Acute myocarditis and haemoptysis in an adult with human bocavirus monoinfection: a case report.

Background: Bocavirus monoinfection-related acute myocarditis is an aetiology that has rarely been described in the literature.

Case summary: A 36-year-old male, with no significant medical history, presented to the emergency department with a 4-day history of dyspnoea, haemoptysis, left-sided chest pain, and high-grade pyrexia. The initial investigations revealed a raised troponin T, raised C-reactive protein, and a normal electrocardiogram. A comprehensive microbiological and virological work-up (testing for 14 viruses and bacteria) detected human bocavirus (HBoV) DNA monoinfection. Cardiac magnetic resonance imaging showed left ventricular ejection fraction of 48%, with subepicardial late gadolinium enhancement. Other imaging modalities (chest X-ray, echocardiography, computed tomography pulmonary angiography, and bronchoscopy) revealed no other causative pathology. The patient was treated with anti-inflammatory medications and left ventricle remodelling therapy. He had a good clinical outcome. Moreover, a collateral history revealed that the patient's infant had presented with a severe respiratory illness, which was felt to be of viral aetiology, several days prior to the patient's own onset of symptoms.

Discussion: To our knowledge, this is the fourth case of HBoV-related acute myocarditis in an immunocompetent adult. This case also displays new clinical features for HBoV infection-haemoptysis, high-grade pyrexia, and a potential for vertical transmission from infants.