Microbiology Parasitology - First Aid Flashcards
Giardia lamblia disease
Giardiasis: bloating, flatulence, foul-smelling, fatty diarrhea (often seen in campers/hikers)
Transmission of Giardia lamblia
cysts in water
Diagnosis of Giardia
trophozoites or cysts in stool
Treatment for Giardia
Metronidazole
Entamoeba histolytica disease
Amebiasis: bloody diarrhea, liver abscess (w/ “anchovy paste” exudate), RUQ pain
Transmission of Entamoeba histolytica
Cysts in the water
Diagonsis of Entamoeba histolytica
serology and trophozoites (w/ RBCs in cytoplasm) or cysts (w/ up to 4 nuclei) in stool
Treatment of Entamoeba histolytica
Metronidazole
Iodoquinol for asymptomatic cyst passers
Cryptosporidium diesease
severe diarrhea in AIDS
mild disease in immunocompromised
Cryptosporidium transmission
oocysts in water
Diagnosis of Cryptosporidium
oocysts on acid-fast stain
Treatment of Cryptosporidium
prevention by filtering city water
Nitazoxanide in immunocompromised hosts
Protozoa that cause GI infections (3)
- Giardia lamblia
- Entamoeba histolytica
- Cryptosporidium
Protozoa that cause CNS infections (3)
- Toxoplasma gondii
- Naegleria fowleri
- Trpanosoma brucei
Toxoplasma gondii disease
brain abcesses in HIV (ring-enhancing lesions on CT/MRI) congenital toxoplasmosis (triad of chorioretinitis, hydrocephalus and intracranial calcifications)
Transmission of Toxoplasma gondii
cysts in meat or oocysts in cat feces; crosses placenta
Diagnosis of Toxoplasma gondii
serology, biopys (tachyzoite)
Treatment for Toxoplasma gondii
Sulfadiazine and pyrimethamine
Naegleria fowleri disease
Rapidly fatal meningoencephalitis
Trasmission of Naegleria fowleri
swimming in freshwater lakes; enters via cribiform plate
Diagnosis of Naegleria fowleri
amoebas in spinal fluid
Treatment of Naegleria fowleri
Amphotericin B
Trypanosoma brucei disease
African sleeping sickness: enlarged LNs, recurring fever, somnolence, coma
Transmission of Trypanosoma brucei
tsetse fly (painful bite)
Diagnosis of Trypanosoma brucei
blood smear
Treatment for Trypanosoma brucei
Suramin for blood-borne disease
Melarsoprol for CNS penetration
Protozoa that cause hematologic infections
- Plasmodium
2. Babesia
Plasmodium Disease
fever, HA, anemia, splenomegaly
P. vivax/ovale
48 hour cycle (fevers on first and third days) dormant form (hypnozoite) in liver
P. falciparum
severe
irregular fever patterns
parasitized RBCs occlude capillaries in brain (cerebral malaria), kidneys and lungs
P. malariae
72 hr cycle (quartan)
Transmission of Plasmodium
mosquito
Diagnosis of Plasmodium
- blood smear, trophozoite ring form within RBC
- schizont containing merozoites
Treatment of Plasmodium
Begin with chloroquine which blocks Plasmodium heme polymerase; if resistant, use mefloquine or atovaquone/proguanil.
If Plasmodium infxn is life-threatening, treat with…
IV quinidine (check for G6PD deficiency).
For vivax/ovale treatment, add…
primaquine for hypnozoites 9test for G6PD deficiency).
