Chagas disease: The essential role of laboratory diagnosis.

Abstract

Chagas disease is an infectious illness caused by the protozoan Trypanosoma cruzi, transmitted mainly by insects of the subfamily Triatominae. It is characterized by acute and chronic phases, the latter often being asymptomatic for long periods. Laboratory diagnosis is one of the main challenges in addressing the disease, due to the parasite’s genetic diversity, the different routes of infection, and the variation in parasitic load throughout the clinical stages. This article aims to review the main laboratory methods used in the diagnostic routine of Chagas disease. Direct parasitological techniques, such as thick blood smear, microhematocrit, and Strout, commonly applied during the acute phase, are discussed; as well as serological methods, including ELISA, indirect immunofluorescence, and hemagglutination, which are indicated for the chronic phase; and molecular techniques, such as polymerase chain reaction (PCR), in addition to rapid tests. The review indicates that although technological advances have improved diagnostic sensitivity and specificity, there are still limitations regarding accessibility, laboratory infrastructure, and the need for confirmation by multiple methods. It is concluded that the integration of different diagnostic approaches is essential for early detection of infection, enabling appropriate treatment and contributing to disease control, especially in endemic areas and vulnerable populations.