This proposal is part of the overall GGD/AMC collaborative for public health. Reviewers are kindly requested to read the general description of this collaborative first (Annex 1 to 3). This proposal describes how through a research network on infectious diseases established in this GGD/AMC collaborative existing problems related to policy and practice in public health in Amsterdam will be addressed and will contribute to more evidence-based service practices in prevention and control programmes for infectious diseases. The infectious diseases network of the GGD/AMC collaborative will be embedded in the framework of the Center for Infection and Immunity Amsterdam (CINIMA) of the AMC, of which the Amsterdam GGD cluster Infectious Diseases is an affiliated external institute. Since the early 1980s the cluster Infectious Diseases has played an important role in the prevention and control of infectious diseases in the Netherlands. Moreover, epidemiological studies and the evaluation of interventions (e.g. vaccines and prevention programmes) have become major activities of the cluster which now serves as an expertise centre for public health research in this field. The character of our research has always been multi-disciplinary and we have a long record of working together with the AMC. However a major weakness is that the collaboration never has been formalised. It was based on incidental funding and depended for an important part on the former general director of the GGD. The call for the setting-up of an academic collaborative centre for public health offers us the unique opportunity to establish a structural collaboration with the AMC in the public health sector of infectious diseases. With the AMC/GGD network for infectious diseases we will reinforce our multidisciplinary research so that all that has been built up in the past will not get lost in the future. The network will enhance knowledge transfer between the GGD (research on infectious diseases epidemiology and prevention practices) and the AMC (clinical research and community based integrated care). As part of the general cooperation within the network, which comprises various structural arrangements (unified leadership, double appointments of senior-and junior staff, education, regular meetings), three specific PhD research projects will be executed. The network will also facilitate new grant proposals. The three research projects proposed here involve the fields of (1) sexually transmitted infections (STI), (2) hepatitis C virus (HCV) and (3) travellers infections. In short the proposed research on STI will help to understand the re-emergence of STI among heterosexual individuals and contribute to better prevention by working closely with national prevention organisations. More specific, in anticipation of vaccines for HSV2 and HPV, the proposal will contribute to essential questions such as on which age to vaccinate, whether targeted or universal vaccination should be applied, and what the composition of the vaccine should be. The proposed STI project will also contribute to the question whether it will be effective to routinely screen HIV-infected individuals for STI and to integrate STI screening in HIV care settings in the Netherlands. The research on HCV will reveal insight into the spread and impact of HCV infections and its future burden. This information is lacking in the Netherlands, but urgently needed to direct the HCV testing policy and to target effective prevention measures. This information is also important for the development of the first national information campaign for HCV. In addition, the HCV research includes the evaluation of a protocol that integrates HCV care and treatment with existing methadone programmes, potentially a model for the treatment of all chronically HCV-infected drug users, the largest group with HCV in the Netherlands. Implementation of the final protocol will decrease the costs related to the fatal consequences of HCV, and increase the quality of life and life expectancy of HCV-infected persons. Finally, the research on travellers infections will result in a better insight in the epidemiology of travel-related infections and will improve travellers health advices for young and old, healthy and unhealthy travellers. Results from these studies will be implemented in national guidelines for travel health advice.