This slide was used for a lecture of 9th Asian Society of Conservation Medicine(ASCM) in Taipei, October 22nd, 2016. Generally, virus researcher for zoonosis works with 1 or 2 specific virus or disease. Therefore, it is difficult to overview of all kind of viruses causing zoonoses (zoonotic viruses).

     Here, I will try to characterize the zoonotic viruses when compare with character of non-zoonotic viruses. Why several viruses are so easily overcome host species barrier, but others do not? What is a difference between RNA and DNA, double stranded and single stranded, bigger genome size and smaller genome size, segmented and non segmented genome etc.?

      The result is important to conduct the risk based surveillance for wildlife,

especially to determine the priority and hazard analysis.



Our sustainable world supported by invisible microorganisms.


The Sun and the Earth was born about 4.6 billion years ago. The first life emerged about 3.7 to 4 billion years ago as anaerobic autotrophic bacteria group. About half of the life history of 4 billion years on the Earth is the world of bacteria. Eukaryotic organism appeared about 2 billion years ago, and protozoa and algae were the highest creatures during about 1 billion years. Thereafter, multi-cellular organism group appeared about 1 billion years ago, and higher multi-cellular organisms appeared after the pre-Cambrian era about 500 to 600 million years ago. They evolved vertebrates eventually as fish, amphibians, reptiles, birds, and mammals.


This is the Earth's life history, but now the Earth has not changed the situation. Animals are not able to create a nutrition by themselves. Sugar and oxygen to become a source of energy for animal, are produced by the plant. Energy from the Sun is needed to plant photosynthesis, and carbon dioxide is discharged from the animal's breath. Circulation of energy

between plants and animals has created a sustainable situation. However, this is the visible energy circulation.


The nitrogen occupying 80 percent in the air is metabolized by nitrogen-fixing bacteria in soil such as rhizobia, and it will be used in the nutrition of the plant. The nitrogen will be returned from the soil or water to the air by the denitrifying bacteria. The same is true for phosphorus. Oxygen is also created by various algae and cyanobacteria, as well as plants. Algae and bacteria become the food for plankton and protozoa, and then plankton and small fish are eaten by larger fish. The fishes will be for human consumption as fisheries resources. Livestock and poultry also produce meat, eggs and milk, and they will be in service for human consumption. Such as food residue and livestock manure are the nutrient source for plants and soil bacteria as compost. Using the fermentation bacteria in the biomass will be used in methane and ethanol production. In this way, the atmosphere, water and soil are built, and are maintained on the foundation of the invisible bacteria, archaea, fungi and protists. Even now, the activity is continuing by bacteria (intestinal bacteria with a history of 4 billion years), and protists (environmental protists with a history of 2 billion years). Animals, plants and humans are able to keep alive on top of their activities.



However, environmental pollution goes rapidly by recent human activities, and it is approaching the self-cleaning and regeneration capacity limit. The Earth is only one star which has the life form in the neighboring space, and mankind has a responsibility for continuous protection of this star. The Earth is the common living home for all species and the human being (One World). Before passing the irreparable baton of the excessive burden to the next generation, what we must do? We need to know the secret of the playback mechanism and the resources circulation, which is conducted on this planet by both microorganisms and higher organisms. In addition, we need to find both crisis management and biological-measures, which enable the coexistence and harmony.