[ad_1]
The researchers then test 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.
Passengers must wear a mask on the Paris metro.
French doctors, analyzing frozen samples from the respiratory tract, discovered that they had treated a man with Covid-19 in late December, a month before the country’s first official case was known. The result suggests that the new coronavirus was circulating in Europe earlier than previously thought.
The research was published in the Journal of Antimicrobial Agents. The World Health Organization (WHO) described the result Tuesday as “not surprising.” At the same time, however, the authority has encouraged other countries to also search 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 of the Groupe Hospitalier Paris Seine-Saint-Denis, analyzed laboratory samples on file at Sars-CoV-2, the causative agent of Covid-19, in 14 patients. All patients were 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.
It is unknown where the man became infected.
Doctors have now made up for it. In a patient who survived the disease, the ex post test, verified by various methods, gave a positive result. He is a 42-year-old man who was born in Algeria but has lived in France for a long time. The fishmonger came to hospital care on December 27, four days before, the symptoms of fever, cough and headache had begun.
The positive man apparently infected his two sons, who also became ill. However, his wife did not develop symptoms. It is unclear how the man became infected with the virus. Apparently he had never been to China. 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 at a sushi stand and was in contact with coworkers from China. It is unknown whether these people were previously in China.
According to experts, it is not clear if the 42-year-old man is the first case of Covid 19 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 began, the virus was already circulating, according to scientific estimates, in November, long before the first patients with a mysterious lung disease were recognized in December. Also in Italy and the United States 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. The 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 real ancestral gallery, have a clear relationship to each other. If you know the source of the virus, the spread of the virus around the world can be traced in space and time.
The French study does not reveal the relationship between the coronavirus detected by 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 got to France.
