Enteric viruses in molluscan shellfish.

One hundred and thirty-seven bivalves were collected for environmental monitoring and the market; all the samples were analysed by RT-PCR test. Bacteriological counts meeting the European Union shellfish criteria were reached by 69.5% of all the samples, whereas the overall positive values for enteric virus presence were: 25.5%, 18.2%, 8.0% and 2.1% for Rotavirus, Astrovirus, Enteroviruses, Norovirus, respectively. Mussels appear to be the most contaminated bivalves, with 64.8% of positive samples, 55.7% and 22.7% respectively for clams and oysters, whereas in the bivalves collected for human consumption 50.7% were enteric virus positive, as compared to 56.4% of the samples collected for growing-area classification. The overall positive sample was 54.0%.

Identification and sequence analysis of hepatitis A virus detected in market and environmental bivalve molluscs.

In Italy in 1998, hepatitis A virus (HAV) was responsible for an infectious disease transmitted by contaminated bivalve molluscs. To determine the presence of HAV in the bivalves collected during a 1-year follow-up study, hepatitis A RNA was extracted and amplified by a nested reverse transcriptase-PCR method overlapping the VP1/2A region. The HAV genome was detected in 24 (14.1%) of 170 samples: 19 clams (Tapes decussates and Tapes semidecussatus), 1 oyster (Crossostea gigas), and 4 mussels (Mytillus galloprovincialis). Eleven positive samples were collected from marketing areas, and 13 positive samples were collected from growing areas. Seventeen of the 24 positive samples had been taken from domestic products, and 7 had been imported. Sequence analysis showed the presence of genotypes IA and IB. Our results suggest significant presence of HAV in bivalves from both marketing (public consumption) and environmental (growing) areas.

Nucleotide correlation between HAV isolates from human patients and environmental samples.

Hepatitis A disease is endemic in Albania even though records from the Medical Authority show outbreaks involving only limited numbers of people. In the city of Lac, 200 people became ill following an outbreak of hepatitis A started on November 2002. The age distribution of the cases shows a peak in the age group 5-9 (43.5%) followed by the age group 10-14 (28%) and the age group 1-4 (18%). No cases were recorded in the age group 0-1. Drinking water and sewage samples were collected, using electropositive cartridges, during the outbreak. Rotavirus was identified by RT-PCR in two out of five drinking water samples; however, all the samples tested negative for HAV and astrovirus. Rotavirus was also identified in three out of five sewage samples from which four were HAV positive. HAV-RNA was identified in 28 (62.2%) out of 45 IgM anti-HAV positive sera collected during the outbreak. Genotype IA was expressed from all the amplified samples. Sequence analysis of the overlapping VP1-2A region shows 97-99% homology with three Italian strains IT-SCH-00, IT-ZAM-01, and IT-CAP-00 and one Spanish strain (Sa 30/06/95), whereas the phylogenetic tree built from the 168 bp sequence of the VP1-2A shows four clusters, one including 24 out of 28 RT-PCR positive sera. Considering the deduced amino acid sequence, only one substitution was identified and reported previously for genotype IB.

Hepatitis in Albanian children: molecular analysis of hepatitis A virus isolates.

Hepatitis A is a common disease in developing countries and Albania has a high prevalence of this disease associated to young age. In spite of the occurrence of a unique serotype there are different genotypes classified from I to VII. Genotype characterisation of HAV isolates circulating in Albania has been undertaken, as well as the study of the occurrence of antigenic variants in the proteins VP3 and VP1. To evaluate the genetic variability of the Albanian hepatitis A virus (HAV) isolates, samples were collected from 12 different cities, and the VP1/2A junction amplified and sequenced. These sequences were aligned and a phylogenetic analysis performed. Additionally, the amino half sequence of the protein VP3 and the complete sequence of the VP1 was determined. Anti-HAV IgM were present in 66.2% of all the sera. Fifty HAV isolates were amplified and the analysis revealed that all the isolates were sub-genotype IA with only limited mutations. When the deduced amino acid sequences were obtained, the alignment showed only two amino acids substitutions at positions 22 and 34 of the 2A protein. A higher genomic stability of the VP1/2A region, in contrast with what occurs in other parts of the world could be observed, indicating high endemicity of HAV in Albania. In addition, two potential antigenic variants were detected. The first at position 46 of VP3 in seven isolates and the second at position 23 of VP1 in six isolates.