Did this apple sauce really test positive for Covid-19? Wait, that’s not the full story

This apple sauce made by the brand Favorit was tested for Covid-19 with an antigen test made by manufacturer MEDsan.
This apple sauce made by the brand Favorit was tested for Covid-19 with an antigen test made by manufacturer MEDsan. © Facebook
Text by: Liselotte Mas
9 min

A video claiming to show that antigen tests aren’t an effective way of detecting Covid-19 has been circulating online since early December. The video shows the test being carried out on a container of apple sauce, which tests positive. From this video, a number of social media users concluded that the test wasn’t reliable and, thus, that the number of cases of Covid-19 had been exaggerated. But these people jumped to this conclusion a bit too quick. Turns out, this test was made to be used on humans, not foods – hence the wonky result.

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The video, which runs to 2 minutes 15 seconds, has garnered hundreds of thousands of views on Facebook, Twitter, Telegram and Instagram since it first started circulating on December 8. The social media users sharing it claim that the video shows a container of apple sauce testing positive for Covid-19 using a RT-PCR test [Editor’s note: the most effective test] as well as a newly developed antigen test, which gives quicker results but which French authorities have concluded is less effective.

"This apple sauce tested positive during the test,” reads this comment left on Facebook on December 8. This is the oldest instance of the video online that our team was able to find. It garnered more than 200,000 views. 

Did the apple sauce really test positive?

If you look closely at the video, then you’ll see that it is made up of several different shots edited together. 

The first shot shows a person wearing gloves using a test made by MEDSan, which is the name of a German start-up that manufactures different tests. The MEDSan website lists a variety of tests including the antigen test used for this experiment. 

The way that this test works is explained in a variety of languages and a video on the MEDSan site. Essentially, the sample being evaluated is diluted in a liquid and then placed on a swab. Whether the substances has tested positive or negative is expressed by different coloured bands. 

The documents on the website explain that if the substance is positive, you’ll see two bands appear (the C band and the T band). Lots of social media users who had read this guide pointed out that, in the first shot in the video, only the C band appears, which they say indicates a negative result. 

Twitter user @YoughsD posted this response to the video. The tweet says (in French): “This isn’t a PCR test, it’s a genetic test (it’s written below) and it is negative. You’re welcome.”
Twitter user @YoughsD posted this response to the video. The tweet says (in French): “This isn’t a PCR test, it’s a genetic test (it’s written below) and it is negative. You’re welcome.” © Twitter

Other social media users commented that there seemed to be a very faint line next to the T band, which could mean that the test was actually positive, as the MEDSan site did say a weak or faint line should be interpreted as a positive result. 

These screengrabs show the end of the video, where you can see a very faint line next to the letter T. We circled it in pink for emphasis.
These screengrabs show the end of the video, where you can see a very faint line next to the letter T. We circled it in pink for emphasis. © Facebook

This very light second line isn’t visible in the first shot in the video, only in the second video sequence and then a photo that appears at the end. The same test model appears in each sequence but it is possible that the test was replaced by another for the later shots. However, we can’t prove this for certain. 

Our team contacted MEDSan, which confirmed that the two lines, including the faint one at the T band, did indeed indicate a positive result for Covid-19. 

In this image provided by the manufacturer, you can see what a positive result looks like on their rapid antigen test for Covid-19.
In this image provided by the manufacturer, you can see what a positive result looks like on their rapid antigen test for Covid-19. © MEDsan GmbH Germany

In the photo below, which was shared with our team by the manufacturer, you can see a variety of positive results. The lines appear with varying degrees of intensity but all are positive. The two results towards the bottom show roughly what you see on the test at the end of the video. 

Does this test indicate that the apple sauce is infected with Covid-19?

Antigen tests were developed and manufactured to detect the virus in humans using samples taken from a nasal or sometimes oral swab. They weren’t designed to absorb other substances, which can affect the testing process, resulting in a false positive or false negative.  

