Epidemiology Crucial to Cracking Elizabethkingia Crisis

Abstract

Editorial In 1854, a cholera epidemic struck London, England. John Snow, a local physician and researcher, was focused on determining the source of the illness. He dismissed the popular thought of the time that infectious diseases were caused by “miasmas,” the inhaled contaminated vapors or gases that were thought to arise from sewers, garbage dumps and other less appealing areas. Snow’s investigations led to a theory that the source of infection was actually germs in the public water ingested by patients, thus causing the digestive symptoms of the disease. He tested this theory by speaking with the inhabitants of neighborhoods in which cholera hit, mapping the cases of disease and linking the cases to water pumps that supplied the public water to these neighborhoods. 1 This innovative scientific approach came to be called the epidemiologic triangle (Figure 1). 2 The three corners of the triangle represent the agent, the environment and the host. The agent is the microbe that causes the disease. The environment is made up of the external factors that cause or allow disease transmission. The host is the person or organism that harbors the disease. In Snow’s cholera investigation, the agent was the bacteria Vibrio cholera, the environment was the contaminated water from public water pumps, and the host was one who drank the contaminated water.