LANDSCAPE CHARACTERISTICS OF THE DISTRIBUTION AREA OF OMSK HEMORRHAGIC FEVER,
NAVAL MEDICAL RESEARCH UNIT NO 3 CAIRO (EGYPT) DEPT OF MEDICAL ZOOLOGY
Pagination or Media Count:
The boundaries of distribution areas of different natural focal diseases are determined by external environmental factors that allow the agent to exist in natural conditions for a long period. The epidemiological development of such diseases depends on the probability of human contact with a natural focus as well as on features of the natural state of the focus. This may be continuous, manifested annually in different rates as tickborne encephalitis or periodic discontinuous, lasting for many years with intervals of favorable epidemiological conditions plague, tularemia, Omsk hemorrhagic fever, etc.. The appearance of epidemiological outbreaks is possible only when the biological equilibrium of a natural focus is infringed by mass appearance of small mammals or different bloodsucking arthropod species whose infection permits dissemination of the agent in the surrounding environment.