enzooticity

Enzooticity is a term in veterinary epidemiology describing the state or condition of a disease being enzootic in animal populations within a particular geographic area. When a disease is enzootic, it is regularly found among the animal hosts and is maintained in the population over time through ongoing transmission, often with a relatively stable baseline level of infection. The concept is commonly applied to livestock, wildlife, and, less often, companion animals.

It is contrasted with epizootic disease, which refers to a sudden, widespread outbreak that exceeds the normal level of disease activity. Enzooticity is closely related to the idea of endemicity; however, endemicity can apply broadly to humans or animals, while enzooticity specifically emphasizes the animal domain. In public health, enzooticity can indicate persistent reservoirs or transmission cycles that may pose a risk of spillover to humans or other species.

Assessment of enzooticity relies on surveillance data, including prevalence or seroprevalence studies, incidence over multiple years, and patterns of transmission. It is an important concept for wildlife management and veterinary medicine, guiding control strategies, vaccination programs, and monitoring of potential zoonotic threats.

Examples of diseases described as enzootic in certain regions include enzootic bovine leukosis in cattle, enzootic pneumonia in pigs, and various enzootic respiratory or hemorrhagic diseases in wildlife. The term is used less frequently in contemporary practice, with emphasis often on specific disease names and the notion of endemicity; nonetheless, enzooticity remains a useful descriptor of persistent disease in animal populations.