Suchergebnisse

During the last decade, the chikungunya (CHIKV) virus has expanded its range of activity, conquering new territories and becoming an important global health threat. In particular, the challenge represented by the recent emergence of CHIKV in the Americas has strengthened the need of a safe and effective vaccine. Although research on vaccines against CHIKV has been slow, a few vaccine candidates have been tested over the years. Inactivated and attenuated vaccine candidates have shown promising results in phase I/II trials, and engineered vaccines have proven to be safe and immunogenic in mouse and/or non-human primate models. Recently, a vaccine based on virus-like particles (VLP) has been successfully tested in a phase I trial. However, large phase I/II controlled trials, which are needed in order to provide evidence of vaccine efficacy, may be planned only under certain conditions. First, they should be conducted during epidemic periods, when a large number of cases occur, in order to ensure an adequate study power. Second, they are expensive and investments returns are not always guaranteed. To overcome this problem, public/private partnership and government support, the identification of target population groups for vaccination and the commitment of donor agencies are key factors for supporting both the development and the availability of vaccines against neglected tropical diseases like chikungunya.

Contents -- Preface - Emerging Viruses: From Early Detection to Intervention -- References -- How to Tackle Natural Focal Infections: From Risk Assessment to Vaccination Strategies -- 1 Eco-Epidemiology: How to Predict and Control the Occurrence of Natural Focal Infectious Diseases -- 1.1 Ecological Niche Modelling -- 1.2 The Boosted Regression Trees Method -- 1.3 Macroecology -- 2 Natural Focal Diseases Mapping and Control: Two Paradigmatic Examples -- 2.1 Crimean-Congo Hemorrhagic Fever: A Mapping Exercise -- 2.2 A Vaccine for CCHF: Give Prevention a Chance -- 2.3 Tick Borne Encephalitis: Vaccine Use to Control a Natural Focal Disease -- 3 Conclusions -- References -- Human-Animal Interface: The Case for Influenza Interspecies Transmission -- 1 Introduction -- 2 The Viruses -- 3 Molecular Determinants of Host-Range Restriction and Pathogenesis -- 3.1 Hemagglutinin and Receptor-Binding Specificity -- 3.2 Other Virulence Determinants -- 4 Pandemic Influenza -- 5 Animal Influenza -- 5.1 Wild Bird-Domestic Bird Interface -- 5.2 Domestic Bird-Mammalian Interface -- 5.2.1 Domestic Poultry -- 5.2.2 Swine Influenza -- 6 Increasing Threats of Influenza at the Human-Animal Interface -- Changing Conditions that Favor Influenza Transmissibility -- 7 Conclusions -- References -- Bats and Emerging Infections: An Ecological and Virological Puzzle -- 1 Introduction -- 2 Why the Bats Are Good Virus Reservoirs? -- 2.1 Evolution and Phylogeny of Bats -- 2.2 Species Richness -- 2.3 Ability to Fly -- 2.4 Long Lifespan and Bat Ecology -- 3 Virus Dynamic in Bat Populations -- 4 Changes in Ecology and Management of Bat Populations -- 5 Risk Factors and Prevention Tasks -- References -- The Middle East Respiratory Syndrome Coronavirus - A Continuing Risk to Global Health Security -- 1 Introduction -- 2 Epidemiological Features of MERS-CoV -- 2.1 Discovery and Evolution

The global eradication of polio is close to achieving success. However, transmission of wild poliovirus persists in countries where the disease is endemic, and outbreaks may also occur in previously polio-free countries where population immunity is not maintained. To achieve polio eradication, several key actions are required: (1) to detect any poliovirus transmission, (2) to strengthen immunization systems and withdraw all oral polio vaccines from use, (3) to contain polioviruses and certify interruption of transmission, and (4) to sustain ongoing public health programs. In this context, residual hurdles to global polio eradication have been identified, from unstable political situation in affected countries to population movements from and to endemic areas, and opposition to immunization strategies. Global efforts are needed in order to promote routine immunization campaigns and large-scale vaccination rounds, which may provide direct protection of individuals and minimize virus circulation.

Italy introduced a national law extending the number of compulsory vaccines from four to 10 in July 2017. The implementation placed a further burden on immunisation centres as they were required to cover the increased demand of vaccination by the parents of unvaccinated children. Vaccine coverage (VC) estimated 6 months and 1 year later, at 24 and 30 months (same birth cohort), had increased for all vaccines. At 24 months of age, measles VC increased from 87.3% in 2016 to 91.8% in 2017 and 94.1% at 30 months of age as at June 2018. In six of 21 regions and autonomous provinces, VC for measles was >95%. Despite the implementation of this law, vaccine hesitancy is still a problem in Italy and the political and social debate on mandatory vaccination is ongoing. Regardless of the policy to be adopted in the future, strategies to maintain high vaccination rates and the related herd immunity should be considered, including adequate communication to the population and the implementation of electronic immunisation registries.

We conducted a study to describe current patterns of drug-related behaviors, and to identify characteristics that may distinguish injecting drug users entering treatment from those out of treatment, in five Italian cities. Overall, 1,180 subjects were recruited — 568 entering treatment and 612 out of treatment. Male to female ratio was 6.6:1. The median age was similar in the two groups. A high proportion of injecting drug users recruited out of treatment had been in treatment at least once. HIV prevalence among injecting drug users entering treatment was not higher than that of those who were out of treatment. Furthermore, a large proportion of injecting drug users who still were out of treatment reported having adopted safe behaviors. The results of the study emphasize the need to implement outreach programs aimed at harm reduction.

After the national lockdown imposed on March 11, 2020, the Italian government has gradually resumed the suspended economic and social activities since May 4, while maintaining the closure of schools until September 14. We use a model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission to estimate the health impact of different exit strategies. The strategy adopted in Italy kept the reproduction number R(t) at values close to one until the end of September, with marginal regional differences. Based on the estimated postlockdown transmissibility, reopening of workplaces in selected industrial activities might have had a minor impact on the transmissibility. Reopening educational levels in May up to secondary schools might have influenced SARS-CoV-2 transmissibility only marginally; however, including high schools might have resulted in a marked increase of the disease burden. Earlier reopening would have resulted in disproportionately higher hospitalization incidence. Given community contacts in September, we project a large second wave associated with school reopening in the fall.