In the early 1900’s, Dr. Chagas evaluated a girl who had lymphadenopathy and fever. Her blood smear showed the presence of trypanosomes. He used her blood to infect an animal, and the disease was duplicated. Hence the appellation attaching his name to the disease is appropriate.
Generally seen in warmer countries with lower income, the reduviid bug comes out at night and bites the victim on the mouth or face (thus the term “kissing bug”). The painless bite allows the female bug to suck blood, then defecate, releasing the protozoan parasite that she has been housing in her GI track, Trypanosoma cruzi, into the wound. When the eyelid is bitten, or the reduviid defecates into the eye, the victim rubs the infected wound or eye, and the unique finding of unilateral palpebral edema, Romaña’s sign, develops.
Usually, other than an itch at the bite area, the situation remains dormant for a few weeks. Then as the parasite sets up housekeeping and matures in the infected cells, the cells burst, releasing the parasite into the bloodstream, infecting lymph nodes, GI track, liver, spleen, and sometimes the heart. Patients who are immunocompromised are particularly susceptible to acute symptoms. The excellent review in April’s Pediatrics in Review, Congenital Chagas Disease, by Edwards et al, elaborates on this (10.1542/pir.2022-005545).
Since the disease is prevalent in Mexico and Central and South America, should the US or European pediatrician worry? Yup. The ingress of the migrant population, usually with lower income, from the South carries with it a guaranteed presence of some patients with Chagas disease. The reduviid bug itself is migrating to our southern borders. The trypanosome protozoan parasite can be transmitted through blood products or transplanted tissue, and there is maternal–fetal transmission as well. Many animals, including dogs, can be infected. Patient-to-patient transmission can happen but is uncommon.
Another real concern is that 2–3 decades later, cardiomyopathy and ventricular tachydysrhythmias can happen, usually sudden and fatal. Dilation of the esophagus and lower GI track can also occur, and thus, the disease must be recognized in the young and treated before the chronic phase happens; this is great unless a new teen or young adult who was previously infected is new to our clinical system.
The bottom line is that we must read and reread the Edwards et al article, learn about Chagas disease, and be ready to recognize and treat it. Otherwise, it will bite you.