Epidemiologists: Aerial Photography and Other Remote Sensing Techniques” (Cline, 1970) in the American Journal of Epidemiology little could I imagine that 20 years later the first International Conference on Applications of Remote Sensing to Epidemiology and Parasitology would be held (Louisiana State University, Baton Rouge, June 67, 1990), nor that Geospatial Health would make its debut in 2006. When I wrote this paper, my first, I was a doctoral student in epidemiology at the University of California, Berkeley. The great arbovirologist/epidemiologist William C. Reeves was my faculty mentor, overseeing my research on the distribution in humans of neutralizing antibodies to vesicular stomatitis virus in Central America and Panama (Cline, 1973, 1976). Over 50% of the human population had serologic evidence of past infection, yet the means of transmission was unknown. Among possible determinants of transmission I wanted to classify the ecological characteristics of the hundreds of study communities, but these data were only available in very crude form. Hoping that aerial photographs of the communities would offer a more precise means of ecological classification, I enrolled in the course “Aerial Photo Interpretation” offered by the University of California’s Department of Geography and taught by Robert N. Colwell, a leading authority on remote sensing of natural resources. I recall my fascination in learning from Professor Colwell about the wide range of remarkable applications of remote sensing in agriculture, forestry, hydrology, oceanography, range and wildlife management, geography and cartography. A dramatic example, I learned that early disease and stress in trees and other crops could be detected remotely before evidence was apparent from ground level inspection! From my epidemiology studies I was beginning to appreciate that while most pathogens transmitted in a human-to-human cycle are not constrained geographically, zoonotic and insect-transmitted diseases, in contrast, tend to be focal in distribution, with their maintenance cycles dependent upon exacting ecological conditions. The term “landscape epidemiology”, coined by the Soviet Academician E.N. Pavlovsky (1884-1965), provided the spark which led me to link remote sensing with epidemiology, and to begin speculating about how epidemiology might be added to the list of disciplines for which remote sensing provided a powerful tool for investigation and disease control. Pavlovsky and his colleagues developed the concept of “disease nidality”, i.e. that certain diseases such as old world leishmaniasis and tick-borne encephalidities, occupy ecological niches much in the same manner as any living thing has a characteristic niche in nature (Pavlovsky, 1966). Russian Spring and Summer Encephalitis (RSSE), associated with the taiga forests of Siberia, is another example. This concept was expanded by Western investigators such as Ralph Audy at the University of California, San Francisco, who applied it to the Corresponding author: Barnett L. Cline Professor Emeritus, Tulane University Current address: P.O. Box 1477 Blanco, Texas 78606, USA E-mail: blchome@moment.net Invited editorial for the inaugural issue of Geospatial Health