled oocyst
C hominis/ parvum
What site in c parvum infection is most heavily infested?
Jejunum
Self limited non bloody diarrhea in immunocompromised patients
C parvum/ hominis
DOC for immunocompetent patients with c hominis
Nitazoxanide
Tx for immunocompromised pts with c hominis infx
None
But paromycin may be helpful in reducing the diarrhea
Tx for HIV patients with c hominis infx
HAART
Highly activated antiretroviral therapy
Only ciliated protozoan that causes humann disease (diarrhea)
Balantidium coli
Largest protozoan parasite of humas
Balantidium coli
IS of balantidium coli
Cysts
Extraintestinal lesion DOES NOT occur
Balantidium coli
Tx of choice for balantidium coli
Tetracycline
Urogenital protozoa that exists only as trophozoite
Trichomonas vaginalis
Pear shaped flagellated tropozoite with jerky motion
Cannot exist outside human cuz it cannot form cysts
Trichomonas vaginalis
Mode of transmission for T. Vaginalis
Sexual intercourse
Pingpong transmission
IS for t. Vaginalis
Trophozoite
What disease that has watery, foul smelling, greenish discharge accompanied by itching and burning
Trichomoniasis
Morphologically similar to e. Hystolytica but their DNA ribosomal RNA are different
Entomoeba dispar
Similar to e. Hystolytica but is much smaller and does not ingest RBC
E. Hartmanni
Parasite of pigs and monkey
Cysts is uninucleated
Entomoeba polecki
Most important parasitic disease in man
Plamodium species
What is the mosquito in plasmodium
Anopheles minimus flavirostris
IS of plasmodium
Sporozoites
DS of plasmodium
Trophozoite (ring forms)
Diagnostic test for malaria
Thick and thin smears with giemsa stain
Thick smear is to
Screen for presence of organism
Identification of species
What smear to use?
Thin smear
When to take blood samples where in there is highest yield in malaria
During fever
2-3 hours after peak
People with RBC defects (G6PD def, sickle cell) are protected against
P. Falciparum / malaria
Black water fever
Malaria
Acute renal failure
What do you call the Recurrence of symptoms after temporary abatement (2-4 weeks)
Recrudescence
Recrudescence is seen in
P. Falciparum and P. Malariae
What do you call the Return of disease after its apparent cessation (1-6 mos) due to reactivation of hypnozoites?
Relapse
Relapse is seen in
P. Ovale/ P. Vivax
Infected RBC with 1-2 small chromatin dots
P. Falciparum
Infected RBC with presence of ring form stage only
P. Falciparum
Infected RBC with presence of band form stages
P. Malariae
Asexual cycle of P malariae
72 hours
Asexual cycle of p falciparum, p vivax, p ovale
48 hours
Benign tertian periodicity
P vivax, p ovale
Benign quartan
P malriae
Malignant tertian
P falciparum
Rbc preference: all ages
P falciparum
Rbc preference: old rbc
P malariae
Rbc preference: young rbc
P vivax
P ovale
Highest parasitemia in blood and tissue protozoa
P falciparum
Lowest parasitemia in blood and tissue protozoa
P malariae
Gametocyte: banana-shaped
P falciparum
Gametocyte: Small round
P ovale
Gametocyte: compact
P malariae
Gametocyte: large round
P vivax
Malarial dots: schuffner
P vivax, p ovale
Malarial dots: maurer
P falciparum
Malarial dots: ziemann
P malariae
Malarial dots: punctate granulations
Schuffner
Malarial dots: coarse granulation
Maurer
Malarial dots: Fine dots ziemann
P malariae
Tx for P ovale and P vivax infection
Chloroquine + Primaquine
tx for Uncomplicated infections with chloroquine resistant falciparum
Quinine + doxycycline/ clindamycin
Chloroquine resistance
Mefloquine + Doxycycline
Eradication of hypnozoites
Primaquine
Severe cases or pregnant
Quinidine or quinine
Domestic cat is the definitive host
Toxoplasma gondii
Transmission of Toxoplasma gondii #2
Ingestion of cysts in raw meat or contaminated food
Transplacentally
IS in Toxoplasma gondii
Fecal oocytst
DS for Toxoplasma gondii
Trophozoite (bradyzoites)
What microscopic examination is used in Toxoplasma gondii which shows a cresent shaped trophozoites
Toxoplasma gondii
Some resemble infectious mononucleosis
What disease?
