Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 28

Although viruses generally have a limited host range, they can and do spread across species barriers. As the world’s human population continues to expand and impinge on the wilderness, cross-species (zoonotic) infections of humans are occurring with increasing frequency. In addition to the AIDS pandemic, the highly fatal Ebola hemorrhagic fever, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS) are recent examples of viral diseases to emerge from zoonotic infections. The influenza virus H5N1 continues to spread among poultry and wild birds in areas of the Middle East and Asia. The virus is deadly to humans who catch it from infected birds. The frightening possibility that it could gain the ability to spread among humans is a major incentive for monitoring for person-to-person transmission in case of infection by this and other pathogenic avian influenza viruses. Given the eons over which viruses have had the opportunity to interact with various species, today’s “natural” host may simply be a way station in viral evolution.