COVID-19 Coronavirus Disease 2019 ,Just as the human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS), the coronavirus SARS-CoV-2 causes COVID-19. The symptoms of COVID-19 include cough, fever, and shortness of breath. While the disease appears to cause mild to moderate illness in most people, in others it has caused life-threatening pneumonia and death. Doctors and researchers continue to learn more about the disease, so information about symptoms, prevention, and treatment may change as more data becomes available.
Spread of disease
When a disease—and the virus that causes it—begins to spread, epidemiologists (who are considered the basic scientists of public health) take notice, looking for the frequency, patterns, and causes associated with it. Below are definitions of a few of those epidemiological terms that you may hear or see reported in the news, especially as they relate to COVID-19.
The baseline, or expected, level of the disease in the community—meaning it always exists, like the common cold and flu, which are usually at low, predictable rates. Buy Covid-19 Vaccine Card Online .
This refers to a sudden increase in the number of cases of a disease, above what is typically expected in a particular area. COVID-19 is thought to have reached epidemic proportions in China in mid-January. “There is not really a date because there is no background [endemic] activity of this novel coronavirus in humans,” says Dr. Meyer. Buy Covid-19 Vaccine Card Online .
This shares the same definition as epidemic, with one exception—an outbreak usually refers to a more limited geographic area. COVID-19 started as an outbreak in Wuhan, the capital city of the Hubei province in China at the end of December 2019, when the Chinese government confirmed that it was treating dozens of cases of pneumonia of unknown cause.
An epidemic that has spread over several countries or continents, impacting many people. Pandemics typically happen when a new virus spreads easily among people who—because the virus is new to them—have little or no pre-existing immunity to it. COVID-19, which was declared a pandemic by the WHO in early March, is the first pandemic known to be caused by the emergence of a new coronavirus. Buy Covid-19 Vaccine Card Online .
The CDC recognizes six stages to a pandemic—it starts with an investigation phase, followed by recognition, initiation, and acceleration phases, which is when it peaks. Then, comes a deceleration phase, when the rate of infection decreases. Finally, there is a preparation phase, where the pandemic has abated, and public health officials monitor virus activity and prepare for possible additional waves of infection. Different countries—and various sections of the same country—can be in different phases of the pandemic at the same time. The U.S. is currently in the acceleration phase.