Adenovirus infections: new insights for the clinical laboratory

Since their discovery in 1953, research on human adenoviruses (HAdVs) has had diverse foci, resulted in groundbreaking discoveries, such as gene splicing, and generated powerful oncolytic constructs and expression vectors for vaccine development and gene therapy. In contrast, virologists working in this field have made relatively little progress toward the prevention and treatment of the wide spectrum of HAdV-associated diseases. The understanding of species-specific features of viral pathogenesis, or of the mechanisms underlying the establishment of latency and reactivation, is still limited. This group of viruses currently comprises 7 species, 51 serotypes, and 116 unique genotypes. This complexity manifests with a challenging pathophenotypic diversity. Some types are highly virulent, and others do not seem to cause disease in immunocompetent hosts. The assessment of viral load in blood and respiratory specimens has well-acknowledged clinical utility, but the lack of virus typing capabilities easily implementable in clinical laboratories represents a lingering major limitation to the interpretation of positive tests. Some HAdV infections do have severe consequences for both immunocompetent and immunocompromised patients, and the understanding of why this is the case will require more research. Clinical isolates and collections of positive specimens can provide unique resources to investigate the molecular bases of viral virulence and fitness and also help gather information of spatial-temporal patterns of viral circulation in susceptible communities, but they are extremely scarce. Clinical laboratories are underutilized interfaces between patients and academic scientists and have, therefore, a high potential to become valuable collaborators in research moving forward.