A reveler at last year’s Mardi Gras celebration may have been the catalyst for 50,000 cases of coronavirus, says a new study.
It is well known that the 2020 Carnival celebration in Louisiana in late February made the state one of the first pandemic spots in the United States.
But researchers now believe that a single person probably brought the virus to town in the weeks before Fat Tuesday and generated tens of thousands of infections due to people crowding and sharing food and drinks without masks.
They suspect that Mardi Gras ‘Patient Zero’ infected 800 people in the two weeks between February 13 and the end of the festivities on Ash Wednesday, February 26.
And those 800 then spread the infection to another 50,000 people in Louisiana and neighboring states.
The team – which consisted of several institutions, including the Scripps Research Institute, Tulane University and Louisiana State University Health Shreveport – says the outbreak went largely unnoticed due to the lack of testing and mitigation efforts at the time.
A new study determined that a single person, probably traveling from Texas, brought COVID-19 to New Orleans for Carnival 2020. Photographed: The risk of spreading the virus in the US in the first week after Mardi Gras
At Mardi Gras and Ash Wednesday, nearly 800 people were probably infected, which led to 50,000 cases in Louisiana’s first wave. In the photo: percentage of people who traveled from other states to New Orleans before Mardi Gras 2020
There was little genetic variety in the samples found in New Orleans, which created conditions similar to those of a cruise ship in which an outbreak comes from a single source. Pictured: Bourbon Street in New Orleans on Mardi Gras Day in February 2020
Further studies showed that exposure rates to COVID-19 were close to 10% in Louisiana’s first wave from March 9 to May 15. Photo: Saint Anne Society Parade during Mardi Gras in New Orleans, February 2020
‘At that time, there were no precautions. Nobody was thinking about it, ‘study co-author Mark Zeller, a researcher at Scripps, told DailyMail.com.
‘Nobody wore a mask, nobody distanced themselves socially, just partying like the year before.
“But the problem is that the virus was already there. The virus was probably introduced before Mardi Gras and just started, and drastically increased transmission like a snowball. ‘
For the study, which has not yet been peer-reviewed and published on the prepress server medRxiv.org, the team sequenced genomes of the New Orleans virus and elsewhere in Louisiana during the first wave, from March 9 to March 15. May .
Then, they were compared with the genomes of the USA and globally to identify the emergence of COVID-19 in the state of Bayou.
There was little genetic variety in the sample found in New Orleans, which created conditions similar to that of a cruise ship in which an outbreak comes from a single source.
Infections have spread to other states, such as Texas, Mississippi and Alabama, but requests to stay at home have prevented the virus from spreading much further (above)
“I think there are a lot of people in a relatively small space, it’s a fair comparison,” said Zeller.
‘Obviously, the scale of Mardi Gras is much, much bigger, but it was an oversizing event, which basically happens like a cruise ship.
– You have an infected person arriving and the virus starts to spread through the ship. Think of Louisiana as a big ship, where the virus entered and was dramatically amplified by Mardi Gras
They also analyzed mobility data to collect who was traveling in and out of New Orleans during Carnival.
Between February 14, 2020, the beginning of the celebration, and February 25, Mardi Gras Day, more than one American was in the city.
The first COVID-19 case in Louisiana was reported on March 9. Unlike the first outbreaks in New York and Washington, the researchers determined that Patient Zero was not from Europe or Asia, but from someone traveling to the country.
An analysis determined that the sick person probably came from Texas, which was twice as likely as the next state most likely to be the source.
That’s because during February 2020, Texas passengers were responsible for 13% of trips to New Orleans and 35% of trips to Shreveport, a city in northwest Louisiana.
Approximately 800 people were infected the next day, Ash Wednesday, which started to spread the virus to other people and lead to about 50,000 confirmed cases, mainly in Louisiana, during the first wave in the following months.
“The rapid nature of the initial COVID-19 epidemic in New Orleans has probably resulted in thousands of additional cases, which is corroborated by seroprevalence studies showing exposure rates of almost ten percent through May 15, 2020 in New Orleans,” the authors wrote.
‘In comparison with neighboring states that did not experience the same first explosive waves as Louisiana, the CDC … estimated that seroprevalence in Louisiana was 35 to 134% higher than in other southern states in the US ‘
And while the New Orleans strain has led to infections in other parts of Louisiana and other southern states, including Texas, Mississippi and Alabama, home stay orders appear to help the virus spread to other states.
This year, New Orleans is closing bars from February 12-17, and no establishment will be allowed to sell alcoholic beverages for travel. In the photo: a group of revelers on a porch throw beads to the crowd on Bourbon Street on Mardi Gras day in February 2020
‘It was kind of a perfect storm. Very few people in the USA were aware of the epidemic that was becoming so strong“Everyone was still behaving normally,” said Zeller.
“If Mardi Gras had happened three weeks earlier, the virus would not have been there or the amplification would have been much less.
‘It also works another distance around, so if Mardi Gras was a month later, andEveryone would know about the virus and it would have been canceled. It was just an unfortunate moment of the event.
This year, Mardi Gras and Carnival will be very different.
The bars will be closed from 12 to 17 February and no establishment, like restaurants, will be able to sell alcoholic drinks for travel.
Pedestrians and vehicles will not be allowed to pass through some of the city’s busiest streets from 7 pm to 3 am and there will also be no parking areas in place.
Indoor meetings are limited to a maximum of 10 people and outdoor meetings to a maximum of 25 guests.
“Vaccines are increasing, but only a small percentage of the population is vaccinated now,” said Zeller.
“We must still behave for a few months. As soon as we stop wearing face masks, stop social distancing, the virus will reappear and spread again.
‘People shouldn’t have parties … I know everyone is sick of the whole situation, but it’s not the right time to start celebrating.’