REINFECTIONTHRESHOLD · Reinfection thresholds and the management of recurrent infections
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-04-01 → 2009-03-31
- EU contribution
- €1,884,679
- Participants
- 1
- Scheme
- EXT
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Results in brief
Final Activity Report Summary - REINFECTIONTHRESHOLD (Reinfection thresholds and the management of recurrent infections)
The project develops a conceptual framework to study the global epidemiology of infectious diseases. The reinfection threshold concept, introduced by the team leader to indicate the transmission potential required for disease persistence in a population of partially immune individuals, underlies a phenomenological transition in epidemic dynamics whose manifestations depend on disease specificities. We challenged conclusions obtained with previous models and formulate new explanations for field observations. Our research combines two transversal axes: 1. To increase the accuracy and practical value of the reinfection threshold by focusing on specific infections; 2. To perform comparative studies across different infections, extract general trends, and standardise concepts for use in public health practice. We establish a pivotal role for the reinfection threshold in a range of infectious diseases. In tuberculosis, we note that communities that sustain transmission intensities above threshold are generally insensitive to vaccination. In pertussis, we attribute the recent resurgence of the disease in developed countries to a decrease in transmission. In malaria, we identify a threshold for elimination in regions of low to moderate transmission intensity. In diseases caused by antigenically diverse pathogens, such as influenza and dengue, a reinfection threshold has a destabilizing effect that favours polymorphism. More generally, we develop conceptual models for the ecology and evolution of infectious diseases and construct quantitative models of pathogen transmission, diversification and selection, which may be further developed as tools in the design of medical interventions. Finally, we propose laboratory experiments to test specific ideas from theoretical epidemiology. The team has been engaged in fostering and implementing public databases and interdisciplinary research in epidemiology, and raising public awareness for the diversity of scientific research associated with infectious diseases.
Data: CORDIS, © European Union
Project objective
Infectious disease is the leading cause of morbidity and mortality in developing countries, and one of the leading causes worldwide. The twentieth century witnessed spectacular decays in infectious disease. Vaccines have eliminated smallpox, and have dramatically reduced the incidence of childhood diseases. A major concern is that the success of vaccination and other control measures is far from uniform. Interventions aimed at reducing tuberculosis, malaria, and several respiratory and diarrhoeal diseases have generally failed.The management of recurrent infections is a major global challenge for biomedical science and public health in the twenty-first century. Recurrent infections occur as pathogens evolve a variety of ways to circumvent immunity: persisting at reduced activity (Mycobacterium tuberculosis, Plasmodium spp), or confusing the immune system by change in appearance (influenza virus, respiratory syncytial virus). Empirical relationships between such elaborate host-pathogen interactions and the observed epidemiological patterns are difficult to deduce.Simple mathematical models are useful conceptual tools, but the potential for unwanted artefacts increases dramatically as each layer of complexity is introduced. These will be paralleled by more flexible computer models, combining the dynamics of infection, immunity, and pathogen ecology. Intervention design will be explored in the presence of reinfection, space, stochasticity, and resonance effects.Many high impact diseases (tuberculosis, malaria and respiratory diseases) are considered in depth, and the results given a broad perspective. Theoretical models will be developed in coordination with laboratory and fieldwork, with two complementary roles: (1) assess the epidemiological impact of mechanisms of infection and immunity; (2) set targets for future interventions. The control of complex infectious disease problems is currently a major challenge where integrated approaches are in great demand.
Original text from CORDIS.
Participants
- FUNDAÇÃO CALOUSTE GULBENKIAN · LISBOACoordinatorPortugal
Links
Data: CORDIS, © European Union