Unless you have been on a remote island with no access to the internet (if so, you should have stayed there!), several new words will have been added to your vocabulary in the past few months. Terms such as case fatality rate, antibody, and PPE are no longer just used by scientists. Consider this your coronavirus jargon-buster.
ACE2: A protein on the cells in your airways that coronavirus attaches to.
Antibody: Large Y-shaped proteins that stick to the surface of bacteria and viruses.
Antigen: A foreign substance that induces an immune response in the body – especially the production of antibodies.
Case fatality rate: The percentage of confirmed cases that resulted in death is the case fatality rate, or CFR. The World Health Organization estimates the CFR for COVID-19 to be about 3.4%. But this number is likely to come down as more tests are performed and we identify more of the large number of cases with no symptoms. In South Korea, where lots of testing was performed, the CFR is about 1.5%.
COVID-19: The disease, not the virus that causes the disease. That’s SARS-CoV-2 (see below).
Endemic: Not to be confused with “epidemic”. A disease that is regularly found among a particular group or in a particular region, such as malaria.
Epidemic: The widespread occurrence of an infectious disease in a population at a particular time. So COVID-19 is a pandemic (because of its global spread), but it is also an epidemic in the UK, for example.
Flattening the curve: Hospitals can only cope with so many patients. Flattening the curve is an attempt to reduce how many cases of COVID-19 occur at the same time so that hospitals aren’t overwhelmed.
Herd immunity: When a large number of people in a population are immune to a disease, either through vaccination of through having the disease naturally, it is difficult for that disease to spread. For highly infectious disease, such as measles, if 95% of the population is vaccinated, the number of cases of the disease will be dramatically reduced and can even be wiped out. For COVID-19, which is less infectious than measles, herd immunity would work if around 60%-70% of the population was vaccinated.
Incubation period: This is the length of time between being infected and showing symptoms. Most people show symptoms within five days of being infected within SARS-CoV-2, but it can take up to two weeks.
N95 mask: These are also called respirator masks. All the air being breathed in passes through a filter which reduces the chances of someone be infected. These masks only work if they fit properly. They do not work if you have any facial hair, so you’re unlikely to see many bearded doctors.
Pandemic: When many people in several countries on several continents have a disease. COVID-19 is considered a pandemic with over 203 countries and territories reporting confirmed cases.
Patient zero: Not a medical term and one that is stigmatising. Best avoided. In medicine, we usually refer to an “index case”, but that’s something different. It refers to the first known case of a disease.
PCR test: This is the test used to find out if you have a COVID-19 infection (contrast with serological test). It’s a genetic test. A swab is taken from the mucous membrane lining your nose and throat. Any RNA (the genetic instructions contained within the virus) samples are turned into DNA using an enzyme called reverse transcriptase. The DNA is then amplified in a process called polymerase chain reaction – hence PCR. This test can take hours to get a result, but several companies are trying to develop rapid molecular testing methods.
Pre-print: A research paper that is yet to be peer-reviewed. There are published in “pre-print servers”, such as BioRxiv and MedRxiv, and are free for anyone to access. Usually, research that hasn’t been reviewed by other experts in the field is frowned upon, but in a rapidly growing and evolving crisis, such as the current one, they serve a very useful purpose.
PPE: No, not mis-sold insurance. This is personal protective equipment. Stuff front-line healthcare staff need to keep them safe. Things like masks, disposable gloves and goggles. The level of protection that PPE needs to provide is different depending on how risky the activity being performed is.
Reagent: A reagent is any chemical needed to conduct an experiment. Like an ingredient in a recipe. There has been a lot of talk about reagents in the press lately as it is one of the “ingredients” needed to make the COVID-19 tests.
R0 (pronounced R nought): The average number of people a sick person will infect. And the word “average” here is key because, depending on how many people are being tested and how many cases are identified, the R0 will change. The R0 of SARS-CoV-2 is between two and three, meaning that each infected person will infect two or three other people. This is why it can spread so quickly.
SARS-CoV-2: The virus that causes COVID-19. Initially named 2019-nCoV by the World Health Organization (which caused a lot of confusion), but later given its official moniker by the people actually in charge of naming viruses: the Coronavirus Study Group (CSG) of the International Committee on Taxonomy of Viruses (yeah, we don’t go for snappy names in biology).
Serology test: Blood tests that look for the presence of antibodies that indicate if someone has already been exposed to a disease. These tests will not work early in an infection, it takes some time for our bodies to start producing the antibodies against the virus.
Super spreader: A pejorative term for someone who infects lots of people with the disease they have. It sounds like a medical term, but it’s not. It’s also stigmatising and shouldn’t be used – by anyone.
Lindsay Broadbent receives funding from The Wellcome Trust.