Booster hepatitis B vaccination not necessary for long-term protection in children immunised with hexavalent vaccines

Editoria

Is avian influenza virus A(H5N1) a real threat to human health?

The A(H5N1) influenza remains a disease of birds with a significant species barrier: in the presence of some tens million cases of infection in poultry - with a wide geographical spread -, only a few hundreds cases have occurred in humans. To date, human cases have been reported in 15 countries - mainly in Asia - and all were related to the onset of outbreaks in poultry. A peak of H5N1 human cases was recorded in 2006, then decreasing in subsequent years. Despite this trend, the H5N1 virus still represents a possible threat to human health, considering that more than half of human cases of H5N1 have been fatal. Moreover, despite the drop in the number of cases, the risk of a novel pandemic cannot be excluded, since H5N1 continues to circulate in poultry in countries with elevated human population density and where monitoring systems are not fully appropriate. In addition, there is a major global concern about the potential occurrence of a reassortment between the 2009 pandemic H1N1 and the highly pathogenic H5N1 influenza viruses following a co-infection in a susceptible host. Therefore, the implementation of appropriate surveillance and containment measures is crucial in order to minimize such risk. In conclusion, H5N1 avian influenza is still a rare disease in humans but its clinical severe outcome requires a careful monitoring of the virus?s ability to evolve and to trigger a new pandemic

Lessons learnt over two decades of vaccination against hepatitis B in Italy

This article reviews topics covered and discussed at the Meeting:  Vaccini e vaccinazioni. Migliorare lâoggi e preparare il domani, held in Genoa, Italy, on 12 September 2014. Data presented at the meeting, clearly showed that: 1) hepatitis B vaccination can confer long-term protection and there is no need for booster in immunocompetent vaccinees; 2) vaccination is highly effective in protecting population from clinical acute or chronic HBV infections, including hepatocellular carcinoma; 3) children vaccinated as infants with hexavalent vaccines maintain immunological memory 5 years after priming, but further studies are needed to assess whether immunity persists during the adolescence and adulthood when risk of exposure to HBV becomes higher; 4) the emergence of vaccine-escape mutants and Pol-gene mutants during antiviral therapy - which can result in changes in the S-gene - is of some concern, but at present there is no evidence that such mutants may pose a threat to the established programs of vaccination

Clinical, epidemiological and virological features of acute hepatitis B in Italy

Purpose To evaluate the association of hepatitis B virus (HBV) genotypes, basal core promoter (BCP)/precore (PC) and S gene mutations with the clinical-epidemiological characteristics of acute hepatitis B (AHB) in Italy. Methods During July 2005–January 2007, 103 symptomatic AHB patients were enrolled and prospectively followed up at 15 national hospitals. HBV genotypes, BCP/ PC and S gene variants were determined by nested-PCR and direct sequence analysis. Results Genotype D, A and F were detected in 49, 45 and 6 % of patients, respectively. BCP, PC, and BCP plus PC variants were found in 3.1, 11.3 and 7.2 % of patients, respectively. At enrollment, 68.3 % of patients were hepatitis B e antigen (HBeAg)-positive and 31.7 % HBeAg-negative. BCP/PC mutations were more common in HBeAg-negative than in HBeAg-positive patients (p < 0.0001). Compared to genotype D patients, those harboring non-D genotypes were more frequently males (p = 0.023), HBeAg-positive (p < 0.001), had higher bilirubin (p = 0.014) and viremia (p = 0.034) levels and less frequently carried BCP/PC mutations (p < 0.001). Non-D genotype patients more often were from Central Italy (p = 0.001) and reported risky sexual exposure (p = 0.021). Two patients had received vaccination before AHB: one harbored genotype F; the other showed a S gene mutation. Four patients developed fulminant AHB; mutations were found in 2 of 3 patients who underwent BCP/ PC sequencing. After a 6-month follow-up, only 2 (2.8 %) patients developed persistent infection. Conclusion AHB by non-D genotypes is increasing in Italy and is associated with risky sexual exposure. The ability of some genotypes to cause persistent and/or severe infection in Italy warrants larger studies for clarificatio

