HEPATITIS-A VIRUS AND POLYMERASE CHAIN-REACTION AMPLIFICATION - METHODOLOGY AND RESULTS

Hepatitis A infection among patients receiving solvent/detergent inact ivated factor VIII preparations in various locations in Europe have be en documented recently. In investigations in Italy, Germany and Irelan d, polymerase chain reaction (PCR) amplification was used to detect he patitis A virus in frozen plasma pools, purified factor VIII, patient sera and samples from animal transmission studies; nucleic acid sequen cing was used to clarify and identify the virus responsible based upon genotype analysis. Unique virus strains were found among the cases in Italy and Germany, and identical virus sequences were also found in s ome factor VIII lots. However, with the exception of the Italian inves tigation, lack of appropriate samples have precluded the identificatio n of virus in these outbreaks. In addition, animal infectivity studies have not been successful in demonstrating infectivity under laborator y conditions. We discuss the limitations of PCR amplification with res pect to detecting virus within these situations, and the necessity for the corresponding epidemiologic investigations.