Parasitology Flashcards
Patient presents with foul smelling diarrhea. History reveals he was out camping and he and his buddies decided to try and sanitize their own water from a nearby stream. He shows you pictures from the trip that include beavers building a dam. What would do to confirm diagnosis of the suspected culprit and how is it treated?
Giardia lamblia
-trophozoites or cysts in stool
Tx: Metronidazole (MOA thought to produce excessive free radicals in parasites leading to death)
A patient presents with bloody diarrhea and RUQ pain. Treatment with standard beta lactam antibiotics is ineffective and a biopsy of the liver shows a flask shaped ulcer formation. Serology shows trophozoites in the stool. What is the treatment?
Entamoeba histolytica
Tx: Metronidazole and Iodoquinol
A patient presents with severe watery diarrhea. His CD4 count is less than 200 now and he is diagnosed with AIDS. What is the best way to diagnose and best treatment for the most common causative agent?
Cryptosporidium
Dx: Acid fast oocysts
Tx: Nitazoxanide
Patient presents with chorioretiniits, hydrocephalus, and X ray shows intracranial calcifications. What is the best treatment?
Toxoplasma gondii
Tx: Sulfadiazine + Pyrimethamine
Patient presents with irritability and altered mental status. He reports that “things don’t smell right”. He expires a few hours after admission. What would be revealed in the CSF?
Naegleria fowleri
-amoebas in CSF, no effective Tx
An immigrant from Africa presents with intense somnolence and enlarged lymph nodes. He slips into an unarousable coma an hour after admission. What is the mode of transmission of the most likely causative agent and its treatment?
Trypanosoma brucei (African Sleeping Sickness)
-Tsetse fly bite
Tx: Suramin or Melarsoprol
Patient presents with fever, headache, anemia, and splenomegaly. History reveals that he returned from a trip to Africa 7 months ago and had similar symptoms then but cannot remember what they gave to treat him, but it was effective. What is the best course of action for this case?
Plasmodium vivax
-malaria that is sequestered in the liver
Tx: chloroquine (for circulating malaria) + primaquine (for the dormant hypnozoite form in liver)
Patient presents with intense fever. Blood smear indicates a hemolytic anemia with a maltese cross shape visible in RBCs. What is the mode of transmission and the treatment?
Bebesia microti
-Ixodes tick bite
Tx: quinine, clindamycin
Patient presents with difficulty swallowing and constipation. Barium swallow reveals “bird beak sign”. What is the mode of transmission and treatment?
Trypanosomi cruzi (Chagas disease)
-Reduviid Bug
Tx: Nifurtimox
Patient presents with spiking fevers and hepatosplenomegaly. CBC reveals pancytopenia and blood smear reveals amastigotes in macrophages. What is the mode of transmission and treatment?
Leishmania donovani
-Sandfly
Tx: Sodium Stibogluconate
Patient presents with anal pruritis. What test would confirm diagnosis and what is the treatment?
Enterobius vermicularis (pinworm)
-scotch tape prep
Tx: mebendazole or pyrantel pamoate
Patient presents with a funny feeling around the anus. visual exam notes sizable worms exiting the anal canal. What is the treamtne t for this condition?
Ascaris lumbricoides (giant roundworm) Tx: mebendazole or pyrantel pamoate
Patient presents with terrible muscle aches and periorbital edema. What is the treatment?
Trichinella sprialis
-cysts end up in muscle fibers
Tx: mebendazole
Patient presents with vomiting and diarrhea. CBC reveals normochromic anemia. What is the treatment?
Strongyloides Stercoralis
Tx: mebendazole or ivermectin
Patient presents with abdominal pain and anemia. History reveals he runs barefoot on the beach every morning. What is the treatment?
Ancylostoma duodenale or Necator americanus (hookworms)
Tx: mebendazole or pyrantel pamoate
Patient presents with terrible skin ulceration and inflammation. Regular antibiotics and antifungals do not alleviate the rash and topical steroids make the condition worse. What is the next step of treatment?
Dracunculus medinensis
Tx: niridazole
Patient presents with progressively worsening vision. PE reveals dark nodules on the skin of the arms and face. What is the mode of transmission and the treatment?
Onchocerca volvulus (African river blindness)
-black flies
Tx: Ivermectin
Patient presents with orbital pain and vision changes. PE reveals a worm crawling thru the conjunctiva. What is the treatment?
Loa loa
Tx: diethylcarbamazine
Patient presents with progressively enlarged right leg. Diagnosis of elephantiasis is made. What is the pathogenesis and treatment?
Wuchereria bancrofti
-worms invade lymphatic channels and block them
Tx: diethylcarbamazine
Patient presents with progressively worsening headaches. History reveals he had a rare-cooked pork chop earlier in the week that gave him an upset stomach. MRI reveals Swiss cheese appearance of the brain. What is the treatment?
Taenia solium (pork tapeworm)
Tx: mebendazole (for neurocysticercosis)
-if cysts aren’t in the brain use praziquantel
Patient presents with irritability and mood swings. He also reports being very fatigued and appears pale. CBC reveals megaloblastic anemia. History reveals he likes to eat freshwater fish. What is treatment?
Diphyllobothrium latum (fish tapeworm)
-depletes B12 vitamin store
Tx: praziquantel
Patient presents with hepatosplenomegaly along with hematuria. Liver biopsy reveals granuloma and fibrosis formation. What is a risk of chronic infection with this agent?
Schistosoma hematobium
-squamous cell carcinoma of the bladder
Tx: praziquantel
Patient presents with cough that produces rust colored sputum. Sputum culture reveals only normal flora and not gram (+) cocci. What is the treatment for the causative agent?
Paragonimus westermani
-undercooked crab meat, migrates to the lungs causing secondary bacterial infection leading to hemoptysis
Tx: praziquantel
