Abstract
Exosomes are secreted nanovesicles that are able to transfer their cargo (such as miRNAs) between cells. To determine to what extent exosomes and exosomal miRNAs are involved in the pathogenesis, progression and diagnosis of viral infections. The scientific literature (PubMed and Google Scholar) was searched from 1970 to 2019. The complex biogenesis of exosomes and miRNAs was reviewed. Exosomes contain both viral and host miRNAs that can be used as diagnostic biomarkers for viral diseases. Viral proteins can alter miRNAs, and conversely miRNAs can alter the host response to viral infections in a positive or negative manner. It is expected that exosomal miRNAs will be increasingly used for diagnosis, monitoring and even treatment of viral infections.