History and Epidemiology

Abstract

In December of 2019, a cluster of cases of atypical pneumonia in Wuhan China caught the attention of infectious disease investigators in China. In a short span of time, more cases emerged without any identifiable source. Genetic sequencing identified the culprit pathogen as that of a novel coronavirus. The virus was named SARS-CoV-2, and within 100 days, that virus had spread across the globe causing a pandemic of proportions that were unprecedented in modern times. The novel coronavirus is genetically similar to two other coronaviruses responsible for large outbreaks: SARS-CoV, responsible for the Severe Acute Respiratory Syndrome outbreak of 2002, and MERS-CoV, responsible for the 2012 outbreak of Middle East Respiratory Syndrome. The clinical criteria for SARS-CoV-2 infection are acute onset of fever and cough or any three of the following: fever, cough, general weakness/fatigue, headache, myalgia, sore throat, coryza, dyspnea, anorexia/nausea/vomiting, diarrhea, or altered mental status. Transmission of the virus occurs primarily by person-to-person contact with droplet particles. Though contact tracing has proven difficult due to a number of asymptomatic carriers, control of the spread has also been complicated by the emergence of a number of variants. As the status of the pandemic evolves, it is clear that controlling the spread of the virus is going to rely on the ongoing coordinated efforts of scientists, healthcare professionals, and animal researchers across the globe.