Cryptosporidium-Induced Myocarditis: A Unique Case Study

Myocarditis is the inflammation of the myocardium. While viral infections commonly cause it, we present a unique case of <i>Cryptosporidium</i>-induced myocarditis in an immunocompetent individual. A 33-year-old man presenting with acute chest pain and loose stools was found to have troponin levels of over 1,000 ng/L. Initial viral screen tests were negative, and an inpatient echocardiogram showed an insignificant rim of pericardial effusion. Computed tomography of the coronary arteries showed no evidence of coronary artery disease. He was later discharged with outpatient cardiac magnetic resonance imaging (MRI), which subsequently showed acute focal sub-epicardial fibronecrosis, consistent with acute myocarditis. Following this, stool cultures were found to be positive for <i>Cryptosporidium hominis</i>, a protozoan parasite. After a further review of the history, it was discovered that the patient had recently been exposed to dead pigeons and faeces at a workplace construction site. This rare presentation demonstrates the importance of considering less common infectious agents even in immunocompetent patients, as there is only one other case study ever published. Furthermore, it highlights the increasing value of using cardiac MRI as a non-invasive investigation for myocarditis.