ECG manifestations of the biggest outbreak of Chagas disease due to oral infection in Latin-America.

Background: Chagas disease affects more than 15 million people worldwide. Although vector-borne transmission has decreased, oral transmission has become important. Recently, our group published the clinical and epidemiological characteristics of the largest outbreak of orally transmitted Chagas disease reported till date. Objective: To describe electrocardiographic changes occurring in the study population during the outbreak caused by ingestion of contaminated guava juice. Methods: We evaluated 103 positive cases, of which 76 (74%) were aged <= 18 years (average age: 9.1 +/- 3.1 years) and 27 (26%) were aged > 18 years (average age: 46 +/- 11.8 years). All patients underwent clinical evaluations and ECG. If the patients had palpitations or evident alterations of rhythm at baseline, ambulatory ECG monitoring was performed. Results: A total of 68 cases (66%; 53 children and 15 adults) had ECG abnormalities. Further, 69.7% (53/76) of those aged <= 18 years and 56% (15/27) of those aged > 18 years showed some ECG alteration (p = ns). ST-T abnormalities were observed in 37.86% cases (39/103) and arrhythmias were evident in 28.16% cases (29/103). ST alterations occurred in 72% of those aged <= 18 years compared with 19% of those aged > 18 years (p < 0.0001). Conclusion: This study reports the largest number of cases in the same outbreak of acute Chagas disease caused by oral contamination, with recorded ECGs. ECG changes suggestive of acute myocarditis and arrhythmias were the most frequent abnormalities found.