100 - Trypanosomiasis

Abstract

American Trypanosomiasis (Chagas disease)•First Described: Chagas disease (American trypanosomiasis) was first described in humans in 1909 by Dr. Carlos Chagas.1 The first canine Chagas disease cases in the United States were diagnosed in the early 1970s in Texas.2•Cause: Trypanosoma cruzi, a protozoan parasite (order Kinetoplastida, family Trypanosomatidae).•Affected Hosts: Dogs, cats, humans, horses, nonhuman primates, and other domestic and wild mammalian species.•Geographic Distribution: Endemic across the Americas including South and Central America, Mexico, and the southern United States.•Mode of Transmission: Contact with infected feces from, or ingestion of, triatomine (kissing bug) vectors, primarily Triatoma species. Transmission through blood transfusion and vertical transmission can occur.•Major Clinical Signs: Infected dogs may be subclinically infected. Clinical disease manifests as lethargy, inappetence, mucosal pallor, lymphadenopathy, splenomegaly, arrhythmias, heart failure, or sudden death. Neurologic signs such as pelvic limb ataxia and exaggerated spinal reflexes may also occur.•Differential Diagnoses: The differential diagnoses for suspected Chagas myocarditis include dilated cardiomyopathy, parvoviral myocarditis in puppies, canine monocytic ehrlichiosis, babesiosis, and leishmaniosis. The primary differential diagnoses for suspected Chagas meningoencephalitis in puppies are CDV infection and neosporosis, but other infectious and inflammatory causes of meningoencephalitis should also be considered.•Human Health Significance: Chagas disease is a neglected tropical disease with as many as 8 million humans infected. Infected animals may be sentinels for human disease risk when there are infected triatomine vectors in the environment. Direct transmission from infected dog to human has not been shown. Transmission to humans has the potential to occur after needle-stick injuries; caution is advised when handling tissues or clinical specimens from dogs with suspected trypanosomiasis.