Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 20

Viruses are all around us, comprising an enormous proportion of our environment, in both number and total mass (Box 1.1). All living things encounter billions of virus particles every day. For example, they enter our lungs in the 6 liters of air each of us inhales every minute; they enter our digestive systems with the food we eat; and they are transferred to our eyes, mouths, and other points of entry from the surfaces we touch and the people with whom we interact. Viral nucleic acids (the virome) can be found in the respiratory, gastrointestinal, and urogenital tracts even of normal, healthy individuals (Fig. 1.1). Our bloodstreams harbor up to 100,000 virus particles per milliliter. In addition to viruses that can infect us, our intestinal tracts are loaded with myriad plant and insect viruses, as well as many hundreds of bacterial species that harbor their own constellations of viruses.