Emerging Viruses and Epidemics

Abstract

To understand the scope and importance of a viral epidemic, we first must expand upon what an epidemic is. The normal disease or infection prevalence in a geographic location is referred to as the endemic level. Endemic infections or diseases are typically always present in a population, whereas sporadic infections or diseases can emerge infrequently and unpredictably. When a pathology is considered hyperendemic, this means that the disease is seen consistently and in high levels¹. An example of an endemic virus is dengue, which has become endemic in almost all of South America due to the rapid spread of the viral carrier, a species of mosquito called Ae. Aegypti³. Simply, an epidemic indicates a rapid increase in the number of reported cases of a disease or infection in an area, far above what is considered endemic¹. A viral epidemic, then, refers to a sudden increase in reported cases of a virus.

For example, in 1901 there was a smallpox epidemic in Boston that resulted in 1,500 reported cases and 270 deaths. Most recently, the CDC has declared that the Zika virus was a public health emergency due to its rapid expansion in North and South America after its original discovery in Uganda². Though the term “viral epidemic” may spur thoughts of the Spanish Influenza or Smallpox outbreaks that killed or otherwise seriously affected millions, outbreaks do not have to reach these staggering numbers to be considered an epidemic. In fact, it is much more beneficial to declare a public health emergency and garner scientific interest before it reaches these disastrous levels.