Domestically Acquired Leptospirosis Complicated by Myocardial Involvement: A Case Report from Japan.

Leptospirosis can cause myocardial involvement that mimics viral myocarditis. We herein report the case of a 77-year-old man without a history of overseas travel who presented with flu-like symptoms, elevated inflammatory marker levels, and an impaired cardiac function. As acute myocarditis was suspected, the patient was transferred to a tertiary care center, where leptospirosis was diagnosed. Antimicrobial therapy was initiated, and the patient's condition improved. Myocardial involvement associated with leptospirosis should be considered in selected patients. This case highlights the importance of assessing the cardiac function during clinical evaluation.