Eradication

Eradication is the permanent reduction to zero of the worldwide incidence of a disease or other health problem, achieved through deliberate, coordinated interventions. Once eradicated, no further interventions are required to prevent transmission. This is distinct from elimination, which achieves zero incidence in a defined area but allows for reintroduction, and from control, which reduces disease burden without stopping transmission entirely. Eradication campaigns also occur in pest and invasive-species management, where the target population is permanently removed from a region.

Historically, smallpox is the most notable human disease eradication, with global transmission interrupted and declared eradicated in 1980 after vaccination and surveillance. Rinderpest, a livestock disease, was certified eradicated in 2011. Other efforts, such as poliovirus eradication and Guinea worm disease eradication, have made substantial progress but have not yet achieved global eradication; poliovirus remains endemic in a small number of areas and reintroduction remains a risk. Eradication programs depend on sustained surveillance, accurate diagnostics, and durable tools, as well as political will and secure funding.

Prerequisites for eradication include the absence of a non-human reservoir, an effective intervention, capable diagnostics, and the ability to monitor transmission continuously. Practical challenges include logistical complexity, cost, potential ecological or social impacts, and the risk of reemergence after a period of zero reported cases. Because eradication requires global interruption of transmission, it remains a rare and ambitious outcome, pursued selectively where the conditions for success are judged favorable.