Researchers subsequently prove the pathogen in a man who was hospitalized on December 27. The case shows that the virus circulated in Europe a month earlier than previously thought.
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In the Paris Metro, passengers must wear a mask.
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French doctors, when analyzing frozen samples from the respiratory tract, found that they had already treated a man with Covid-19 in late December – a month before the country’s first official case became known. The result suggests that the new corona virus circulated in Europe earlier than previously thought.
The investigation was published in the Journal of Antimicrobial Agents. The World Health Organization (WHO) described the result on Tuesday as “not surprising”. At the same time, however, the authority has encouraged other countries to look for previously unknown cases in their hospital archives. This could give a clearer picture of the outbreak.
For their study, the researchers, led by Yves Cohen from the Groupe Hospitalier Paris Seine-Saint-Denis, tested the archived laboratory samples on Sars-CoV-2, the causative agent of Covid-19, in 14 patients. The patients were all hospitalized in December and January for severe pneumonia. A pathogen could not be detected in them. At that time, however, Sars-CoV-2 could not be tested.
Where the man got infected is not known
The doctors have now made up for this. In a patient who survived the disease, the ex-post test, verified using various methods, gave a positive result. It is a 42-year-old man who was born in Algeria but has long lived in France. The fishmonger had come to hospital care on December 27, four days earlier the symptoms of fever, cough and headache had started.
The man tested positive apparently infected his two children, who also fell ill. However, his wife developed no symptoms. How the man got infected with the virus is unclear. Apparently he had never been to China himself. His last trip was to Algeria in August 2019. According to media reports, the infection could have been caused by his wife. Because at the time she was working in a supermarket on a sushi stand and was in contact with colleagues from China. It is unknown whether these people were previously in China.
According to experts, it is not clear whether the 42-year-old man is the first Covid 19 case in France. However, the study suggests that the virus may have spread undetected in some countries until it was first isolated from a patient. In Wuhan, for example, where the pandemic started, according to scientific estimates, the virus was already in circulation in November, long before the first patients with a mysterious lung disease were recognized in December. In Italy and the USA, too, there is much to suggest that Sars-CoV-2 arrived in the country weeks before the first official case.
Genetic evolution shows the way
The evolution of the pandemic can be traced using the genetic evolution of Sars-CoV-2. Researchers take advantage of the fact that the virus changes minimally over time in the host. The mutations thus created lead to slightly different virus strains which, like a royal ancestral gallery, have a clear relationship to one another. If you know the origin of the virus, the spread of the virus across the globe can be tracked in space and time.
The French study does not reveal the relationship between the coronavirus detected at the 42-year-old fishmonger and the thousands of Sars-CoV-2 isolates that have already been sequenced. But that would be important to know. This would show how the virus came to France.
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