What is World Zoonoses Day?
What are Zoonoses?
Why are the risks of Zoonotic Diseases increasing?
What are the impacts of zoonotic disease?
Zoonosis is derived from the Greek words zoon ‘animal’ and ????? nosos ‘ailment’.
Zoonosis (also spelled zoönosis and zoonoses) describes the process whereby an infectious disease is transmitted between species (sometimes by a vector) from animals other than humans to humans or from humans to other animals (the latter is sometimes called reverse zoonosis or anthroponosis). In direct zoonosis the agent needs only one host for completion of its life cycle, without a significant change during transmission.
In a systematic review of 1,415 pathogens known to infect humans, 61% were zoonotic.The emergence of a pathogen into a new host species is called disease invasion or ‘disease emergence’.
The emerging interdisciplinary field of conservation medicine, which integrates human and veterinary medicine, and environmental sciences, is largely concerned with zoonoses.
Most human prehistory was spent as groups of hunter-gatherers usually with fewer than 150 individuals that were not often in contact with other bands. Because of this, epidemic or pandemic diseases, which depend on a constant influx of humans who have not developed an immune response, tended to burn out after their first run through a population. To survive, a biological pathogen had to be a chronic infection, stay alive in the host for long periods, or have a non-human reservoir in which to live while waiting for new hosts to pass by. In fact, for many ‘human’ diseases, the human is actually an accidental victim and a dead-end host. (This is the case with rabies, anthrax, tularemia, West Nile virus, and many others). Thus, much of human development has been in relation to zoonotic, not epidemic, diseases.
The major factor contributing to the appearance of new zoonotic pathogens in human populations is increased contact between humans and wildlife. This can be caused either by encroachment of human activity into wilderness areas or by movement of wild animals into areas of human activity.
World Zoonoses Day images