Chapter 13 Recent Advances and Future Needs in Environmental Virology

The detection of viruses in water and other environmental samples constitutes special challenges. The standard method of detection of viral pathogens in environmental samples uses assays in mammalian cell culture. The infected cell cultures undergo observable morphological changes called cytopathogenic effects (CPEs) that are used for the detection of viruses. Even though many viruses are culturable in several cell lines and are thus detectable by the development of CPEs in cell culture, there are several viruses, like enteric waterborne adenoviruses types 40 and 41, which are difficult to culture and do not produce clear and consistent CPE. Other viruses, like waterborne caliciviruses, have not yet been successfully grown in cell cultures. Conventional cell culture assays for the detection of viruses in environmental samples have limited sensitivity and can be labor-intensive and timeconsuming. Two advances, the PCR and microarrays, have spurred the study of viruses and should be further applied to the field of environmental virology. The ability of both DNA viruses and RNA viruses to rapidly evolve means new and emerging viral pathogens will need to be addressed. Pathogen discovery and characterization, occurrence in the environment, exposure pathways, and health outcomes via environmental exposure need to be addressed. This will likely follow a new microbial risk framework that will require focused research on some important properties of viral disease transmission. The future will require models that examine community risks and provide explicit links between the models currently under development for environmental exposure and infectious disease.