Human pathogenic viruses in waters of Lake Zarnowieckie (north Poland).

The objective of the study was to determine the occurrence of viruses pathogenic to man in the Lake Zarnowieckie and its neighbourhood that is in the area that was to be terminally polluted by the nuclear power-station built there. In 1990, the construction of the power-station was given up, and it will not be finished. In 1986-1989, water samples were periodically collected from a number of sampling points in the Lake Zarnowieckie, the Piaśnica river, and from the coastal water of the Baltic Sea. The total of 304 water samples were examined virologically, out of this number 51 (16.8%) showed a positive cytopathic effect in green monkey kidney cell culture GMK, indicating the presence of enteroviruses and adenoviruses. The isolated viruses were identified with the aid of serological neutralization reaction. Of the three types of enteroviruses, identified were: polio-serotypes 1, 2, 3--seven times (they were vaccine viruses probably, because poliomyelitis has almost been eradicated in Poland, the reported number of cases was from 0 to 4 annually), coxsackie B-2, 3, 4, 5 serotypes-20 times; ECHO-4, 5, 6, 7, 9, 11, 12 serotypes-22 times and adenoviruses-5 serotype-3 times. Obtaining viruses from the majority sampling points of the Lake Zarnowieckie testified for their wide spread in waters of the lake. Isolation of coxsackie B and ECHO in spring and autumn, and polio and adenoviruses in summer suggested the seasonal character of their occurrence. The presence of enteroviruses in the water coming from the sewage treatment plant proved their not complete inactivation during the treatment process.