Modeling infectious disease dynamics in the complex landscape of global health.

Despite some notable successes in the control of infectious diseases, transmissible pathogens still pose an enormous threat to human and animal health. The ecological and evolutionary dynamics of infections play out on a wide range of interconnected temporal, organizational, and spatial scales, which span hours to months, cells to ecosystems, and local to global spread. Moreover, some pathogens are directly transmitted between individuals of a single species, whereas others circulate among multiple hosts, need arthropod vectors, or can survive in environmental reservoirs. Many factors, including increasing antimicrobial resistance, increased human connectivity and changeable human behavior, elevate prevention and control from matters of national policy to international challenge. In the face of this complexity, mathematical models offer valuable tools for synthesizing information to understand epidemiological patterns, and for developing quantitative evidence for decision-making in global health.

Detection and treatment of subclinical tuberculosis.

Reduction of active disease by preventive therapy has the potential to make an important contribution towards the goal of tuberculosis (TB) elimination. This report summarises discussions amongst a Working Group convened to consider areas of research that will be important in optimising the design and delivery of preventative therapies. The Working Group met in Cape Town on 26th February 2012, following presentation of results from the GC11 Grand Challenges in Global Health project to discover drugs for latent TB.

Planning to improve global health: the next decade of tuberculosis control.

The Global Plan to Stop TB 2006-2015 is a road map for policy-makers and managers of national programmes. It sets out the key actions needed to achieve the targets of the Millennium Development Goals relating to tuberculosis (TB): to halve the prevalence and deaths by 2015 relative to 1990 levels and to save 14 million lives. Developed by a broad coalition of partners, the plan presents a model approach combining interventions that can feasibly be supplied on the ground. The main areas of activity set out in the plan are: scaling up interventions to control tuberculosis; promoting the research and development of improved diagnostics, drugs and vaccines; and engaging in related activities for advocacy, communications and social mobilization. Scenarios for the planning process were developed; these looked at issues both globally and in seven epidemiological regions. The scenarios made ambitious but realistic assumptions about the pace of scale-up and implementation coverage of the activities. A mathematical model was used to estimate the impact of scaling up current interventions based on data from studies of tuberculosis biology and from experience with tuberculosis control in diverse settings. The estimated costs of the activities set out in the Global Plan were based on implementing interventions and researching and developing drugs, diagnostics and vaccines; these costs were US$ 56 billion over 10 years. When translated into cost per disability adjusted life year averted, these costs compare favourably with those of other public health interventions. This approach to planning for global tuberculosis control is a valuable example of developing plans to improve global health that has relevance for other health issues.