The study, published in the journal PNAS, assessed about 60 super-spreading events.(Pixabay)
The study, published in the journal PNAS, assessed about 60 super-spreading events.(Pixabay)

Covid-19 super-spreading events play ‘outsized role’ in disease transmission, say scientists

Covid-19 super-spreading events, in which one person infected with the novel coronavirus transmits it to many other people, play an “outsized role” in the overall spread of the disease.
By Press Trust of India | Posted by Jahnavi Gupta | Boston
UPDATED ON NOV 03, 2020 07:42 PM IST

Covid-19 super-spreading events, in which one person infected with the novel coronavirus transmits it to many other people, play an “outsized role” in the overall spread of the disease, according to a new study which says preventing large gatherings could significantly curb the pandemic.

The study, published in the journal PNAS, assessed about 60 super-spreading events, revealing that events where one person infects more than six other people are much more common than would be expected if the transmission patterns followed statistical distributions commonly used in epidemiology.

Based on their findings, the scientists, including those from the Massachusetts Institute of Technology (MIT) in the US, developed a mathematical model of Covid-19 transmission, which they used to show that limiting gatherings to 10 or fewer people could significantly reduce the overall number of infections.

“Super-spreading events are likely more important than most of us had initially realised. Even though they are extreme events, they are probable and thus are likely occurring at a higher frequency than we thought,” said James Collins, senior author of the new study.

“If we can control the super-spreading events, we have a much greater chance of getting this pandemic under control,” Collins said.

For the novel coronavirus, the scientists said the “basic reproduction number” is around three, meaning that on average, each person infected with the virus spreads it to about three other people.

However, they said this number varies widely from person to person, with some who don’t spread the disease to anyone else, while “super-spreaders” infect dozens of individuals.

“We figured that an analysis that’s rooted in looking at super-spreading events and how they happened in the past can inform how we should propose strategies of dealing with, and better controlling, the outbreak,” said Felix Wong, another study co-author from MIT.

In the research, the scientists defined super-spreaders as individuals who passed the virus to more than six other people. Using this definition, they identified 45 super-spreading events from the current Covid-19 pandemic, and 15 additional instances from the 2002-03 SARS pandemic outbreak, all documented in scientific journal articles. According to the researchers, during most of these events, between 10 and 55 people were infected, but two of them, both from the 2003 outbreak, involved more than 100 people.

Typically, events in which the disease spreads to dozens of people would be considered very unlikely, they said.

However, the MIT team found that this was not the case for coronavirus super-spreading events. The scientists found that even though super-spreading events are extreme, they are still likely to occur.

“This means that the probability of extreme events decays more slowly than one would have expected,” Wong said.

“These really large super-spreading events, with between 10 and 100 people infected, are much more common than we had anticipated,” he added.

According to the researchers, many factors may contribute to making someone a super-spreader, including their viral load and other biological factors.

They did not address these factors in this study, but the scientists modelled the role of connectivity -- defined as the number of people that an infected person comes into contact with.

In order to study the effects of connectivity, the scientists created and compared two mathematical network models of disease transmission. In each, the average number of contacts per person was 10, but they designed one model to have an exponentially declining distribution of contacts, while in the other, some people had many contacts.

The researchers found that in the latter model, many more people became infected through super-spreader events.

However, the study noted that the transmission stopped when people with more than 10 contacts were taken out of the network and assumed to be unable to catch the virus.

Based on the results, the researchers said preventing super-spreading events could have a significant impact on the overall transmission of Covid-19.

“It gives us a handle as to how we could control the ongoing pandemic, which is by identifying strategies that target super-spreaders,” Wong said.

“One way to do that would be to, for instance, prevent anyone from interacting with over 10 people at a large gathering,” he added.

(This story has been published from a wire agency feed without modifications to the text.)

