According to a new study, a partygoer at last year’s Mardi Gras could have been the catalyst for 50,000 cases of coronavirus.
It is known that the celebration of the 2020 carnival in Louisiana at the end of February made the state one of the first hot spots of the US pandemic.
But researchers now believe that only one person brought the virus to the city in the weeks leading up to Shrove Tuesday and caused tens of thousands of infections due to people crowding together and sharing food and drink without masks.
I suspect that Mardi Gras’ “Zero Patient” infected 800 people in the two weeks between February 13 and the end of the Ash Wednesday festivities on February 26.
And the 800 then continued to spread the infection to another 50,000 people in Louisiana and neighboring states.
The team – made up of several institutions, including the Scripps Research Institute, Tulane University and Louisiana Health Shreveport State University – says the outbreak remained largely undetected due to a lack of testing and mitigation efforts at the time.
A new study has found that only one person, probably traveling from Texas, brought COVID-19 to New Orleans for Carnival 2020. Pictured: Risk of the virus spreading in the US in the first week after Mardi Gras
As of Mardi Gras and Ash Wednesday, nearly 800 people were likely infected and led to 50,000 cases in the first wave in Louisiana. Pictured: 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 a cruise ship in which an outbreak came from a single source. Pictured: Bourbon Street in New Orleans on Mardi Gras Day in February 2020
Studies later showed that COVID-19 exposure rates approached 10% in the first wave in Louisiana between March 9 and May 15. Pictured: Saint Anne’s Society parade during New Orleans Mardi Gras, February 2020
– At that time, there were no precautions. No one thought about it, “study co-author Mark Zeller, a Scripps researcher, told DailyMail.com.
“Nobody wore masks, nobody distanced themselves socially, just spending like the previous year.
But the problem was that the virus was already there. The virus was most likely introduced before Mardi Gras and has just begun and dramatically increased its transmission like a snowball.
For the study, which has not yet been evaluated by colleagues and published on the pre-print server medRxiv.org, the team sequenced the genomes of the virus in New Orleans and other locations in Louisiana during the first wave, March 9 – 15 May .
These were then compared with genomes in the US and globally to identify the occurrence 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 a cruise ship in which an outbreak came from a single source.
The infections have spread to other states, such as Texas, Mississippi and Alabama, but orders 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,” Zeller said.
“Obviously, the size of Mardi Gras is much, much bigger, but it was a very common event, which happens practically like a cruise ship.
“You have an infected person coming in and the virus starts jumping on the ship. Think of Louisiana as a big ship, where the virus came in and was just dramatically amplified by Mardi Gras.
They also looked at mobility data to gather who was traveling to and from New Orleans during the carnival.
Between February 14, 2020, the beginning of the holiday, and February 25, Mardi Gras Day, several Americans visited the city.
The first case of COVID-19 in Louisiana was reported on March 9. Unlike early outbreaks in New York and Washington, the researchers determined that Patient Zero was not from Europe or Asia, but from someone traveling domestically.
An analysis found that the sick person was probably from Texas, which was more than twice as likely as the next most likely source.
This is because in February 2020, Texas passengers accounted for 13% of travel to New Orleans and 35% to Shreveport, a city in northwest Louisiana.
About 800 people were infected the next day, Ash Wednesday, which continued to spread the virus to others and lead to about 50,000 confirmed cases, mostly in Louisiana during the first wave in the next few months.
“The rapid nature of the early COVID-19 epidemic in New Orleans has likely led to thousands of additional cases, which are supported by seroprevalence studies showing exposure rates of nearly 10% by May 15, 2020 in New Orleans,” they wrote. the authors.
‘Compared to neighboring states that did not experience the same explosive waves as Louisiana, the CDC … estimated that the seroprevalence in Louisiana was 35% to 134% higher than in other southern US states.
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 residence orders have emerged to help spread the virus to other states.
This year, New Orleans closes its bars from February 12 to February 17 and no unit will be allowed to sell alcoholic beverages. Pictured: A group of partygoers on a balcony throw the beads of the crowd below on Bourbon Street on Mardi Gras Day in February 2020
It was kind of a perfect storm. Very few people in the United States were aware of the epidemic about to become so everyone is still behaving normally, Zeller said.
“If Mardi Gras had come three weeks before, the virus would not have been there or the amplification would have been much smaller.
“It simply came to our notice then another far away, so if Mardi Gras was a month later, it’ssomeone would have been aware of the virus and it would have been canceled, it was just the unfortunate moment of the event. ‘
This year, Mardi Gras and Carnival will look very different.
The bars will be closed from February 12 to February 17 and no unit, such as restaurants, will be allowed to sell alcoholic beverages.
Pedestrians and vehicles will not be allowed on some of the city’s most popular streets between 19:00 and 03:00 and there will be no parking areas in place.
Indoor gatherings will be limited to a maximum of 10 people and outdoor gatherings to a maximum of 25 guests.
“Vaccinations are on the rise, but only a very small percentage of the population is vaccinated at this time,” Zeller said.
“It simply came to our notice then. As soon as we stop wearing face masks, we stop social distancing, the virus will return and spread again.
“People shouldn’t have parties … I know everyone is fed up with the whole situation, but it’s not the right time to start the party.”