Prevalence of cardiotropic viruses in adults with clinically suspected myocarditis in South Africa

OBJECTIVES: To determine the prevalence and types of viral pathogens in the myocardium of patients presenting with clinically suspected myocarditis in South Africa. METHOD: This is a prospective cross-sectional study. Consecutive adults presenting to a single tertiary centre in South Africa between August 2017 and January 2021 who fulfilled the European Society of Cardiology’s diagnostic criteria for clinically suspected myocarditis and who had undergone the appropriate investigations, including cardiac MRI (CMR) and endomyocardial biopsy (EMB), were included. RESULTS: One hundred and two patients with clinically suspected myocarditis were enrolled. Acute myocarditis (AM) was confirmed by CMR or EMB in 82 (80.39%) patients. Viral genomes were detected by PCR in EMB specimens of 50 patients with AM. Parvovirus B19 (PVB19) was the most frequently detected virus, in 37 as monoinfection and 4 as coinfection. This was followed by Epstein-Barr virus (n=6), human herpesvirus 6 (n=2) and human bocavirus (n=1). PVB19 was also detected in 9 patients with no evidence of AM on CMR or EMB. CONCLUSION: Viral myocarditis is the most common form of myocarditis in South Africa. Local viral prevalence appears to be similar those of the developed world. The clinical significance and pathogenic role of PVB19 remains questioned, and its local background prevalence will have to be further investigated.