Читать книгу Principles of Virology, Volume 2 - Jane Flint, S. Jane Flint - Страница 33

The stories above highlight some of the unique challenges, uncertainty, and urgency that face epidemiologists during an outbreak. The study of viruses can be likened to a set of con centric circles. The center comprises detailed analyses at the molecular level of the genome and the structures of viral particles and proteins that are crucial to understanding viral re production, and the biochemical consequences of interactions of viral and host cell proteins. How infection of individual cells affects the tissue in which the infected cells reside, and how that impacted tissue disturbs the biology of the host, de fine the landscape of the field of viral pathogenesis, in the next level (discussed in the following four chapters). But if a viral population is to survive, transmission must occur from an infected host to susceptible, uninfected ones. The study of infections of populations is the discipline of epidemiology, the cornerstone of public health research and response. Within this broad, outer circle, major areas of epidemiological research include outbreak investigation, disease transmission, surveillance, screening, biomonitoring, and public education.

An epidemiologist investigates outbreaks by undertaking careful data collection in the field (that is, where the infections occur) and performing statistical analyses. Questions often asked include “How might the symptoms observed in an infected individual implicate one mode of viral transmission over another?” or “Can a timeline be established to trace back the origins of an epidemic to a single event?” The goal is to learn more about the pathogen and how it caused the epidemic. Individual differences among prospective hosts, group dynamics and behaviors, geography, and climate all influence how efficiently a virus can establish infection within a population. Epidemiologists lack the luxury of performing controlled experiments, in which only one variable is manipulated. Instead, they must consider many parameters simultaneously to identify the source and transmission potential of a viral pathogen within a host community. Many of these variables are captured in various video games and mobile phone apps that simulate outbreaks (Box 1.4). In the next section, we identify some crucial terms and concepts used in this field. (For commentary and a personal account related to the topic, see the interview with Dr. Thomas London: http://bit.ly/Virology_London.)