L 89 African Sleeping Sickness, Chagas, Leishmaniasis Flashcards
What is the causative agent for african sleeping sickness and the vector?
Trypanosoma brucei gambiense (W Africa) T. brucei rhodesiense (E. Africa) Vector: Tsetse fly
What is one feature of trypanosomiasis that makes it hard for the immune system to keep up?
Antigenic switching
What parasite is pictured?
Trypanosoma spp
Causes African Sleeping Sickness
Patient presents with a skin lesion as shown with following LAD, fever, mental dullness, tongue tremors, paralysis, and somnolence. Disease?
This is a classic presentation for african sleeping sickness
Starts as a chancre and pregresses to parasitemia, LAD, and involves the CNS
CNS involvement and Somnolence only happen in the West Africa version of this disease caused by T. gambiense
Patient is in W Africa working in the humid jungles/forests and encounters pigs.
Later presents with skin chancres, metal dullness, fever, paralysis, sleepiness
Causative agent?
T brucei gambiense
Trypomastigotes found in the blood is diagnostic
Patient has been in Eastern Africa hunting game animals in dry savanna woodlands
Presents with a sore on the skin, LAD, fever, but no somnolence or CNS disorders
What is likely agent?
T brucei rhodesiense
African Sleeping Sickness
This is the acute version that moves fast enough to kill before causing CNS Sx
Patient lives in impoverished latin america, is a child, presents with fever, fatigue, myalgia, headache, rash, diarrhea, vomiting, enlarged spleen, LAD
Also presents with a swollen eyelid
Following found in blood
What is expected to be found in the tissues?
This is an example of Chagas disease which is the american form of trypanosomiasis. The agent is trypanosoma cruzi
Infective and early stage of the disease is the trypomastigote that is seen in the picture.
Later stages involve amastigotes in the tissues replicating in pseudocysts
The infection is spread by the kissing bug through posterior station
This is the acute phase that happens in kids. The chronic stage happens in adults.
Patient is from latin america and is an adult presenting with megacolon and a tissue biopsy shows pseudocysts as seen in the image.
This is the chronic form of Chagas disease or american trypanosomiasis. Caused by trypanosoma cruzi
Many people have it for decades and never know. The parasite seeks out cardiac and nervous tissue and replicates in pseudocysts and eventually damage the tissue leading to heart failure, megaesophagus, megacolon, stroke.
Can be spread by sex, transplacental, transmammary, transfusion, triatomid bugs
What was the gulf war parasite and how is it spread?
Leishmaniasis
Spread by the sand fly
Describe the life cycle of leishamaniasis
Infective stage is the promastigote
Becomes an intracellular amastigote–this is what causes the pathology
What are the agents that cause cutaneous Leishmaniasis?
L tropica–old world
L mexicana–new world
L braziliensis–new world
Patient presents with painless ulcerating skin leasions. Cells from the site show macrophages with an intracellular amastigate parasite. What are the likely agents?
This is the cutaneous form of leishmaniasis
The lesions are not painful unless they are secondarily infected by bacteria
Infective stage is the promastigote, but becomes an intracellular pathogen as an amastigote
Agents are L tropica, L mexicana, L braziliensis
Patient presents with deformity of the nose, mouth, skin. Lesions are painful. What is the disease and causative agent?
This is the mucocutaneous form of Leishmaniasis caused by L braziliensis
Involves the skin and mucous membranes
Causes cartilage destruction of the outh nose and other
Secondary bac infections can cause necrosis
Patient presents with skin leasions, fever, and parasites in macrophages, hepatosplenomegaly. Likely agent and disease?
This is the visceral form of Leishmaniasis–caused by L donovani, found in the middle-east
Initially patient will have skin lesions, but will spread to the organs causing HSM
Usually not fatal and sometimes asymptomatic
If not treated, a recurrence causes post Kala-Azar which is the condition in the image.
