Observation, Medical

Observation, Medical 

(in Russian, observatsia), a procedure for checking persons who have emigrated from or lived in populated regions or countries that are infected with plague, smallpox, cholera, or yellow fever. Observation is part of the way in which a nation protects its borders from incoming disease. The duration of the observation period depends on the incubation period of the disease. The incubation period is determined from the last moment of contact with a victim of the disease or from the most recent moment of departure from a geographical focus of infection.