Key Role of Sequencing to Trace Hepatitis A Viruses Circulating in Italy During a Large Multi-Country European Foodborne Outbreak in 2013.

BACKGROUND: Foodborne Hepatitis A Virus (HAV) outbreaks are being recognized as an emerging public health problem in industrialized countries. In 2013 three foodborne HAV outbreaks occurred in Europe and one in USA. During the largest of the three European outbreaks, most cases occurred in Italy (>1,200 cases as of March 31, 2014). A national Task Force was established at the beginning of the outbreak by the Ministry of Health. Mixed frozen berries were early demonstrated to be the source of infection by the identity of viral sequences in patients and in food. In the present study the molecular characterization of HAV isolates from 355 Italian cases is reported. METHODS: Molecular characterization was carried out by PCR/sequencing (VP1/2A region), comparison with reference strains and phylogenetic analysis. RESULTS: A unique strain was responsible for most characterized cases (235/355, 66.1%). Molecular data had a key role in tracing this outbreak, allowing 110 out of the 235 outbreak cases (46.8%) to be recognized in absence of any other link. The data also showed background circulation of further unrelated strains, both autochthonous and travel related, whose sequence comparison highlighted minor outbreaks and small clusters, most of them unrecognized on the basis of epidemiological data. Phylogenetic analysis showed most isolates from travel related cases clustering with reference strains originating from the same geographical area of travel. CONCLUSIONS: In conclusion, the study documents, in a real outbreak context, the crucial role of molecular analysis in investigating an old but re-emerging pathogen. Improving the molecular knowledge of HAV strains, both autochthonous and circulating in countries from which potentially contaminated foods are imported, will become increasingly important to control outbreaks by supporting trace back activities, aiming to identify the geographical source(s) of contaminated food, as well as public health interventions.

Impact of nucleic acid testing for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus on the safety of blood supply in Italy: a 6-year survey.

BACKGROUND: Nucleic acid testing (NAT) for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) has been implemented in several European countries and in the United States, while hepatitis B virus (HBV) NAT is still being questioned by opinions both in favor and against such an option, depending on the HBV endemicity, health care resources, and expected benefits. STUDY DESIGN AND METHODS: This survey was aimed to assess the NAT impact in improving the safety of blood supply in Italy, 6 years after implementation. The study involved 93 Italian transfusion centers and was carried out in 2001 through 2006. A total of 10,776,288 units were tested for the presence of HCV RNA, 7,932,430 for HIV RNA, and 3,405,497 for HBV DNA, respectively. RESULTS: Twenty-seven donations or 2.5 per million tested were HCV RNA-positive/anti-HCV-negative; 14 or 1.8 per million units tested were HIV RNA-positive/anti-HIV-negative; and 197 or 57.8 per million donations tested were HBV DNA-positive/hepatitis B surface antigen-negative. Of the latter, 8 (2.3/10(6)) were collected from donors in the window phase of infection and 189 (55.5/10(6)) from donors with occult HBV. Sixty-eight percent of the latter donors had hepatitis B surface antibody, 74.5 percent of whom with concentrations considered protective (>or=10 mIU/mL). CONCLUSION: NAT implementation has improved blood safety by reducing the risk of entering 2.5 HCV and 1.8 HIV infectious units per million donations into the blood supply. The yield of NAT in detecting infectious blood before transfusion was higher for HBV than for HCV or HIV. However, the benefit of HBV NAT in terms of avoided HBV-related morbidity and mortality in blood recipients needs to be further evaluated.

Long-term outcome (35 years) of hepatitis C after acquisition of infection through mini transfusions of blood given at birth.

Long-term follow up studies of hepatitis C virus (HCV) infection rarely exceed 20-25 yr. We studied the outcome of HCV infection in 35-yr-old adults infected at birth (1968) through mini transfusions of blood. A retrospective-prospective study was carried out. The cohort included 31 individuals who were given mini blood transfusions (21-30 ml) collected from a donor subsequently revealed to be HCV infected. At enrollment (1998), 18 of 31 (58.1%) recipients had anti-HCV antibody and 16 (88.9%) of them were HCV-RNA positive. All viremic recipients and the infectious donor had the same genotype 1b. Sequence analysis of E1/E2 and NS5b regions, coupled with phylogenetic analysis, indicated that HCV isolates from donor/recipients were linked. Eleven of the 16 viremic recipients gave consent to liver biopsy. Nine had no fibrosis or mild portal fibrosis and 2 had either discrete (Ishak's staging 3) or marked (Ishak's staging 4) fibrosis. During the prospective follow-up period (1998-2003), 2 patients were given therapy, one of whom achieved sustained clinical and virologic response. A second biopsy, performed in 5 patients at a 5 yr interval, revealed no substantial modifications in 4 cases and progression from absence of fibrosis to mild portal fibrosis in the fifth. In conclusion, taking into account the limited study sample, these findings suggest that HCV infection acquired early in life shows a slow progression and mild outcome during the first 35 yr of infection.

Outcome of an outbreak of acute hepatitis C among healthy volunteers participating in pharmacokinetics studies.

We identified 15 patients with acute hepatitis C (AHC) among 29 healthy volunteers participating in 2 consecutive pharmacokinetics studies. Molecular techniques were used to determine the relatedness of viral strains, whereas clinical and virologic follow-up was started to establish the course and outcome of the acute infection. After presentation, serum liver enzymes and HCV RNA were monitored weekly for 4 months, then monthly for at least 12 months. Liver biopsy was performed 6 to 12 months after AHC diagnosis. Phylogenetic analysis of coding regions for the envelope glycoproteins E1 and E2 was performed. At presentation, all 15 patients tested HCV RNA-positive and had HCV genotype 2c. Phylogenetic analysis indicated a common source of infection. Fourteen patients agreed to be followed prospectively. Infection resolved spontaneously in 8 patients, HCV RNA becoming undetectable by 4 to 5 months after the presumed time of infection in 5 of them and by 8, 13, and 24 months in the remaining 3. Six patients developed chronic infection. Liver biopsies performed in 9 subjects who were HCV RNA-positive 6 months after AHC diagnosis revealed that the prevalent histologic finding was lobular inflammation. In conclusion, our homogeneous cohort showed a wide spectrum of clinical, virologic and histologic features, and, more importantly, short-term outcome differed noticeably despite the common source of infection.