A new study says the coronavirus was in Milan as early as November 2019

A new study says the coronavirus was in Milan as early as November 2019

A study by the University of Milan retested a swab of a 4-year-old boy hospitalized at the end of November 2019 with symptoms attributable to the coronavirus. The swab today tested positive for Sars-Cov-2. What does it mean and possible doubts

(image: Getty Images) The first case of coronavirus in Italy would date back to the second half of November 2019, exactly three months before the official cases traced in the Lodi area in February 2020 (here are some key milestones of the pandemic). This is shown by a study conducted by the State University of Milan that documents the case of a 4-year-old child with a positive swab for the new coronavirus already in the second half of November 2019. At the time, a swab in the throat was requested for a suspicion of measles, given that the child had various symptoms attributable to this disease, including skin rash and blisters. But today his sample, analyzed again, indicates a positivity to Sars-Cov-2. Although false positives are still possible, the result provides a first indication of the possibility that Covid-19 was present in Italy (and probably not only here) at the end of autumn 2019. The results are published in Emerging Infectious Diseases.

Measles or Covid-19?

The boy had started having symptoms, including cough and cold, on November 21, 2019. But the ailments had gotten worse and on 30 November 2019 the child, with breathing difficulties and widespread vomiting, was taken to the emergency room. Hospitalized, he developed a skin rash with diffuse blistering on December 1, similar to that seen in measles. For this reason, on December 5, 2 weeks after the appearance of the first symptom, he underwent an oropharyngeal swab to check for the presence of the exanthematous disease. The swab was negative for the virus responsible for measles.

Today, in light of the Covid-19 pandemic, his sample has been re-analyzed and the second exam in the case of this child is not the result of a random choice. There is evidence that especially in children skin manifestations similar to those of chicken pox or measles, as well as in some cases Kawasaki syndrome - which has elements in common with Covid-19 but is not caused by the coronavirus.

“The idea - explains Silvia Bianchi, co-author of the study - was to retrospectively investigate all cases of exanthematous diseases identified in Milan, by the measles and rubella surveillance network. The period considered is the one that goes from September 2019 to February 2020 and the samples are those that tested negative in laboratory investigations for the confirmation of measles ". The study was carried out in the subnational laboratory, WHO accredited, for the surveillance of measles and rubella (MoRoNet) and in the research center EpiSoMi - Epidemiology and molecular surveillance of infections.

The result

In the research, the experts analyzed 39 samples taken from children with unidentified infectious forms, of which in one case, that of the 4-year-old child with symptoms from 21 November, who tested positive for Sars-Cov-2. The buffer used is the Rt-Pcr molecular one, the classic one. The test was repeated. The child had not traveled recently and had not been to China. Despite the absence of travel, the result is not unreasonable, also because some studies had indicated that at the time the virus was already circulating in China and perhaps not only here.

Some doubts

Another very recent study, conducted by the National Cancer Institute of Milan, in collaboration with the University of Milan, had indicated the potential presence of the coronavirus in the city as early as September 2019. But the research has raised doubts and received some objections. The perplexities arose from the fact that the researchers had identified the presence of antibodies against the virus (and not the viral RNA), which in some cases may also be associated with other coronaviruses. In this case, the authors specify, the swab has traced the rna, the structure of the virus and, although false positives are possible also in this case, the data is certainly more reliable than that obtained with antibodies.

Reconstructing the stages of the virus is essential

“The result expands our knowledge on the timing and mapping of the transmission paths of the new coronavirus,” the study reads. "We described the first evidence of the presence of the SARS-Cov-2 rna in an Italian patient, about three months before the first case reported in Italy". The hypothesis that the virus circulated in Lombardy long before could explain at least in part the strong impact of the epidemic in this region.

The idea is that deepening the subject will be essential to better understand the roots of the spread of the virus, of which we still know little. Where did the infection start and when? How did the infection spread? How long has the virus been around without being detected and where? These are all questions to which we still don't have precise answers. In this sense, the various surveillance systems - in this case it was the measles and rubella monitoring network - can do a very important job in reconstructing the stages of the virus. Refine the tools and carry out this work, the authors underline, could be useful both in the unfortunate occasion of the Covid-19 pandemic but also to study and detect future epidemics ever more promptly.

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