Confused about all the terminology surrounding the coronavirus? These terms and definitions can help.
Coronavirus: Starting with the most obvious, this word refers to a family of hundreds of similarly shaped viruses. Under a microscope, they look like round blobs surrounded by spikes, much like the corona, or crown, surrounding the sun. There are seven coronaviruses that can affect people. The common cold is one, as are its more virulent cousins: SARS, severe acute respiratory virus, and MERS, Middle East respiratory virus.
COVID-19: This is the disease caused by the coronavirus. The first four letters are taken from the word coronavirus and then the "d" from disease. The number 19 indicates it started in 2019. The disease is officially named SARS-CoV-2, because it is a respiratory virus, but you will hear people use all of these terms interchangeably.
Cluster: Epidemiologists refer to a group of cases of the same disease or condition in a particular area as a cluster. For example, there may be a cluster of birth defects in places that contain large amounts of toxic chemicals. Where there are clusters of conditions, scientists can investigate and find out the cause. As the numbers of people with a particular disease increase, it could then become an outbreak.
Community transmission versus person-to-person spread: Dr. Anthony Fauci with the U.S. National Institutes of Health explains that "community transmission" means the disease is spreading to someone who has not had close contact with an infected person and had not visited a place where the virus is known to be spreading. It's a mystery until scientists figure out how the disease spreads. Person-to-person spread is just what it sound like - the disease is spread to whose who are in close contact with one another, such as family members.
Epidemic, pandemic and outbreak: An outbreak is a sudden surge in the number of people coming down with a particular disease. An epidemic is a very large outbreak that has spread to other regions, countries or continents. A lot of doctors using these terms almost interchangeably. If a disease is called a pandemic, it can't be controlled, but that doesn't necessarily mean that a lot of people are dying. The last pandemic was in 2009 when a new influenza virus, called H1N1, started in the U.S. and circulated the globe. The U.S. Centers for Disease Control and Prevention estimates that between 151,000 and 600,000 people died.
Fatality rate: The number of people who die from a disease. The World Health Organization (WHO) says the fatality rate from COVID-19 is around 3.4% and that people over 60 and those with other health problems are far more at risk than those who are younger. Eighty percent of people who get the coronavirus don't need hospitalization and can recover at home with no problem. SARS had a fatality rate of 9.6%, for MERS, it was 34.4%.
Asymptomatic and symptomatic: When someone is asymptomatic, they don't show any signs of being sick, but they have the virus and can spread it to others. When someone is symptomatic, that person has visible signs of being sick. With COVID-19, that means a cough, fever and difficulty breathing. The intensity of these symptoms vary from person to person, but health experts say the most common way the new coronavirus spreads is between someone who has the disease and is showing the symptoms and another person.
Isolation versus quarantine: Isolation means a person, sick or not, stays away from other people. Older adults may want to self-isolate at home for the duration of the coronavirus outbreak. This means they would not go outdoors except when necessary or go to group events. Hospitals may have isolation units to keep infected people away from those who don't have the virus. Isolation is intended to keep the virus contained or keep a healthy person well.
With a quarantine, people who may have been exposed to a virus are prevented from leaving a particular area. China quarantined entire cities as the coronavirus spread. Other countries quarantined their citizens who returned from China. Americans evacuated from Wuhan and cruise ships were housed on military bases while doctors evaluated them for signs of the coronavirus.
Therapeutics: Treatments used to help people get over a disease or to prevent them from getting one. There are now treatments for Ebola and HIV. Therapeutics could include drugs and medical devices, or other types of treatments. There are no therapeutics for COVID-19 so doctors treat the symptoms. For example, they provide drugs to reduce a fever or put a patient who is having trouble breathing on oxygen.
Anti-viral medicine: Any medicine that fights a virus. Biotech company Gilead Sciences is testing the antiviral drug remdesivir in China as a possible treatment for the new coronavirus. Remdesivir was developed to treat Ebola.