Operating conditions for using oiled sodocalcic glass wool (Saint Gobain R. 725) to concentrate enteroviruses in 100 to 1000 liters samples were determined. These filters recovered from 62 to 75% of several enteroviruses (laboratory strains or field isolates) and rotavirus SA11 that were added to tap water. The technique permitted the recovery of 62% and 57% of poliovirus added respectively to river water and treated waste water. The results of a 44 months survey of the Seine and Mame river waters are reported. Being efficient at ambient pH, the use of glass wool may permit continuous virological monitoring of water samples.

Coastal areas are frequently contaminated by microorganisms of human origin, due to high population density and low seawater renewal. To evaluate the impact of wastewater input on shellfish quality, a study was conducted in Brittany (France) over a period of 20 months. A hydrodynamic model was used to simulate wastewater impact on microbial water quality. To validate the model, wastewater from the three main sewage treatment plants and shellfish from three sites were sampled monthly. Bacterial indicators (E. coli), F-RNA phages were searched for by culture and noroviruses by RT-PCR and hybridisation. These microorganisms were detected in the three effluents and clams, with no marked seasonal variation. The microbial concentrations in the two oyster beds, distant from the effluent outfall, were low, and only three of the samples were positive for norovirus. For simulation, the winter wastewater inputs of E. coli and phages were calculated and an estimation for norovirus flux was made from the epidemic situation in the population. The microbial behaviour was included in the model by a decay-rate factor. Results from the model calculations were found to be very similar to E. coli and phage concentrations observed in shellfish. For noroviruses, the model indicated that shellfish distant from the wastewater input were under the detection limit of the RT-PCR method. This study demonstrated the use of modelisation to interpret norovirus contamination in various areas.

This study was initiated by the AFNOR water microbiology working group to evaluate the performance of the glass wool method for virus recovery. Its reliability was tested with drinking and sea water by respectively nine and thirteen laboratories. In both trials, six were actively involved in water virology research, one was designated as a central laboratory, the others had no experience in virological practices. Analysis of reproducibility and repeatability according to NF-ISO 5725-2 were realized. For drinking waters (24 assays), the average recovery efficiency was 72%, mean standard deviations: repeatability 12.4%; reproducibility 33.6%; inter-laboratories 21%. For sea waters (39 assays), the average recovery efficiency was 75% and the mean standard deviations 6.9%, 17.9% and 11% respectively.

Investigations were undertaken on the antiviral action of an hydroalcoholic extract from Haemanthus albijlos bulb, reported here as an efficient agent against RNA viruses. Poliovirus propagated on HeLa cells with different concentrations of the extract was used in the assays. The effect on cellular RNA, DNA and protein synthesis as well as on viral RNA synthesis was evaluated by measuring the radioactivity incorporated using labelled precursors.A 0.2 pL/mL concentration of the plant extract showed an inhibition of cellular RNA, DNA and protein synthesis compared with the control of 44%, 40% and 52%, respectively. At the same concentration a 90% decrease of the viral RNA synthesis was observed over 210 min.

A double reconcentration procedure was developed for virus detection in tapwater concentrates obtained by conventional adsorption-elution techniques suitable for cell inoculation as well as for genomic amplification. Using 7.5% PEG 6000 and 2.5% NaCl, a 15min contact time under agitation at room temperature followed by centrifugation (first step: 3,500xg, 90min, 4°C; second step 10,000xg, 20min, 4°C) were the conditions to obtain overall average virus recovery efficiencies of 71% for poliovirus from 900ml eluates and 88, 83 and 75% for poliovirus, coxsackie B2 and rotavirus respectively (400ml eluates). Direct extraction of viral RNA from the first PEG pellet with TrizolTM was efficient for RT-PCR assays without any further treatment. Primer pairs were selected to amplify rotavirus group A and poliovirus in seeded tapwater concentrated by adsorption elution through glass wool. A positive signal was obtained for theoretic virus concentration of 1 PFU. Analysis of field samples (1001) by cell culture and genomic amplification resulted in a higher sensitivity with the latter.