THE ROLE OF VENTILATION IN THE SPREAD OF MEASLES IN AN ELEMENTARY SCHOOL

I am delighted to participate in this conference on airborne contagion and compare notes on dissemination mechanisms. In the early 1930s, before I studied medicine, I worked with Professor William F. Wells at Harvard. First we studied airborne organisms around the Cambridge sewage treatment plant and later the effect of contaminated humidifying water on airborne organisms in textile mills in Massachusetts. After we left Boston, our paths separated; I went to medical school in New York City and Professor Wells moved his laboratory to Philadelphia, Pennsylvania, and later to Baltimore, Maryland. Not until I retired in 1970 did I return to the study of airborne contagion; but in Baltimore, my brother, Doctor Richard Riley, and Professor Wells collaborated for many years prior to Wells’ death in 1963 in the Baltimore Veterans Administration Hospital. For several years while in Philadelphia, Professor Wells and his wife, Mildred Wells, M.D., studied epidemics of contagious diseases in primary and secondary schools. These studies were designed to demonstrate the potential of ultraviolet irradiation of the upper portion of classrooms for the control of airborne disease. The irradiation changed the rate and pattern of spread, but the results were inconsistent and there was no satisfactory explanation for the failure of some installations to prevent airborne spread of disease. Although not directly involved in these studies, I shared Wells’ conviction that many contagious diseases were airborne and that sterilization of the ambient air should prevent airborne infections. For many years, either the Soper equation or the Reed-Frost modification has provided the conceptual model for the spread of contagious disease.