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Experts speak on tackling COVID-19

A look into key aspects of virus pandemic

March 30, 2020 12:02 am | Updated 07:16 am IST

Dr. Sudha Seshayyan, Vice-Chancellor, Tamil Nadu Dr. MGR University, (left) and Dr. G. Srinivas, Head, Epidemiology department, Tamil Nadu Dr. MGR University.

Dr. Sudha Seshayyan, Vice-Chancellor, Tamil Nadu Dr. MGR University, (left) and Dr. G. Srinivas, Head, Epidemiology department, Tamil Nadu Dr. MGR University.

There are a lot of scientific terms being bandied about during the COVID-19 pandemic. Here’s a short primer on the key aspects everyone should be aware of.

What is ‘social distancing’?

‘Social distancing’ refers to a way of creating a barrier of physical distance between two or more people so that transmission of infectious agent can be prevented or halted. It may also be termed as physical distancing. It is a traditional public health measure of separating people to curb the outbreak of infectious disease, aimed to prevent person-to-person spread of disease to interrupt transmission and checking community transmission.

When does the need for social distancing occur?

Infectious diseases such as COVID-19, transmitted by respiratory droplets require a certain proximity of people. Social distancing reduces transmission, mitigates COVID-19 outbreak, particularly useful in settings where community transmission is believed to have occurred, but where the linkages between cases is unclear, and where restrictions placed only on persons known to have been exposed is considered insufficient to prevent further transmission.

What is ‘isolation’?

‘Isolation’ is the separation of ill persons with contagious diseases from non-infected persons to protect non-infected persons. This usually occurs in hospital settings. It is particularly effective in interrupting transmission if early detection is possible before overt viral shedding.

What is ‘quarantine’ ?

Quarantine demands movement restriction of persons who are presumed to have been exposed to a contagious disease but are not ill, either because they did not become infected or because they are still in the incubation period.

Quarantine may be applied at the individual or group level and usually involves restriction to the home or a designated facility. During quarantine, all individuals should be monitored for the occurrence of any symptoms. Quarantining is most successful in settings where detection of cases is prompt, contacts can be listed and traced within a short time frame with prompt issuance of quarantine. It is one of the oldest, most effective tools of controlling outbreaks & was implemented successfully as an effective measure during the SARS epidemic in 2003.

Is there evidence that physical distancing has been effective to control infectious disease?

Since the flu pandemic in September 1918, studies have showed the importance of distancing measures. Social distancing was the key in reversing the outbreak in Wuhan and the wider Hubei region. The earlier a lockdown is put in place in the epicentre of an outbreak, the smaller it ends up being.

Are ‘isolation & quarantine’ not a form of social distancing?

While isolation and quarantine are forms of social distancing, there is an important distinction to be made.

Isolation and quarantine are aimed at preventing people who are infected or are known to have had contact with people who are infected from passing on the virus.

Social distancing is a wider measure aimed at stopping the kind of mixing of people that allows infections to spread through a population. They range from ending mass gatherings, closing public spaces like educational establishments (schools, universities), gyms, museums, cultural and social centres, swimming pools and theatres and may be a total lockdown with people forced to stay indoors (community containment).

What are periods in the natural history of COVID-19 from public health angle ?

There are four periods:

1. Infected, but not contagious and not symptomatic.

2. Infected and contagious, but not symptomatic.

3. Infected, contagious, and symptomatic.

4. Recovering (assuming survival), where you may still have symptoms but are no longer contagious.

How does social distancing help in reversing the epidemic?

Even with an ignorance of who’s infectious, who's contagious, and how widespread the infection actually is, the social distancing can crush the exponential growth phase of COVID-19 & support reversing the transmission of the disease. One of the main aims of social distancing is to “flatten the curve”, which means delaying the spread of the virus so it reaches people more slowly.

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