Chagas Disease: What U.S. Clinicians Need to Know - Glossary

Achalasia – Failure of the lower esophageal sphincter to relax. If chronic, can lead to dilatation and eventually megaesophagus

Acute phase – The first approximately 8 weeks after Trypanosoma cruzi infection, characterized by high levels of circulating parasitemia detectable by peripheral blood microscopy

Autochthonous infection – Originating locally; for example, "autochthonous Chagas disease in the United States" usually refers to Trypanosoma cruzi infection acquired through vectorborne transmission within the United States

Benznidazole – A nitroimidazole derivative, one of two drugs with proven efficacy to treat Trypanosoma cruzi infection

Chagoma – Raised nodule or swelling at the site of inoculation of Trypanosoma cruzi through the skin

Chronic phaseTrypanosoma cruzi infection beginning 60 - 90 days after initial infection, and in the absence of successful treatment, lasting for the rest of the individual's life. Characterized by very low levels of circulating parasitemia undetectable by peripheral blood microscopy

Determinate form – Chronic Trypanosoma cruzi infection with signs and/or symptoms consistent with chronic Chagas heart or digestive disease

Enzyme Linked Immunosorbent Assays (ELISA) – Any enzyme immunoassay utilizing an enzyme-labeled immunoreactant (antigen or antibody) and an immunosorbent (antigen or antibody bound to a solid support)

Immunofluorescent Antibody Tests (IFA) – Any immunoassay using fluorochrome-labeled antibody or antigen

Indeterminate Form – Chronic Trypanosoma cruzi infection with no signs or symptoms suggestive of Chagas cardiomyopathy or gastrointestinal disease

Kissing bug – Alternative terminology sometimes used to refer to the triatomine bug

Nifurtimox - A nitrofuran compound, one of two drugs with proven efficacy to treat Trypanosoma cruzi infection

Reservoir host – The host animal (human or non-human) in which the population of an infectious agent is maintained, allowing the transmission cycle to be sustained over time. The agent may or may not cause disease in the reservoir host. In the case of a vectorborne disease, the reservoir host is demonstrably infectious to the vector

Polymerase Chain Reaction (PCR) – An in vitro technique for rapidly synthesizing large quantities of a given DNA segment that involves separating the DNA into its two complementary strands, binding a primer to each single strand at the end of the given DNA segment where synthesis will start, using DNA polymerase to synthesize two-stranded DNA from each single strand, and repeating the process

Protozoan – Any of a phylum or subkingdom (Protozoa) of chiefly mobile and heterotrophic unicellular protists that are represented in almost every type of habitat and include some pathogenic parasites of human and domestic animals

Romaña's sign – Unilateral bipalpebral edema resulting from the inoculation of Trypanosoma cruzi via the conjunctiva

Triatomine bug - A blood-sucking insect that feeds on humans and animals

Trypanosoma cruzi – Protozoan parasite of the order Kinetoplastida and the family Trypanosomatidae, the causative agent of Chagas disease

Vector - Any agent (person, animal, or microorganism) that carries and transmits a disease

Vectorborne transmission - Transmission of an infectious agent that occurs when a vector bites or touches a person