Emerging zoonotic diseases: An opportunity to apply the concepts of nidality and one-medicine

The use of animals as sentinels of human disease revolves around the concept of nidality. That is, an agent of disease occupies a particular ecologic niche and alterations in that niche will change the function of that agent relative to traditional host-agent-environment relationships. Nidality is a derivation of the root word nidus. Nidus is defined as a nest or breeding place, particularly a place where microbes such as bacteria, fungi, viruses, as well as other organisms and larger parasites, are located and multiply. Application of the concept of nidality and development of prevention strategies has most frequently been associated with military campaigns and interruption of tick-borne infections. Modern usage of the phrase “one-medicine” was popularized in the United States and Europe by Calvin Schwabe and the concept is attributed to Rudolph Virchow. It is applied today to the study of zoonotic disease and interventions in rural agricultural communities that share close living arrangements between people and their families, their pastoral work environment, and the animals for which they care. Integration of the two concepts of one-medicine and nidality provides an opportunity to apply a systems approach (i.e. general systems theory) to dealing with emerging zoonotic diseases in today’s global agricultural and industrial settings.