Modelling and analysis of options for controlling persistent infectious diseases (11w5133)

Arriving in Banff, Alberta Sunday, February 27 and departing Friday March 4, 2011

Organizers

(McMaster University)

(McMaster University)

(University of Toronto)

Objectives

We have attended several successful BIRS meetings that have focused on the threat of emerging infectious diseases. These workshops have created links between mathematicians and statisticians, on the one hand, and researchers, public health practitioners and clinicians working in communicable disease control on the other. In the course of these meetings, it has become obvious that we share common interests in endemic infections -- diseases that are already here, causing illness and death, and whose biology we already understand reasonably well. We therefore feel it would be extremely valuable to gather the same sort of group, to discuss and share ideas about control of endemic infections.

We propose to structure the meeting around four major current challenges in the control of endemic infectious diseases. Each challenge will be the theme of a one day of the meeting, while the fifth day, will be reserved for roundtable discussions. Each day will begin with a lecture that introduces the theme and why it represents a major global public health challenge. Shorter talks will then follow, highlighting recent progress in addressing this challenge for specific diseases and/or the development of mathematical and statistical models and analyses that provide tools for making future progress in the area. We will strongly encourage presentations from graduate students and postdocs.

DAY 1: DISEASE-CONTROL PRIORITIES

* For influenza, who should public health officials target first for vaccinations? What is the best way to choose strains for the annual influenza vaccine? Why does influenza persist after pandemics, which immunize a large fraction of the host population?

* For malaria, how do current control and treatment methods affect pathogen evolution? What strategies are likely to be most effective at eliminating malaria from a given region?

* For HIV, what is the current shape of the epidemic curve in different regions of the world? What strategies are likely to be effective at getting and keeping the epidemic under control?

* For dengue, what is the current pattern of incidence in endemic areas? How do we expect this pattern to change as global climate changes? What strategies could minimize the impact of dengue if it spreads to larger regions?

* For West Nile Virus, what is the current annual pattern of incidence? What is the connection between host genetics and susceptibility to serious disease? How can the impact of WNV be minimized?

DAY 2: ENDGAME STRATEGIES

* Why have infectious diseases in general been so resistant to eradication?

* Can control and intervention strategies be crafted dynamically to increase the probability of disease fadeout?

* Why has the WHO failed to reach its target dates for eradication? What strategy is most likely to achieve eradication?

* For measles, how do the current vaccination strategies differ among the ~50 countries that still have endemic measles? What factors underlie measles resurgence in developed countries, including the UK?

DAY 3: ECONOMIC ISSUES IN RELATION TO DISEASE CONTROL

*How can we prioritize eradication strategies in a manner that takes into account local resources, capabilities, and priorities? For example, for control of malaria, what are the optimal combinations of emerging vaccines, vector control, and protective items such as bednets (or high quality housing stock) for local control of malaria? What are the signals or data inputs that tell us that a malaria control strategy needs modification for a given region, or that control strategies within a given region are failing and need revision?

*Indices of government corruption (e.g., Transparency International's Global Corruption Index) correlate well with local burden of mortality due to persistent infectious diseases. Can models provide insights into the interactions between complex systems (e.g., disease systems, systems of governance, and multinational aid organizations) that enhance the likelihood of successful disease control?

*Laxminarayan has shown that antimicrobial resistance is strongly analogous to the problem of depletion of a natural resource, and consequently amenable to representation using models derived from environmental economics. Similarly, game-theoretical approaches have given important insight into vaccination strategies. Many other persistent hurdles to disease eradication are amenable to investigation with ideas and tools from economics. How can economic approaches be used to understand and eliminate incentives for behaviour that goes against the public good, or long-term interests?

DAY 4: INTERACTIONS BETWEEN HUMAN BEHAVIOUR AND DISEASE SPREAD

*An important area of complexity in the representation and modeling of infectious diseases relates to the contribution of social connectedness (via family ties, sexual partnerships, travel, or commercial activity) to disease spread. Sexual network structures have been identified as a particularly important contributor to the ongoing endemnicity of theoretically eradicable diseases, such as syphilis, but these networks also provide a potential framework for innovative disease control strategies (e.g., via patient-delivered partner therapy for STDs). What is the current state of network models in the representation of disease transmission, and what is the potential for such models to provide insights into persistence of diseases that are projected to be eradicable using other modeling approaches?

*The association between infectious diseases and public panic has been documented since Thyucidides' account of the great plague of Athens. More recently, there is an emerging understanding that human beliefs and behaviours play a critical role, both positive and negative, in changing practices and contact patterns underlying disease spread. How can behavioral responses to infectious diseases be predicted, and possibly controlled in order to facilitate disease elimination?

The importance of developing and studying models of endemic infectious diseases would be hard to overstate. These diseases are responsible for millions of deaths annually, and their control and treatment is a major economic burden. By bringing together a group of mathematicians working on infectious disease modelling, public health researchers, and public employees engaged with the logistical realities of disease control, we will foster a productive interchange that will hopefully lead to substantial progress on the development of control strategies for important pathogens.

Finally, we hope to use this conference as a step towards better defining the study of persistence of infections as a field of endeavor within infectious disease epidemiology. In order to do so, the findings shared and goals developed at this meeting will have to be translated to the broader scientific, public health, and lay communities. We propose to do this in several ways: through subsequent presentation of summary slides by participants returned to their home institutions, through publication of 4 short review papers (each reflecting the theme discussed on one of the first four days of the conference) in peer-reviewed journals, and by posting conference documents to an interactive website.