American Trypanosomiasis
American Trypanosomiasis or Chaga’s disease is caused by Trypanosomiasis cruzi, a protozoan parasite found only in the America; infects wild animals and to a lesser extent humans from southern South America to the southern United States.
An estimated 10-12 million people are infected, mostly in rural areas, resulting in about 45,000 deaths annually.
The disease is often acquired in childhood. In many countries in South America, Chaga’s disease is the most important cause of heart disease.
T. cruzi, is transmitted by reduviid (triatomine) bugs infected by ingesting blood from animals or humans who have circulating trypanosomes.
Multiplication occurs in the ingesting tract of the bug and infective forms are eliminated in feces.
Infection in humans occurs when the parasite penetrates the skin through the bite wound mucous membranes or the conjunctiva.
Transmission can also occur by blood transfusion or in utero. From the blood stream, T. cruzi invades many cell types but has a prediction for myocardium, smooth muscle and CNS glial cells.
Multiplication causes cellular destruction, inflammation, and fibrosis with progressive disease over decades.
Symptoms
The acute stage is seen principally in children and last 1-months. The earliest findings are at the site of inoculation either in the eye – Romana’s sign (unilateral edema, conjunctivitis and lymphadenopathy) – or ion the skin or a chagoma (selling with the local lymphadenopathy).
Subsequent findings include fever, malaise, headache, mild hepatosplenomegaly, and generalized lymphadenopathy.
Acute myocarditis and meningoencephalitis are rare but can be fatal.
American Trypanosomiasis
