Week 7 Flashcards
diseases or parasites from border of Tanzania and Kenya that is continuous with the Serengeti National Park.
- ebola
- malaria
- a bunch of other parasites
Flu season in tropics
Flu season is all year round in the tropics, it is seasonal in the United States because in the winter season people are normally cramped together but he could have anything based on the symptomology.
gold standard for malaria diagnosis
- Thick and thin smears, and you are supposed to do three within 24hrs and read by a professional.
- Rapid diagnostic is not efficient because it gives false negatives.
- malaria prophylaxis reduces the likelihood of getting malaria but it is not 100%.
- Patient cannot miss doses( needs to be taken every day) and cannot be taken with milk because it contains calcium which binds to the doxycycline and makes the doxycycline ineffective.
treatment for malaria
- chloroquine but Malaria parasites can build resistance due antigenic variation
- drugs for malaria are highly toxic because they are anti-folate and antimetabolite drugs affect the body’s processes
- can give quinidine as IV. We could also give mefloquine but it has horrible side effects.
- don’t have vaccines for malaria parasites.
life cycle of Malaria
- anopheles mosquito bites human and injects sporozoites
- sporozite goes into liver cell, infects liver cell and becomes schizont
- shizont ruptures and becomes merozoites is released into blood and gets into erythrocyte where it undergoes asexual multiplcation, becomes immature trophozite becomes mature trophozite (diagnostic) and cell becomes schizont–schizont ruptures and continues to affect more erythrocyte
- immature trophozoite (diagnostic) can also become gametocytes in the erthyrocyte (female/male)
- the gametocytes can then be taken up by mosquitos when they bite human
- gametocyte then turns into exflagellated microgametocyte and matures into macrogametocyte then becomes ookinete which turns into oocyst and then releases sporozoites (infectious form)
- infection starts when the oocyte raptures
Can you treat parasites if they are intracellular?
-yes because you can target the different stages of the life cycle.
Treatment for malaria
malaria parasites can stay in the liver for a long time before becoming infectious. The drug that is normally given when the parasites gets to the liver is primaquine and we normally check your G6PD before giving it because primaquine can cause hemolytic anemia in people with G6PD deficiency.
Sleeping sickness
- caused by T. b. gambiense or T. b. rhodesiense
- confirm diagnosis with Lumbar puncture, needs to get one to make sure they don’t have the parasites in the CSF, peripheral blood smear, and we can also get a sample from the chancre.
- cant tell if it is gambiense or rhodesiense until we know what location he was when he got infected
- vector is Tsetse fly. It was called the savior of African wild life because it killed the livestock of the warmongers from Europe when they got to the tsetse fly belt.
- presents with nodule on his neck
Tsetse flies
-attracted to color blue but like to land on black because most of the livestock they feed on are black colored
Life cycle of sleeping sickness
-Tsetse fly takes blood meal and injects metacyclic trypomastigotes into lymph
which gets into blood stream becoming bloodstream tryptomastigotes and multiply by binary fission.
-tsetse fly takes a blood meal and blood stream trypomatigotes are injested and then become pro-cyclic trypomastigotes in tsetse midgut; multiply by binary fission
- pro-cyclic trypomastigotes leave midgut and transform into epimastigotes which multiply in salivary gland bybinary fission then become metacyclic trypomastigotes again
toxoplasmosis
- Cat poop can contain the parasite
- Undercooked meat
- Can cross placenta
TORCH
-Toxoplasmosis
-Other: syphilis, varicella-zoster, parvovirus, zika
-Rubella
Herpes, HIV
toxoplasmosis life cycle
- unsporolated oocysts shed in cat feces (sporolate in the environment after 1-5 days and become inefective)
- oocysts transform into tachyzoites after ingestion which localize in neural and muscle tissue and develop into tissue cyst bradyzoites
- cats become infected after consuming intermediate host (birds/rodent) or by directly ingesting sporulated oocysts in the envrionment
- humans can become infected by eating undercooked meat of animals harboring the tissue cysts, consuming food/water contaminated with cat feces or by contaminated environmental supplies, blood transfusion/ organ transplantation, transplacentally from mother to fetus
- in human host parasites parasite forms tissue cysts most commonly in skeletal muscle, myocardium, brain and eyes which remain in host for the rest of their life.
Hantavirus
-found in the poop and urine of rats
Chagas (America trypanosomiases)
- caused by the T. Cruzi
- vector is the reduviid bug also called the kissing bug because it bites the lips and are found throughout Texas which means it is endemic.
- disease is normally asymptomatic most of the time
- order to cause an infection the bug bites, feeds and then defecates into the hole it made. When you scratch that site you get the infection.
- can cure chagas before it becomes a problem
