Global Monitoring of Emerging Infectious Diseases: Predicting Outbreaks by Monitoring

Infectious diseases remain major causes of disease and death worldwide.  Although many are ancient, new infections are increasingly entering the human population, or rapidly spreading from a geographically limited area.  These “emerging infections” (infections that appear suddenly, or are rapidly increasing in number of cases or geographic range) include HIV/AIDS, SARS (Severe Acute Respiratory Syndrome), Nipah, and pandemic influenza.  Emerging infections often already exist in other species or in geographically limited human populations but get an opportunity to come in contact with new human populations, or to spread, often as the result of changes in ecology and land use, or such factors as increasing urbanization and globalization.  Therefore, it is essential to have early warning and monitoring – surveillance – if we wish to prevent existing infectious diseases from increasing their range, or to prevent the next pandemic.  As many emerging infections, or their close relatives, already exist in other species, the “One Health” approach is invaluable in helping to identify and track these pathogens in nature, and to target surveillance efforts.  The “One Health” approach allows integrating surveillance activities across species to allow data to be placed in context and permit early warning of important changes in characteristics such as host range or geographic distribution.  However, we urgently need and do not have adequate capabilities in place for global surveillance of infectious diseases, including new emerging infections. In the mid-1990’s, ProMED (the international Program for Monitoring Emerging Diseases, now part of the International Society for Infectious Diseases), and its e-mail listserv ProMED-mail (currently with >40,000 subscribers in at least 185 countries), were initiated to plan and promote such global surveillance.  In another major development, in 2009 the U.S. Agency for International Development (USAID) began the “Emerging Pandemic Threats” (EPT) program, which includes PREDICT, a project to build global capacity for surveillance and prediction of novel infections that have pandemic potential.  EPT/PREDICT uses the “One Health” approach to target and integrate surveillance in wildlife, livestock, and humans, and develop a framework for risk assessment.  These approaches are enabled by improved understanding of factors driving infectious disease emergence, and new technological capabilities for modeling and informatics, diagnostics and pathogen identification, and communications (e.g., disease reporting using cellphones).