Evolution of concentration and typing methods of waterborne viruses

The paralytic potential of the poliovirus was recognized as early as the 14 th century B. C. as illustrated in Egyptian art. But it is only after the four last decades that methods for their concentration from water and their identification were performed. Among several of them the adsorption-elutio n method was retained. Nevertheless two important barriers had to be ran-ov er The first one was the concentration-elution steps on different materials which had to be improved. The second one was the typing method which had t o move from particle by particle identification to entire viral population. Despite of these advances only a few cytopathogenic serotypes were found. The reverse transcriptase-polymerase chain reaction with its far more wide spectrum allows the first and direct identification of viral nucleic acids (or their fragments) of almost all viruses, cytopathogenic or not. With thi s method elevated amounts of drinking water samples were found positive for several non cytopathogenic viruses. The sanitary significance of these res ults has still to be proved.