Toxoplasmosis
- Caused by toxoplasma gondii
- Widespread infection causing flu-like symptoms
- Reactivated in immunocompromised
- Transplacental transmission leads to serious problems
- Intracellular parasite that can infect any cell
Transmission of toxo among animals
- Transmission from contaminating oocysts (cats) - come from birds or rats getting eaten by cats who get the tissue cysts, and then comes out as a fecal oocyst
- Eating improperly cooked meat, transfusions, etc.
Essentially you can either get the tissue cysts or fecal oocysts
If someone is seropositive for toxo long before getting pregnant, is the baby at risk for toxo?
No you should have immunity against toxo, and so the baby should be protected.
If the maternal infection of toxo is
Probably not, the risk is pretty high
If maternal infection of toxo occurs during the first trimester, what disease of the neonate is possible?
- miscarriage
- stillborn
- chorioretinitis, hydrocephalus, intracranial calcifications, hepatosplenomegaly, jaundice, fever, anemia
If maternal infection of toxo occurs during 3rd trimester, what might happen?
- baby will be asymptomatic at birth but may have more learning disabilities and neurological sequelae
Can you directly identify toxo?
No, it’s pretty difficult. Do serology and PCR
Prevention of toxo
- No vaccine
- Change litter daily if you own a cat
- Keep cat indoors
- Dont eat undercooked meat
Tachyzoites vs. Bradyyzoites
- Tachy = dividing forms in a cell
- Brady = dormant forms in a cell
Chagas disease
- Infection that causes an acute and chronic phase
- Caused by trypanosoma cruzi
- There is a blood and tissue form
- Transmission = via kissing bug bite, congenital, blood transfusion, organ transplant
Life cycle of Chcagas
- You or dog is infected
- Bloodstream form gets transmitted to kissing bug
- Kissing bug feeds on human - bites you and then poops so that when it itches and you scratch, you scratch the parasites into the open wound (almost all other vectors use saliva)
- Gets into blood - travels to muscle cells (heart and intestine are its favorites)
Acute Chagas presentation
Initially mild symptoms at site of inoculation and in blood phase (often asymptomatic)
Chronic Chagas presentation
Asymptomatic tissue phase in most, but 20-30% will develop heart abnormalities and dilated esophagus or colon (die of heart attack)
Triatomine
Kissing bug
What’s the problem with a serological test for Chagas?
Doesn’t tell you if you are actively infected, or if you have any of the muscle form.
Why is chronic Chagas harder to diagnose?
Trypomastigotes are not found in blood and so you have to do a biopsy or some faulty serology
How to prevent Chagas
Don’t get bitten and pooped on.
- Feed at night
- Bugs breed in the cracks of poorly constructed homes
- Spray the houses
Leishmaniasis
3 types = cutaneous, mucocutaneous, visceral
- caused by Leishmania
- Intracellular parasite of macrophages (phagolysosome is a happy living place for them)
- Transmission: bite from sand flies or cutaneous contact
Life cycle of Leishmaniasis
Sand flies bite someone infected –> macrophage bursts and amastigotes transform into promastigotes, and then sand fly bites you and gives you the promastigotes. These go visceral to the spleen or cutaneous
Clincal presentation of the forms of Leishmaniasis
- Cutaneous - skin lesions/ulcers
- Mucocutaneous - partial or total destruction of mucous membranes of the nose, mouth and throat
- Visceral - irregular bouts of fever, weight loss, enlargement of spleen and liver
Diagnosis of Leishmaniasis
ID of parasites within cells in a biopsy
- rRNA its PCR
Best way to prevent leishmaniasis
People should sleep under bed nets, and the bed nets should be impregnated with an insectiscide
African sleeping sickness
Trypanosomiasis (tsetse fly vector)
- Hemoflagellate parasites
- Daylight biters, and can fly long ways
- Multiply in blood stream and can eventually enter CNS
Presentation of trypanosomiasis
- Wasting with fever, severe headaches, irritability, fatigue, lymph nodes, aching muscles and joints
