Читать книгу Principles of Virology, Volume 2 - Jane Flint, S. Jane Flint - Страница 99

Viremia is a common feature of many viral infections, and exposure to viremic blood is a primary mode of virus trans mission. Insects acquire virus particles when they bite viremic hosts and may transmit them to subsequent hosts with the next blood meal. This, however, is not true for all blood-borne viruses: for example, human immunodeficiency virus type 1 cannot be transmitted by mosquitos. Hepatitis viruses and human immunodeficiency virus type 1 can be transmitted by virus-laden blood during transfusions and injections. Virus particles may also be transmitted from blood during sexual intercourse or childbirth, and consumption of raw meat may place contaminated blood in contact with the alimentary canal and respiratory tract. Health care professionals, emergency rescue workers, and dentists are exposed routinely to blood from individuals who may harbor infections. Indeed, for many of the viruses that cause fatal hemorrhagic fevers (such as members of the Bunyaviridae and Filoviridae), the primary mode of transmission to humans is via contaminated blood and body fluids. Consequently, health care workers often are among the first to become infected and show symptoms in an outbreak of such viral diseases.