Why COVID Super Spreaders Can Still Infect and Lead to Isolation

People with high viral loads can spread SARS-CoV-2 on a larger scale than usual in a single event or meeting. Details of the officials meeting in Washington that ignited the alert

FILE PHOTO: Travelers form lines outside the TSA security checkpoint during the holiday season as the new coronavirus disease (COVID-19) Omicron variant threatens to increase case numbers at Hartsfield-Jackson Atlanta International Airport in Atlanta, Georgia, U.S. December 22, 2021. REUTERS/Elijah Nouvelage/File Photo

Washington Mayor Muriel Bowser reported that she became infected with COVID-19 last week. The news became even bigger as Bowser was infected with a significant number of officials and politicians after participating in a meeting with officials, suggesting that infections at public events exist and that coronavirus super-propagators may be among us.

Washington health authorities confirmed that a small outbreak of the disease is taking place in high political circles in Washington after a dinner at the Gridiron Club. More than a dozen attendees at the event — including two cabinet members, journalists and legislators — have tested positive. Pandemic numbers in Washington have increased slowly last month, but are far from reaching the January peak of the Ómicron variant, and Bowser has lifted most restrictions in the US capital.

The superspread of COVID-19, which involves the virus spreading in a single event on a larger scale than is normally expected, is still possible and poses a general risk to the population. But at this stage of the pandemic, a major event may not necessarily be an invitation to a widespread and uncontrolled disease, if people use the tools available now to limit risk, according to public health experts.

Now, there are more tools to slow the spread of Covid-19: licensed vaccines that limit disease and infection, robust home testing supplies that can tell if someone needs to isolate themselves, face masks for use in high-risk situations, and therapies that can reduce serious illness.

We used to be worried that these superpropagation events would put many people in the hospital and, as a result, some in intensive care units and even some people dying. This is less likely to happen now. Given the level of natural immunity, as well as vaccination in our communities, most infected people will now get a mild illness that does not require them to be hospitalized,” said Dr. William Schaffner, professor in the Division of Infectious Diseases at Vanderbilt University Medical Center.

Meanwhile, it is also more complicated to link coronavirus cases to specific events. Contact tracing is virtually gone, and people can encounter COVID-19 just around the corner in any circumstance as workplaces, shops and restaurants return to open and remove masks or masks.

However, using the right tools at the right times, there is hope that the superspread of Covid-19 will become a thing of the past.

'The pandemic is not over'

The Director-General of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, insisted that the COVID pandemic remains a global threat, despite the decline in deaths and the shift in media attention to events such as the current Russian invasion of Ukraine.

“We all want to leave the pandemic behind us, but no matter how much we want it, it's not over yet,” said the Ethiopian expert at his weekly press conference, stressing that the wave of infections in Asia, coupled with the surge in cases in Europe, is causing global positive figures to rise again, after a month of declines.

At the same time, “some countries are suffering their highest mortality rates since the start of the pandemic,” warned the WHO chief, asserting that this reflects the speed at which the Ómicron variant is able to be transmitted and how dangerous it remains, “especially for unvaccinated older people”.

Events and super propagation

At the beginning of the current pandemic, the superspread at business conferences, political events and even any closed arena helped to understand how transmissible the coronavirus could be. An example in the US is recalled when 200 people attended a biotechnology conference in late February 2020 that was linked to some 20,000 cases of COVID-19 in the Boston area, according to research by the Broad Institute at MIT, Harvard University.

A report released by the US Centers for Disease Control and Prevention in May 2020 described how a symptomatic person with COVID-19 attended a choir practice in Washington State and then about 87% of the other choir members developed the disease. But those superpropagation events occurred before it became clear exactly how the virus spread and who was most at risk, and long before COVID-19 vaccines were available in December 2020.

Argentina recalls the arrival of an Argentine tourist in December 2021, who entered the town of Jesús María with the new coronavirus in Cordoba, from Dubai, United Arab Emirates. After having had several family gatherings, she infected 8 people with COVID positive from her environment and 78 were isolated.

“Until we achieve a high vaccination rate in all countries, we will continue to run the risk of an increase in infections, with the possibility of new variants that can avoid vaccines,” Tedros warned. Statistics from national health networks indicate that 64 per cent of the world's population (almost two thirds) has received at least one dose of the 11 billion vaccines administered on the planet, although that percentage drops to 14 per cent in low-income countries. “The pandemic is not over. We are still going to see cases of the spread of this virus and we must continue to be vigilant. We need to continue to be careful,” said Dr. Ashish Jha, White House health coordinator.

Jha indicated that she is not aware of anyone having become seriously ill after the Gridiron dinner in Washington. “As long as people are vaccinated and boosted, we now have many treatments available, let's put that together, and the good news is that so far no one has been particularly ill. And that's what we need to be tracking, making sure that when there are outbreaks, we can take care of people.”

Some infectious disease experts argue that, despite increased access to vaccines and tests, covid-19 super-spread events are not over. “I think this event in Washington was similar to a superpropagation event. It was clearly an event where people gathered, and the virus attended and made itself known to many infected people and people,” Schaffner said, insisting that COVID-19 super-spread events are not “a thing of the past.”

“So, do they still happen? Of course. How important are they? Well, they knocked out a good number of people for a while, at least having to isolate themselves at home because they were infected. While I don't think superpropagation events will cause sudden increases in hospitalizations, they can continue to increase and accelerate transmission of the virus, causing milder disease in our communities,” Schaffner concluded.

As we transition to living with COVID-19 in the long term, we will be more likely to encounter someone with a mild, but still communicable infection, through everyday activities such as going to school, the office, a party, church, a sporting or recreational event, etc. there is a better chance of identifying them. “We are now much more likely to find people who are positive but asymptomatic than we were two years ago,” said Dr. Georges Benjamin, executive director of the American Public Health Association.

The concept of a superpropagation event is “not new,” said Keri Althoff, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, who believes that the United States is at a point where COVID-19 superspread events are becoming a thing of the past as coronavirus circulates widely in our communities. Events that result in more infections than otherwise would not have occurred can be better described as outbreaks, Althoff said, similar to how we see outbreaks of other vaccine-preventable respiratory diseases such as measles or influenza.

Very early in the pandemic, when the number of cases was low, we saw and investigated superpropagation events, and those investigations provided important information about the virus when we knew very little. Large-scale outbreaks continue to provide information on how this variant is interacting with a population that has a much higher level of population immunity now than we had at the beginning of the pandemic,” said the expert.

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