Closed-circuit system for the depuration of mussels experimentally contaminated with hepatitis A virus

In Italy, the consumption of raw or slightly cooked mussels represents the most important risk factor for the transmission of hepatitis A virus (HAV). Although there exist effective methods for the bacterial depuration of con taminated mussels, these methods are poorly effective on enteric viruses. T he objective of the present study was to evaluate the effectiveness of a cl osed-circuit depuration system that uses both ozone and UV light for disinf ecting water and that allows salinity and temperature, important parameters for the metabolism of mussels (Mytilus galloprovincialis), to be maintaine d at constant levels. The results showed that this depuration method decrea sed the viral load (from 1.72 log 50% tissue culture infective dose [TCID50 ] ml(-1) to <1 log TCID50 ml(-1) within 24 h and from 3.82 log TCID50 ml(-1 ) to <1 log TCID50 ml(-1) within 48 h). However, in both cases, after 120 h of depuration, a residual amount of virus capable of replicating in cells was detected. These results show that depuration, even if performed with ad vanced systems, may not guarantee the absence of virus.