Trypanosomiasis Flashcards
Where is Chagas found?
South America
NOT AFRICA
How is Chagas transmitted?
Kissing bug bites you and then poops in the bite
What an insult!!!
It can also be transmitted by blood transfusion, organ donation, oral, lab accidents, mother to fetus
Blood supply is screened for Chagas
What are the clinical manifestations of Chagas disease?
Acute disease: mostly mild flu like illness, hepatosplenomegaly, chagoma (indurated, erythematous lesion), Romañas sign (painless unilateral periorbital edema), rarely: myocarditis, meningoencephalitis
Indeterminate disease: no symptoms; 70% of patients remain like this
Chronic Chagas heart disease:
Chronic GI chagas disease:
When do you treat Chagas? What drugs?
Treat during acute infection
Benznidazole or Nifurtimox
What is the mechanism of action of benznidazole?
Side effects?
Nitroreduction intermediates bind parasite molecules
SE = dermatitis, peripheral neuropaty, anorexia, bone marrow suppression
What is the mechanism of action of nifurtimox? SE?
Acts through production of reduced oxygen metabolites
SE = anorexia, nausea, weight loss, tremors, insomnia, peripheral neuropathy
Why do you want to think twice before administering Chagas treatment?
The drugs have lots of bad side effects
You have to treat for 60-90 days!!
You have to get the drugs from the CDC
How do you diagnose acute chagas?
Blood smear with tryptomastagoes on it
Culture
PCR
Can you detect Chagas during the indeterminant form?
No – smear would be negative, PCR is unreliable, but you can use serology
But they can get reinfected during immunosuppression, pass on the disease to others by infecting the vector or via blood transfusion/ transplant, pass it on congenitally
What is the pathogenesis of cardiac disease due to Chagas?
Probably autoimmune process due to cross reactivity with the Chagas
You get fibrosis which blocks the conduction channel and leads to arythmias
You can also get thrombi leading to stroke
What is the pathogenesis of chronic GI due to Chagas?
Collagen –> thick walls of bowel that can’t perform peristalsis bc ganglion are destroyed
Esophagus: dysphagia, regurgitation, aspiration
Colon: chronic severe constipation, fecaloma, dilation of bowel
How do you diagnose chronic Chagas?
2 serologic tests
What do you do if you find out that a patient has chronic Chagas?
Tell them not to donate blood
Test their children
If normal physical/EKG - just watch them
If they have signs of cardiomyopaty - do a full heart workup
If they have GI symptoms – do a barium study
Treat <18 year old if they have chronic chagas
Who do you treat for Chagas?
Acute infection
Early congenital infection
Children <18 YO with chronic infection
Reactivation in immunosuppressed patients
Generally offered: Adults 19-50 without advanced cardiomyopathy
Gray area: Adults >50 YO without advanced cardiomyopathy
NEVER: pregnant or renal failure or advanced cardiomyopathy
What are the 3 groups of immunosuppressed that can get Chagas?
Patients who receive Chagas infected organs (112 days to develop flu like symptoms, decrease cardiac function)
Organ recipients who get reactivation (seems like a rejeciton episode+ panniculitis, skin nodules) – PCR to diagnose
HIV/AIDS patients - ring enhancing lesion in the brain (note that you’d think toxo, then lymphoma), myocarditis
