Why can myocarditis be considered an infectious disease?

Myocarditis, or inflammation of the heart tissue/muscle, is not an infectious disease but its causes can be. Myocarditis is really more of a symptom-the result of the infection. Most common infectious causes of myocarditis are viral though there are bacteria, like stapylococcus and diptheria, which can cause it. Myocarditis can also occur in other non-infectious entities like autoimmune disease, sarcoid and even pregnancy.