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!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.

True love. Male and female western chorus frogs in amplexus.