Box 2.

Causes of myocarditis

Infectious causes
Viral, eg adenoviruses, enteroviruses (including coxsackieviruses), parvovirus B19, influenza, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HIV-1
Bacterial, eg Mycoplasma pneumoniae, Spirochaetes (including Treponema pallidum and Borrelia burgdorferi), Staphylococcus spp. and Streptococcus spp.Fungal, eg Aspergillus spp. and Candida spp.
Protozoal, eg Plasmodium spp. and Toxoplasma spp.
Helminth, eg Schistosoma spp. and Toxocara spp.
Rickettsial (and Rickettsia-like organisms), eg Rickettsia rickettsiae and Coxiella burnetii (a Rickettsia-like organism)
Non-infectious causes
Hypersensitivity/Allergic, eg antibiotics, anticonvulsants and various vaccines
Systemic inflammatory disorders, eg sarcoidosis, systemic lupus erythematosus, thyrotoxicosis (eg Graves’ disease), diabetes mellitus (insulin dependent), inflammatory bowel disease and granulomatosis with polyangiitis
Toxic myocarditis, eg amphetamines, cocaine, bites/stings, catecholamines, radiation, chemotherapy and immune checkpoint inhibitors
Transplant rejection, eg heart transplantation and stem cell transplantation
Autoreactive, eg giant-cell myocarditis and lymphocytic myocarditis