Wednesday, October 10, 2007

Scalars and Vectors

In between first and second year, you "volunteer" down in South America, scaling mountains, trekking through rainforests, tanning on beaches, and mingling with the locals. You spend your spare time volunteering in a clinic. One day, this child walks in:

Your language skills aren't too good, but you gather that something might have bit him. A bug or fly maybe? You figure this might be important information, so you have the child draw what he saw. This is what he draws:

Hmm...not bad. You examine the boy more closely. The pertinent finding is his right eye, where he says the bug bit him. He has no other symptoms, but you're a little worried. You draw some blood and see this with a special stain:

Challenge: If left untreated, this patient may develop a cardiac manifestation of the disease. What would that be?

Related Questions:
1. What is the finding in the first image?
2. What is the bug in the second image?
3. What is seen in the third image?
4. What is the diagnosis?

All images are in the public domain.


Alex said...

easy.. chagas disease.. from the kissing bug which holds the tryp pathogen. watch out for heart problems!!!

Anonymous said...


Craig said...

Scalars and Vectors

The first image shows an acute infection with swelling of the right eye. This is a chagoma. He shows Romana's sign: unilateral periorbital edema, conjunctivitis, and preauricular lymphadenitis. The second image shows the vector insect Triatoma infestans, also known as the Kissing Bug. The third image shows Trypanosoma cruzi parasites, stained with a Giemsa stain. This is the pathogen of Chagas' disease or American trypanosomiasis. Chronic infection with Chagas' disease can lead to cardiomyopathy.

Source: Wikipedia

-Leish isn't a bad guess, but that's transmitted by sandflies and there would be splenomegaly.