Babesia disease
Babesisosis: fever and hemolytic anemia; northeast US; asplenia increases risk of disease
Transmission of Babesia
ixodes tick
Diagnosis of Babesia
blood smear has ring form and Maltese cross
PCR
Treatment of Babesia
Atovaquone + Azithromycin
Trypanosoma cruzi disease
Chagas disease: dilated cardiomyopathy, megacolon, megaesophagus
(South America)
Transmission of Trypanosoma cruzi
Reduviid bug (“kissing bug”) feces, deposited in a painless bite
Diagnosis of Trypanosoma cruzi
blood smear
Treatment for Trypanosoma cruzi
Benznidazole
Nifurtimox
Leishmania donovani disease
visceral leishmaniasis: spiking fevers, hepatosplenomegaly, pancytopenia
Transmission of Leishmania donovani
sandfly
Diagnosis of Leishmania donovani
macrophages containing amastigotes
Treatment of Leishmania donovani
Amphotericin B, sodium stibogluconate
Trichomonas vaginalis Disease
Vaginitis: foul-smelling, greenish discharge; itching and burning
Transmission of Trichomonas vaginalis
sexual (cannot exist outside of humans because it cannot form spores)
Diagnosis of Trichomonas vaginalis
trophozoites on wet mount
strawberry cervix
Treatment of Trichomonas vaginalis
Metronidazole for pt and partner
Intestinal Nematodes (roundworms)
Enterobius vermicularis (pinworm)
Ascaris lumbricoides (giant roundworm)
Strongyloides stercoralis
Ancylostoma duodenale/Necator americanus (hookworms)
Transmission of Enterobius vermicularis
fecal-oral
Enterobius vermicularis disease
Intestinal infection causing anal pruritis (diagnosed via scotch tape test)
Treatment for Enterobius vermicularis
Bendazoles or ppyrantel pamoate
Transmission of Ascaris lumbricoides
fecal-oral; eggs visible in feces under microscope
Disease of Ascaris lumbricoides
intestinal infection
Treatment for Ascaris lumbricoides
Bendazoles or pyrantel pamoate
Strongyloides sterocralis transmission
larvae in soil penetrate the skin
Strongyloides stercoralis disease
intestinal infection causing vomiting, diarrhea, epigastric pain
Treatment for Strongyloides
Ivermectin or albendazole
Transmission of Anyclostoma duodenale or Necator americanus
larvae penetrate skin
Anyclostoma/Necator disease
intestinal infection causing anemia by sucking blood from intestinal walls
Treatment of Ancylostoma/Necator
Bendazoles or pyrantel pamoate
Tissue Nematodes
Onchocerca volvulus
Loa loa
Wuchereria bancrofti
Toxocara canis
Transmission of Onchocerca volvulus
female blackfly bite
Onchocerca volvulus disease
hyperpigmented skinand river blindness; allergic rxn to microfilaria possible
Onchocerca volvulus treatment
Ivermectin
Loa loa transmission
deer fly, mango fly, horse fly
Loa loa disease
swelling in skin, worm in conjunctiva
Loa loa treatment
Diethylcarbamazine
Wuchereria bancrofti transmission
female mosquito
Wuchereria bancrofti disease
blocks lymphatic vessels: elephantiasis: takes 9 months - 1 yr after bite to become symptomatic
Treatment for Wuchereria bancrofti
Diethylcarbamazine
Toxocara canis transmission
fecal-oral
Toxocara canis disease
visceral larva migrans
Toxocara canis treatment
Albendazole or mebendazole
Cestodes (tapeworms)
- Taenia solium
- Diphyllobothrium latum
- Echinococcus granulosus
Taenia solium transmission
ingestion of larvae encysted in undercooked pork or ingestion of eggs
Taenia solium disease
- intestinal infection (from larvae)
- cysticercosis (from eggs)
- neurocysticercosis (from eggs)
Treatment for Taenia solium
Praziquantel
Also, albendazole for neurocysticercosis.
Diphyllobothrium latum transmission
ingestion of larvae from raw freshwater fish
Diphyllobothrium latum disease
vitamin B12 deficiency (tapeworm competes for B12 in intestine) leading to anemia
Treatment for Diphyllobothrium
Praziquantel
Echinococcus granulosus transmission
ingestion of eggs from dog feces
Echinococcus granulosus disease
Hydatid cysts in liver, causing anaphylaxis if antigens are release (surgeons preinject with ethanol to kill cysts)
Treatment for echinococcus
Albendazole
Trematodes (flukes)
- Schistosoma
2. Clonorchis sinensis
Schistosoma transmission
snails are host; cercariae penetrate skin of humans
Disease from Schistosoma
Liver and spleen granulomas, fibrosis and inflammation
Chronic infection with schistosoma can lead to…
SCC of the bladder.
Treatment for schistosoma
Praziquantel
Clonorchis transmission
undercooked fish
Clonorchis sinensis disease
biliary tract inflammation leading to pigmented gallstones.
Clonorchis sinensis is associated with…
cholangiocarcinoma.
Treatment for Clonorchis
Praziquantel