Toxoplasmosis
Found on MRI of immunocompromised patient with toxoplasmosis
Multiple ring-enhancing lesions
Tx of choice for Toxoplasma gondii
Sulfadiazine + pyrimethamine
Tx for toxoplasmosis in pts who cannot receive sulfa drugs
Clindamycin added to pyrimethamine
Leishmaniasis is due to a bite of
Female sandfly
Of the genus phlebotomus or lutzomyia
IS for lesihmania
Promastigote
DS for leishmania
Amastigote
3 types of leishmaniasis
Cutaneous
Mucocutaneous
Visceral
Causative agent for cutaneous leishmaniasis
L. Brazillensis
Causative agent for visceral leishmaniasis
L. Donovani
Local name for cutaneous leishmaniasis
Oriental sore
Local name for mucocutaneous leishmaniasis
Espundia
Local name for visceral leishmaniasis
Kala-azar
Conventional therapy for leishmaniasis
Sodium stibogluconate
Pentavalate antimonial
2nd line agent for leishmaniasis #2
Amphotericin B
Pentamidine
Protozoa due to a bite of ixodes tick
Babesia microti
Same with borreliia burgdorferi of lyme dse
Maltese cross in giemsa stained blood smears
Babesia microti
Disease caused by a protozoan where in asplenic patients are affected more severely
Babesiosis
DS for cyclospora cayatenensis
Spherical oocysts in a modified acid fast stain of a stool sample
Tx for cyclospora cayetanensis
Trimethoprim-sulfamethoxazole
IS of isospora belli
Oocyst
Tx for isospora belli
Trimethoprim-sulfamethoxazole
This protozoa ha 4 forms: amastigote, promastigote, epimastigote, trypomastigote
Trypanosoma cruzii
Transmission of Trypanosoma cruzii
Reduviid bag
Kissing bug
Triatoma or cone nose
Painless bite
IS of Trypanosoma cruzii
Metacyclic trypomastigote
DS of Trypanosoma cruzii
Trypomastigote
Xenodiagnosis as one of the lab dx for
Trypanosoma cruzii
What is the most severely and frequently affected tissue in trypanosomiasis
Cardiac muscle
Chaga’s disease or american trypanosomiasis
Trypanosoma cruzii
Chagoma
Trypanosoma cruzii
Unilateral palpebral swelling or Romana’s sign
Trypanosoma cruzii
Drug of choice for Trypanosoma cruzii
Nifurtimox
Alternative: Benznidazole
It has only 2 forms: epimastigote, trypomastigote
Trypanosoma brucei
Transmission of Trypanosoma brucei
Tsetsefly
Painful bite
IS for Trypanosoma brucei
Metacyclic trypomastigote
Trypanosoma brucei gambiense is transmitted by
Glossina papalis or riverine tsetse
Causes dse along water courses in west africa
Tryposoma brucei gambiense
Found in the arid regios of east africa
Trypanosoma brucei rhodesiense
Transmitted by glossina morsitans or savannah tsetse
Trypanosoma brucei rhodesiense
There is a cyclical fever spike
Trypanosoma brucei
Winterbottom’s sign
Kerandel’s sign
In what disease?
African trypanosomiasis or african sleeping sickness
Winterbottom’s sign - enlargement of posterior cervical lymph nodes
Kerandel’s sign - deep hyperesthesia
Most common protist in soil
Acanthamoeba castellani
Carried in eyes during trauma
Acanthamoeba castellani
IS of Acanthamoeba castellani
Trophozoites
Most common disease associated with acanthamoeba infection
Keratitis
Tx for Acanthamoeba castellani
Pentamidine
Ketoconazole
Flucytosine
Most common parasite that contaminates contact lenses
Acanthamoeba castellani
Transmitted by swimming in freshwater lakes
Naegleria fowleri
IS of Naegleria fowleri
Trophozoites
Trophozoites can penetrate nasal mucosa and cribriform plate
Naegleria fowleri
Tx for Naegleria fowleri
Amphoterin B
Toxin involved in paralytic syndrome of shellfish poisoning
Saxitoxin
15 mins
Neurotoxic syndrome in shellfish poisoning
Brevetoxin
15 mins
Diarrhetic syndrome in shellfish poisoning
Okadaic acid
30 mins
Amnesic syndrome in shellfish poisoning
Domoic acid
30 mins
Tx for shellfish poisoning
Gastric lavage with activated charcoal
Improve muscle weakness in shellfish poisoning
Neostigmine and endrophonium
Site affected in echinococcus granulosus
Liver
Tx for echinococcus granulosus
Albendazole
Transmission: schistosoma japonicum
Penetrate skin
Transmission: pargonimus westermani
Ingested raw crab
Transmission: clonorchis sinensis
Ingested raw fish
Ascariasis
Specie?
Ascaris lumbricoides
Hookworm
Species?
Ancylosotoma duodenale
Necator americanus
Whipworm
Specie?
Trichuris trichiura
Pinworm
Specie?
Enterobius vermicularis
Filariasis
Species?
Wuchereria bancrofti
Brugia malayi
Trichonosis
Specie?
Trichinella spiralis
Transmission is thru larval penetration of skin
Strongyloides stercoralis
Ancylosotoma duodenale
Tx for trichuris trichiura/ whipworm
Mebendazole
Tx for pinworm
Enterobius vermicularis
Pyrantel pamoate
Tx for trichinella spiralis
Thiabendazole
Cestode that has 4 suckers and circle of hooks arranged arpund a rostellum
Taenia solium
Gravid proglottids of Taenia solium has how many branches?
5-10