Follow more stories on Facebook and Twitter

SHARE THIS ARTICLE ON
app
Close
Treating severe Covid-19 patients with the arthritis drug tocilizumab along with standard care is no better than standard care alone in improving clinical outcomes at 15 days, says the results of a trial.(Unsplash)
Treating severe Covid-19 patients with the arthritis drug tocilizumab along with standard care is no better than standard care alone in improving clinical outcomes at 15 days, says the results of a trial.(Unsplash)

Arthritis drug no better than standard care for severe Covid-19, says study

PTI
PUBLISHED ON JAN 21, 2021 05:31 PM IST
Treating severe Covid-19 patients with the arthritis drug tocilizumab along with standard care is no better than standard care alone in improving clinical outcomes at 15 days, says the results of a trial which was stopped early due to increased number of deaths among those receiving the drug.
Close
Representational Image(Unsplash)
Representational Image(Unsplash)

New tool helps calculate Covid transmission risk in poorly-ventilated places

PTI
PUBLISHED ON JAN 21, 2021 04:27 PM IST
The research also shows that the virus spreads further than two meters in seconds in poorly-ventilated spaces.
Close
Katrina Kaif does Pilates in new fitness video(Instagram/katrinakaif)
Katrina Kaif does Pilates in new fitness video(Instagram/katrinakaif)

Katrina Kaif is the latest Pilates fan, shares new video from rigorous session

By Nishtha Grover, Delhi
PUBLISHED ON JAN 21, 2021 04:15 PM IST
  • Katrina Kaif recently shared a video from her extreme Pilates session. Looking radiant in a bright red co-ord set, the actor inspired us to stop procrastinating and hit the gym.
Close
A new study lead by researchers from Northwestern University highlights the importance of getting a deep sleep for good brain health.(ANI)
A new study lead by researchers from Northwestern University highlights the importance of getting a deep sleep for good brain health.(ANI)

Study: Deep sleep prevents neurodegenerative disease, crucial for brain health

ANI
PUBLISHED ON JAN 21, 2021 01:39 PM IST
A new study lead by researchers from Northwestern University highlights the importance of getting a deep sleep for good brain health.
Close
Scientists are reporting troubling signs that some recent mutations of the virus that causes Covid-19 may modestly curb the effectiveness of two current vaccines, although they stress that the shots still protect against the disease.(AP)
Scientists are reporting troubling signs that some recent mutations of the virus that causes Covid-19 may modestly curb the effectiveness of two current vaccines, although they stress that the shots still protect against the disease.(AP)

Some Covid-19 mutations may dampen vaccine effectiveness

AP
PUBLISHED ON JAN 21, 2021 12:09 PM IST
Scientists are reporting troubling signs that some recent mutations of the virus that causes Covid-19 may modestly curb the effectiveness of two current vaccines, although they stress that the shots still protect against the disease.
Close
Without herd immunity as a shared goal, some might skip the vaccine, influenced by scare stories about side effects and rare allergic reactions, especially if they are young and face only a small chance of dying from the virus.(Pixabay)
Without herd immunity as a shared goal, some might skip the vaccine, influenced by scare stories about side effects and rare allergic reactions, especially if they are young and face only a small chance of dying from the virus.(Pixabay)

Herd immunity could be closer than we think

Bloomberg
PUBLISHED ON JAN 21, 2021 11:55 AM IST
The evidence is compelling that a strong, rapid vaccination campaign could render SARS-CoV-2 less of a threat than seasonal flu through building herd immunity.
Close
A study clarifies which gene may raise breast cancer risk(AP)
A study clarifies which gene may raise breast cancer risk(AP)

New studies clarify which genes may raise breast cancer risk

AP
PUBLISHED ON JAN 21, 2021 11:34 AM IST
Two large studies give a much sharper picture of which inherited mutations raise the risk of breast cancer for women without a family history of the disease, and how common these flawed genes are in the general population.
Close
Larger trials are needed to assess whether Roche's arthritis drug tocilizumab can cut death rates among the sickest Covid-19 patients, scientists said on Wednesday, after a small study found it was no better than standard care in severe cases.(Yahoo)
Larger trials are needed to assess whether Roche's arthritis drug tocilizumab can cut death rates among the sickest Covid-19 patients, scientists said on Wednesday, after a small study found it was no better than standard care in severe cases.(Yahoo)

