A detailed understanding of asymptomatic chronic viral infections is critical to analyse their pathogenesis,
assess the severity and burden of disease and, where required, optimize public health control
measures. Recent studies on herpesviruses showed that the hostevirus interactions are modulated by coinfections,
emphasizing the relevance of co-infections in determining the clinical expression (from
asymptomatic to symptomatic infections) and the severity of herpesvirus-associated diseases (either
neoplastic or infectious diseases). To demonstrate causality between viruses (virome) and diseases,
Koch's postulates should be adapted adding new knowledge on hostemicrobe relationship and microbial
interactions. In the present review we aim to provide an update on asymptomatic chronic infections and
criteria for causality and on the virological, immunological and hostevirus interactions in asymptomatic
chronic infections in human hosts, focusing on herpetic infections