Molecular characterization and phylogenetic analysis of human influenza A viruses in three consecutive seasons with different epidemiological profiles

Introduction. Influenza activity and influenza virus circulation were observed in Lombardy (northern Italy) during three con- secutive seasons and the molecular characteristics of circulating viruses analysed to control for introduction of new variants. Methods. The molecular characterization of 38 isolates, namely 20 A/H3N2 and 18 A/H1N1 influenza strains from the 2005/06, 2006/07 and 2007/08 seasons, was performed by sequence analy- sis of the globular head region of the HA protein (HA1 subunit), specific for influenza virus A/H3 and A/H1. Results and discussion. The last three influenza seasons in the study region were characterized by medium-low activity. A typical co-circulation of several variants was shown for A/H3 viruses for approximately two years and were subsequently almost entirely substituted by new emerging variants. Vice versa, A/H1 viruses had a more homogeneous circulation with a single lineage clearly dominating each season. The HA sequences of the A/H3 and the A/H1 viruses isolated in the last three seasons fell into 4 and 3 principal phylogenetic groups, respectively. No evidence of positive or negative selection in the sequence align- ments was observed. Conclusions. Molecular characterization of the influenza viruses in three consecutive seasons highlighted considerable heteroge- neity in their HA sequences. A careful surveillance of genetic changes in the HA1 domain during seasonal influenza epidemics may reveal immune escape and provide early information on newly emerging strains with epidemiologic inference

Viable Newcastle Disease Vaccine Strains in a Pharmaceutical Dump

To assess the viability of discarded and buried vaccine strains, we examined vaccines that had been buried for >20 years in an industrial waste dump in the city of Milan, Italy. Viability results showed potential biological risk associated with uncontrolled burial of pharmaceutical industry waste, including some live vaccines

Early co-circulation of different clades of influenza A/H1N1v pandemic virus in Northern Italy

Introduction. The spatial diffusion over time of pandemic influenza A/H1N1 virus (A/H1N1v) was surveyed in Northern Italy (nearly 10 million inhabitants) from April to December 2009, and the molecular characteristics of circulating viruses were analyzed to identify the appearance of drift variants. About 45% of analyzed samples were laboratory-confirmed cases of A/H1N1v. Sporadic cases occurred until the middle of June 2009, then, case numbers began to increase delineating distinct epidemiological phases of viral circulation. Methods. RNA was extracted using RNeasy Mini kit (QIAGEN GmbH, Germany). Virological diagnosis of A/H1N1v infection was carried out by real-time RT-PCR assay. Sequence analysis of hemagglutinin (HA) gene was performed through a RT-PCR assay specific for a 995 bp fragment (nt. 64-1,058) in the HA1 domain. The nucleotide sequences were obtained by automated DNA sequencing. The HA1 sequences were aligned with other sequences collected from GenBank database by ClustalX software. The multiple sequence alignment was used to perform a basic phylogenetic analysis and a phylogenetic tree from HA sequences was constructed. Results. The HA gene sequences of A/H1N1v analyzed segregated into three genetically distinct clades and were characterized by the appearance of amino acid variations that were progressively fixed in the field viral population under scrutiny. Conclusions. These data suggest an early co-circulation of genetically distinct A/H1N1v variants and emphasize the importance of a close molecular surveillance to detect rapidly the spread of new viral variants and to define their epidemiological impact

The level of information on AIDS among the university and secondary school students of Camerino

A survey was carried out on students of Secondary School, "Obstetrics" and "Nurses", University, in order to evaluate their knowledge level about AIDS. Generally the inquired sample showed, in a satisfactory ratio, a good knowledge about AIDS topic; nevertheless, a certain confusion appeared about infection and illness meaning and the 23.0% of interviewed students believes that AIDS is not always lethal. Furthermore, blood-donation and insect bites are believed to be potential factors of transmission. Television was found as the most frequent source of information. From our data we suggest that a major role in educational sanitary programs should be played by a closer teacher-student relation