Conflicting Covid-19 results for Roche arthritis drug show more trials needed

Reuters
PUBLISHED ON JAN 21, 2021 11:05 AM IST
Larger trials are needed to assess whether Roche's arthritis drug tocilizumab can cut death rates among the sickest Covid-19 patients, scientists said on Wednesday, after a small study found it was no better than standard care in severe cases.
Close
A study published by the British Medical Journal (BMJ) provides evidence that stimulant medications are generally inadequate for back and osteoarthritis pain, in spite of being broadly utilized for these conditions.(Unsplash)
A study published by the British Medical Journal (BMJ) provides evidence that stimulant medications are generally inadequate for back and osteoarthritis pain, in spite of being broadly utilized for these conditions.(Unsplash)

Antidepressants ineffectual for back pain and osteoarthritis

ANI
PUBLISHED ON JAN 21, 2021 10:46 AM IST
A study published by the British Medical Journal (BMJ) provides evidence that stimulant medications are generally inadequate for back and osteoarthritis pain, in spite of being broadly utilized for these conditions.
Close
Scientists find breakthrough in understanding 'tummy bug' bacteria (representative image)(Unsplash)
Scientists find breakthrough in understanding 'tummy bug' bacteria (representative image)(Unsplash)

Scientists find how bacteria causes gastroenteritis after eating raw sea food

ANI, Washington
PUBLISHED ON JAN 21, 2021 08:56 AM IST
Scientists recently found the marine bacteria that is responsible behind an upset stomach after eating raw or undercooked shellfish such as oysters and mussels.
Close
Want to get your stamina back post Covid? Check out Varun Dhawan’s fitness video(Instagram/varundvn)
Want to get your stamina back post Covid? Check out Varun Dhawan’s fitness video(Instagram/varundvn)

Want to get your stamina back post Covid? Check out Varun Dhawan’s fitness video

By Zarafshan Shiraz
UPDATED ON JAN 20, 2021 04:28 PM IST
  • From right side lateral travelling ape to full scorpion, here’s how Coolie No.1 star Varun Dhawan recovered and got his stamina back after suffering from Covid-19 | Watch
Close
A study published in journal Human Gene Therapy shows that gene editing therapies, including CRISPR-Cas frameworks, offer the possibility to address transformations causing inherited retinal degenerations, a leading cause of blindness.(ANI)
A study published in journal Human Gene Therapy shows that gene editing therapies, including CRISPR-Cas frameworks, offer the possibility to address transformations causing inherited retinal degenerations, a leading cause of blindness.(ANI)

Study highlights genome altering can help to treat human retinal degeneration

ANI
PUBLISHED ON JAN 20, 2021 03:35 PM IST
A study published in journal Human Gene Therapy shows that gene editing therapies, including CRISPR-Cas frameworks, offer the possibility to address transformations causing inherited retinal degenerations, a leading cause of blindness.
Close
Representational image(Unsplash)
Representational image(Unsplash)

Loss of smell may be best predictor of Covid-19, research confirms

PTI
PUBLISHED ON JAN 20, 2021 02:48 PM IST
The research found that only around half of patients with a loss of smell got their sense of smell back after forty days.
Close
During the pandemic, burnout among health care professionals is a pervasive public health concern as the health care professionals are required to work even longer hours in high-stress situations.(ANI)
During the pandemic, burnout among health care professionals is a pervasive public health concern as the health care professionals are required to work even longer hours in high-stress situations.(ANI)

Burnout among health care professions a public health concern during pandemic

ANI
UPDATED ON JAN 20, 2021 02:19 PM IST
During the pandemic, burnout among health care professionals is a pervasive public health concern as the health care professionals are required to work even longer hours in high-stress situations.
Close
Representational image(WebMD)
Representational image(WebMD)

Fatty acid may combat multiple sclerosis. Here's how

ANI
UPDATED ON JAN 20, 2021 12:36 PM IST
A new study by Yale University explains that the abnormal immune system response that causes multiple sclerosis (MS) by attacking and damaging the central nervous system can be set off by the lack of a specific fatty acid in fat tissue.
Close
SHARE
Story Saved
OPEN APP