As coronavirus cases in India inch toward 50,000-mark, it is more important than ever to understand the disease and the terms commonly used to explain its symptoms, spread and containment measures.
Terms like community transmission, contact tracing, quarantine etc. are often used in news and discussions around Covid-19. To fathom better how the highly-infectious novel coronavirus works, here are the key terms you should know.
Close Contact: A person who bears a high-risk of contracting Covid-19 because of being closer than six feet to an infected person for a long period of time.
Incubation Period: The time between exposure to the virus and onset symptom in the infected person. According to WHO, the incubation period is on average 5-6 days, however, it can be up to 14 days.
Symptomatic: A symptomatic COVID-19 case is where a person develops signs and symptoms of the COVID-19 virus infection. Symptomatic transmission refers to transmission from a person while they are experiencing symptoms, according to the WHO. Research shows that COVID-19 is primarily transmitted from symptomatic people to others who are in close contact through respiratory droplets or by contaminating objects and surfaces which are touched by others.
Pre-symptomatic: The incubation period of the virus in a person who has not started showing symptoms is known as the pre-symptomatic period. Some infected persons can be contagious during this period.
Asymptomatic: An asymptomatic case is a covid-positive person who does not develop symptoms in the course of the infection. Such cases are only detected by tests and often found during contact tracing.
Contact Tracing: A key to fight the virus spread, contact tracing is the process of finding each person who recently interacted with a Covid-positive person. When a person tests positive, public health officials interview them to get a list of people who had close interacions with the infected persons and thus, could have been exposed to the virus. Then these contacts are made to self-isolate, monitor themselves for possible symptoms or quarantine. If someone from the list shows symptoms and tests positive, his/her contacts will be further traced.
Self-Isolation: Staying indoors and avoiding any contact with other people. This is for people who test positive for Covid-19, are suspected of being infected or waiting for test results.
Quarantine: When people are not sick with the virus but are required to stay in isolation from the society because of possible or known exposure to Covid-19. This is pescribed for people undertaking on interstate or overseas travel, so that they don't end up infecting the healthy population. Quarantine generally lasts for 14 days (the incubation period for the virus) or more.
Cluster Cases: A cluster happens is when an aggregation of cases is found in an identifiable group of people linked by space (such as area of residence, work, or other setting) and time of onset of the disease in them.
Community and Local Transmission: Community transmission is where there are large numbers of local transmissions occurring and a direct source of exposure cannot be identified, making it difficult to contain the spread. This differs from the local transmission, where a person acquires COVID-19 locally, and a direct source may or may not be identifiable.
Dysgeusia: A symptom of Covid-19 infection where the person loses the sense of taste.
Anosmia: Another symptom of Covid-19 where the infected person loses the sense of smell.
Epidemiology: It is the study the emergence, sprad and control of a disease among groups of people.
Herd Immunity: When a large part of an area or a community become immune to an infectious disease, which effectively stops the disease from spreading and protects the entire community.
