Download Document

American Trypanosomiasis
Course of Infection
• There are three phases.
American Trypanosomiasis
Course of Infection
• Phase I. Trypomastigotes in peripheral
circulation.
– Edema at site of bite (often eye and cheek): if
on other area of the body than local
inflammation produces a small red nodule
(Chagoma) which is a swelling of the
regional lymph node.
– Headache, fever, prostration.
American Trypanosomiasis Course of
Infection
Romaña’s Sign
American Trypanosomiasis
Course of Infection
• Phase II. Trypomastigotes enter cells.
– Symptoms of phase I subside or become
absent.
American Trypanosomiasis
Course of Infection
• Phase III. Amastigotes within cells.
– Almost any cell can be invaded; however
they most commonly invade cells of the
reticuloendothelial system in the spleen and
liver, and cardiac, smooth and skeletal
muscles, additionally the nervous system
may be infected.
American Trypanosomiasis
Course of Infection
• Phase III. Amastigotes within cells.
American Trypanosomiasis
Course of Infection
• Phase III. Amastigotes within cells.
– Edema: abnormal accumulation of fluid in
the tissue spaces (cellular level)
– Inflamed lymph glands
– Enlarged spleen and liver (hyperplasia)
Pathology of Trypanosoma cruzi
Chronic phase - occurs
in adults.
Apex of heart usually
becomes very thin.
Impulses into
ventricles are affected.
American Trypanosomiasis
Course of Infection
• Phase III. Amastigotes within cells.
– Heart muscles:
• Fibers separated, inflamed
• Fibers weakened/ myocardial dysfunction
 (irregular heartbeat)
• Invasion of connective tissue which will
cause an enlarged heart
• Nerve ganglia destroyed/ cardiac arrest
Pathology of Trypanosoma cruzi
• Megaesophagus and Megacolon.
Pathology of Trypanosoma cruzi
• Megaesophagus and Megacolon.
• Muscle tone and peristalsis is destroyed.
Pathology of Trypanosoma cruzi
• Megaesophagus and Megacolon.
• Muscle tone and peristalsis is destroyed.
• Organs increase their diameters
greatly.
Pathology of Trypanosoma cruzi
• Megaesophagus and Megacolon.
• Muscle tone and peristalsis is destroyed.
• Organs increase their diameters greatly.
• Victim may not be able to swallow
and dies from starvation.
Pathology of Trypanosoma cruzi
•
•
•
•
Megaesophagus and Megacolon.
Muscle tone and peristalsis is destroyed.
Organs increase their diameters greatly.
Victim may not be able to swallow
and dies from starvation.
• Feces not formed effectively.
Pathology of Trypanosoma cruzi
Diagnosis
• Demonstration of trypanosomes in blood,
but this is very difficult.
• ELISA
• Xenodiagnosis
Xenodiagnosis
Prognosis and Epidemiology
• Not Good!! No effective treatment!
• 12-19 million people infected in the early
1990’s in Central and South America!
• Currently about 25% of people are
infected in Latin America!
Prognosis
• Not all people die from it!
• Children have acute cases and within a
month die.
• Adult infections are more chronic.
– Have shorter life span
– 30% die!
• Other Trypanosomes!
Hi There How are You!!!
Trypanosoma equiperdum the
causative agent of Dourine
Transmission
Symptoms
Trypanosoma evansi causative agent of
Surra or Murrina
This one is Mechanically Transmitted
Amphibians have trypanosomes!
DESSEROBDELLA PICTA feed
on salamanders and frogs
ANNELIDA: HIRUDINOIDEA DESSEROBDELLA PICTA
COLLECTED IN NEBRASKA
Calling and satellite male western chorus frogs.
True love. Male and female western chorus
frogs in amplexus.