Annals of Clinical Trials and Vaccines Research

Epidemology : Viral Diseases

Epidemiology is the study of the distribution, the dynamics, and the determinants of diseases in populations. The risk of virus infection and/or disease in a human population is determined by the characteristics both of the virus, and of susceptible individuals and of the host population such as innate and acquired resistance. In addition, virus transmission is affected by behavioral, environmental, and ecological factors. Virus epidemiology aims to meld these factors using quantitative measurements to provide a rational basis for explaining the occurrence of virus diseases and for directing disease-control measures, in particular the identification of outbreak sources and how best to implement prevention strategies. Epidemiology can also help to clarify the role of viruses in the etiology of diseases, understanding the interaction of viruses with environmental determinants of disease, determining factors affecting host susceptibility, clarifying modes of transmission, and the testing of vaccines and therapeutics on a large scale. Because viruses, unlike most bacteria, cannot replicate outside of living cells, perpetuation of a virus in nature depends on the maintenance of serial infections, that is, a chain of transmission; the occurrence of disease is neither required nor necessarily advantageous. Indeed, although clinical cases may often produce more infectious virus than inapparent infections, the latter are generally more numerous and, because these do not restrict the movement of infectious individuals, they can provide a major mechanism of viral dissemination. Epidemiologists recognize three different patterns of virus survival in mammalian hosts, distinguished through use of virus reservoirs: acute self-limiting infections with no reservoir, persistent infections with a reservoir in humans, and involvement of an animal reservoir.    

High Impact List of Articles

Relevant Topics in General Science