No, this photo is not evidence of a new, deadly mosquito in France

Social media users in France have been sharing a photo of an infected bug bite along with a caption explaining that a new mosquito bite can cause deadly infections. However, this photo is from 2017 and the girl in the pic was probably not  in real danger.
Social media users in France have been sharing a photo of an infected bug bite along with a caption explaining that a new mosquito bite can cause deadly infections. However, this photo is from 2017 and the girl in the pic was probably not in real danger. © Observers

In recent days, French social media users have been widely sharing a photo showing a nasty bug bite on someone’s inflamed, red knee. The caption claims that the swollen knee belongs to a young woman named Deanna, who was bitten the night before by a new type of mosquito and that she is at risk of dying from the infection. Turns out, however, this photo is from back in 2017 and no one thought the bite could be deadly. 


The photo has been circulating on Facebook for the past couple of weeks and has been shared several thousand times, always with the same caption. One post was shared half a million times. The image shows a person’s knee, with the inflamed area outlined in black marker. 

The caption claims that the young woman in the photo is named Deanna and she went to the emergency room the day after getting bit by a new type of mosquito, which caused a life-threatening infection. 

The caption, in French, contains a terrifying detail: "If they had waited any longer, the infection would have gotten into her blood and caused her death…” (sic). The caption also included calls to action like "Take three seconds to share this, you might save a life…”  and "Urgent, circulate widely".

A bite from 2017 and in the United States, not France 

But contrary to these captions and comments, this isn’t a recent photo, says the fact-checking team at 20 Minutes. We checked ourselves by running the photo through a reverse image search (click here to find out how). We immediately pulled up a Facebook post in English as well as an article published in the United States back in 2017 that includes the same swollen knee picture. The captions tell the same story as the French publications. 

When we searched for the photo on Facebook, we pulled up the original post featuring this photo. On March 16, 2017, an American mum named Sonia Giudenian took to Facebook to warn her friends about what had happened to her daughter after she got bit by a mosquito. Her post tells the same story as the French posts, except for one important detail…  while the swollen knee may look unpleasant, Sonia doesn’t say anything about the infection becoming deadly if it spreads to her daughter’s blood.

"So I took her into the ER where we found out that there is a new kind of mosquito bite that causes an infection. If we waited any longer it would have been in her blood," Giudenian wrote in her post.

Giudenian’s post from four years ago – albeit less sensationalised than the recent posts – was still shared more than three million times. Her aim was to warn other families about the risks so that, if they saw a mosquito bite getting red or inflamed, they would take it seriously. In the comments section, she says that her daughter was doing well after about 10 days of antibiotics. 

'There are currently no new potentially deadly, mosquito-borne infections in France or, indeed, Europe'

To get more information, we showed the photo and post to Professor Olivier Bouchaud, the head of infectious diseases at the Avicenne Hospital in Bobigny, a suburb of Paris. Bouchard says that, currently, there are no new potentially deadly, mosquito-borne infections in France. He also added that there were no new types of mosquitos or insects posing a threat or, indeed, no new methods of biting or transmitting an illness emerging.

Bouchaud said it was hard to come to a conclusion about what specific infection had afflicted Giudenian’s daughter without additional information or context about the bite. He said if the symptoms remained localised, then there should be no risk of the infection becoming "deadly".

It could be Lyme disease. It could also be a bite from any insect, including a spider, that might trigger an allergic reaction and extensive swelling. It could also be inflammation within the cellulite caused by a common infection called streptococcus. It could also be various other types of inflammation.

The photo seems to show a very localised problem. As a general rule, you should get worried if someone develops a high fever after getting bitten, especially if they also have other symptoms. It’s especially worrying if these symptoms are neurological, like facial paralysis or paralysis of a nerve... or more general neurological symptoms like losing consciousness. When someone has a high fever and shows signs of getting tired or sleepy, slowing down, having trouble processing or paying attention, that could be encephalitis, or brain swelling. But it is extremely, extremely rare for a mosquito bite in France to cause brain swelling.