Myocarditis is primarily caused by what type of infection?

Myocarditis is primarily associated with viral infections, which is why selecting "viral infection" is the most accurate response. Various viruses are known to cause this inflammation of the heart muscle, with the most common being the Coxsackievirus, among others like the influenza virus and the adenovirus.

While bacterial and fungal infections can also affect the heart, their contribution to myocarditis is significantly less common. Bacterial infections typically lead to other conditions such as endocarditis, while fungi are more often associated with systemic infections in immunocompromised individuals. Thus, while multiple infectious agents can impact heart health, the primary cause of myocarditis is indeed viral, making this selection the most correct in the context of this question.