Virology of the hepatitis A epidemic in Italy.

We studied the virologic aspects of a hepatitis A epidemic that occurred among hemophilia patients in Italy between 1989 and 1992. Twelve lots of factor VIII concentrate manufactured by the solvent-detergent chromatographic technique and suspected of contamination by the hepatitis A virus (HAV) were analyzed by a two-step, nested polymerase chain reaction (PCR) procedure. PCR was applied to 1-ml samples of factor VIII concentrate and 100-microliters serial serum samples available from 2 patients.

Transmission of hepatitis A to patients with hemophilia by factor VIII concentrates treated with organic solvent and detergent to inactivate viruses. The Italian Collaborative Group.

Objective: To determine whether an outbreak of hepatitis A virus (HAV) infection that occurred in 52 patients with hemophilia in Italy was acquired through infusion of contaminated factor VIII or through environmental enteric transmission.

Design: A case-control study and a molecular analysis of HAV sequences from implicated lots of factor VIII and from infected patients.

Patients: The first 29 patients with hemophilia and jaundice in whom hepatitis A developed were compared with one to three matched controls with hemophilia but no jaundice.

The CAEV tat gene trans-activates the viral LTR and is necessary for efficient viral replication.

Caprine arthritis-encephalitis virus (CAEV) is a lentivirus which is closely related by nucleotide sequence and biological properties to visna virus. Sequence analysis of the CAEV genome revealed the presence of a small open reading frame (ORF) which shares amino acid identity with the visna virus tat gene. Using an infectious molecular clone of CAEV the role of the tat ORF in viral replication was examined.

Molecular mechanisms of visna virus Tat: identification of the targets for transcriptional activation and evidence for a post-transcriptional effect.

Visna virus is a pathogenic lentivirus of sheep that is distantly related to the primate lentiviruses, including the human immunodeficiency virus type 1 (HIV-1). Replication of HIV-1 in cell culture requires the expression of a virus-encoded protein, Tat, which is a potent trans-activator of viral gene expression. Visna virus encodes an analogous Tat protein that greatly increases gene expression directed by the visna viral LTR.