Our fellow fact-checkers at AFP Factuel contacted the manufacturer MEDSan, who carried out a series of tests using other “non-pertinent” materials, including cherry jam, an alcohol-based disinfectant, apples, apple juice and window cleaner. The cherry jam and disinfectant yielded positive results when tested.  

This images shows the results of a Covid-19 antigen test used on a variety of materials by its manufacturer MEDsan. This photo was shared with the AFP on December 9, 2020.
This images shows the results of a Covid-19 antigen test used on a variety of materials by its manufacturer MEDsan. This photo was shared with the AFP on December 9, 2020. © MEDSan Gmbh Germany/AFP

AFP interviewed two researchers who said that there are a few explanations for these results, including the level of acidity. The PH of the sample is usually neutralised in a solution that comes with the test. However, according to Annette Beck-Sickinger, a professor of biochemistry, this solution isn’t calibrated "to neutralise very acidic foods like apple or mango”. 

Professor Thomas Decker said it is impossible to tell how effective a test would be on humans by testing it on a food: "The test was designed to combine antibodies and antigens in specific conditions, conditions which are disrupted by the presence of food. It’s as if we filled a car’s petrol tank with gas and expected it to move forward.” 

It’s impossible to say if the apple sauce contains Covid-19

In conclusion, it’s impossible to know from this video if the apple sauce in the video really contained traces of the virus or if the test was disrupted by the level of acidity or sugar in the apple sauce or some other factor. That said, according to several specialists quoted by the AFP, it’s impossible to get a reliable result when you are using this test developed to test for the presence of the virus in the human body on a food. This also means that an experiment using food provides information about the reliability of this test on a human. 

Hasty conclusions used to advance political agendas 

There was likely a political agenda behind the widespread sharing of this video. The video uses catchy music, text and graphics. It’s also in German, which gives us a good guess as to its origins. 

Faced with a sharp increase in the number of cases and deaths during the second wave of the pandemic, the German government decided in late November to extend restrictions and make them tougher on December 13. This decision was extremely unpopular among some groups, who have cast doubt on the reliability of these numbers and, thus, the tests. 

The far-right movement AfD (Alternative for Germany) is leading the campaign against the vaccine and other health measures, including social distancing. One youth group within the party posted a meme [Editor’s note: a funny photo montage often with text] making fun of “rapid tests” along with an image of apple sauce. 

In this tweet, the AfD youth group uses the image of a glass of Coca-Cola, used in a similar experiment by a far-right Austrian parliamentarian.
In this tweet, the AfD youth group uses the image of a glass of Coca-Cola, used in a similar experiment by a far-right Austrian parliamentarian. © Twitter

The video was widely shared on Telegram, an encrypted messaging service. These channels, like "NRW News" and "Wake up", share pro-Trump, anti-vaccine and conspiracy-filled theories in German to hundreds of followers.  

Michael Schnedlitz, an Austrian member of parliament from the far-right FPÖ movement, performed a similar demonstration using an antigen test on Coca-Cola, yielding a positive result. Schnedlitz claimed that these tests were useless and the government had put in place a type of “light dictatorship” during the Covid-19 pandemic.

The member of parliament is holding a rapid test made by manufacturer Dialab.
The member of parliament is holding a rapid test made by manufacturer Dialab. © Facebook

The manufacturer of the test in question, Dialab, said that Schnedlitz hadn’t followed proper procedure. To emphasise their point, they posted a video on Facebook showing that the result should be negative if the test was carried out properly.  

In the caption on this video, the manufacturer explains that Schnedlitz didn’t dilute the Coca-Cola with the special solution used to neutralise its high level of acidity. The acidity “destroyed the anticorps proteins in the test”, leading to a positive result. According to the manufacturer, any other similar test made by another manufacturer would have also given a false positive under these circumstances. In their own counter-experiment, an employee of the manufacturer mixed the fizzy drink with the neutralising solution and got a negative result.

“These tests should always be carried out by hospital staff or people trained to administer them in order to avoid this kind of results or presentations,” the manufacturer said.