The American Academy of Microbiology convened a colloquium with a diverse group of scientists to discuss how climate influences health and infectious diseases. The colloquium, held on October 15-17, 1999 in Tucson, Arizona, was a follow-up to a 1997 colloquium, "Climate, Infectious Disease, and Health: An Interdisciplinary Perspective." The report of the 1997 colloquium served as one of the first reviews to highlight this emerging field of study. In addition, key areas of research, collaboration, and data needs were identified. The second colloquium, upon which this report is based, convened to assess the current "state of the field"—or where we have come and where we are going. In the last three years, scientists in the fields of climatology, meteorology, microbiology, medicine, ecology, epidemiology, oceanography, and space science have collaborated to study how natural climate variability affects occurrence and prevalence of pathogenic microorganisms, vectors, and disease outcomes.
The unusually strong El Niño event of 1997-1998, followed by two years of strong La Niña conditions, the worst hurricane season on record, and further debate over anthropogenically induced climate change, have all been heavily covered by the popular press worldwide. Such widespread coverage demonstrates that the potential human-scale impacts of climate variability and climate change are of interest to the public. Partly in response to growing public concern, the United States Congress, in 1997, commissioned the United States Global Change Research Group (USGCRP) to develop a National Assessment of the Effects of Climate Change. However, the connection between oceans, climate and public health has been a subject of scientific discussion for the past decade. The science has progressed largely through joint efforts put forward by investigators from different disciplines.
The ability to understand and model the complex links between environmental, climatological, and biological systems present great opportunities for prediction and prevention of disease, rather than the current approach that heavily depends on clinical cases to appear before action is taken. The ability to predict potential outbreaks, based on susceptible populations and climate variability, is especially important for certain regions in developing nations where limited resources may be more efficiently utilized in advance to prevent a health crisis. Our goal in understanding and incorporating climate signals, therefore, is to use proactive, rather than reactive, approaches to protect public health.
Scientists are continuing to connect ocean sciences with human health. By defining and understanding such interactions there are hopes to develop models that will aid in the prevention of emerging and re-emerging diseases. To advance our understanding of the relationships between climate variability and infectious diseases, the following recommendations are made. Long term, historical disease and pathogen surveillance data must be located, salvaged, and electronically archived. Continuing emphasis should be placed on prospective long-term surveillance that includes medical, ecological, and climatological parameters at periods greater than five years. Multidisciplinary training in "bioclimatology" should be encouraged at all levels—undergraduate through postdoctoral. Increased communication between disciplines is imperative, but will require a common "language," as well as support for interdisciplinary meetings and journals that focus on climate issues in biological and medical applications. Scientific societies may be best able to accomplish this goal. Quantitative analyses should move from the detection of associations to the development of predictive models. Finally, integrated frameworks and risk assessments will be useful tools to determine susceptibility of particular regions to certain diseases under a given set of climate conditions.
Climate variability affects every region of the world. Diseases are not necessarily limited to specific regions, and a changing climate may allow pathogens or vectors to become endemic in novel regions. Therefore, although the impact of climate on health may be local in an immediate sense, it is nevertheless a global issue.