Chagas Disease

Excerpt

Chagas disease, or American Trypanosomiasis, is a potentially life-threatening zoonotic illness caused by the parasite Trypanosoma cruzi, first described in 1909 by Brazilian physician Carlos Chagas. The disease is primarily found in Central and South America, Trinidad, and the southern United States, with rural areas being most affected due to the presence of the reduviid bug (also known as the triatomine or "kissing bug"). The term kissing bug is a colloquial term that refers to a variety of species of insects in the Triatominae family (triatomines) that commonly seek out uncovered host mucosal surfaces and thus will frequently bite the face.

The vector-borne disease is transmitted primarily via contact with contaminated excrement of the reduviid bug into an open wound (eg, the bite of the bug itself), with the insect serving as the intermediate host for the parasite and humans and other mammals serving as definitive hosts. Vertical transmission between mother and fetus is also possible. Other modes of transmission include transfusion of blood products, transplant of an infected organ, or consumption of infected food or drinks.

Chagas disease has 2 phases: acute and chronic. The acute phase, lasting about 2 months, often presents with mild or no symptoms, though fever, localized edema, and Romana’s sign (unilateral eyelid swelling) may occur. In the chronic phase, which affects approximately 30% of infected individuals, cardiac complications, eg, cardiomegaly, heart failure, and arrhythmias, are common, while gastrointestinal involvement may lead to megacolon or megaesophagus. Diagnosis in the acute phase relies on microscopic detection of the parasite or PCR testing, while chronic cases are confirmed through serological tests.

Treatment includes antiparasitic medications, nifurtimox and benznidazole, which are most effective in the acute phase. In chronic cases, management focuses on treating complications, with some patients requiring pacemakers, defibrillators, or surgical interventions.