ENVIRONMENTAL VIROLOGY - FROM DETECTION OF VIRUS IN SEWAGE AND WATER BY ISOLATION TO IDENTIFICATION BY MOLECULAR-BIOLOGY - A TRIP OF OVER 50 YEARS

Environmental virology began with efforts to detect poliovirus in sewa ge and water more than 50 years ago. Since that time, cell-culture met hods useful for detection of enteroviruses have been replaced by molec ular biology techniques for detection of pathogens (hepatitis A and E viruses, caliciviruses, rotaviruses, and astroviruses) that do not gro w in cell culture or grow with great difficulty. Amplification of vira l nucleic acid using the polymerase chain reaction (PCR) is the curren t preferred method. PCR or RT-PCR (to detect RNA viral genomes) is rap id, sensitive, specific, and quantitative. Method shortcomings include potential inhibition by substances in some environmental samples and an inability of test results to distinguish between infectious and non infectious virus. Current questions involving use of PCR/RT-PCR tests for public health purposes include: What is the public health signific ance of a positive test, and should direct tests for viruses replace c urrent public health-monitoring programs?