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© Reuters. File photo: In this illustration taken on November 9, 2020, the word “COVID-19” is reflected on a drop on the needle of a syringe. REUTERS/Dado Ruvic/Illustration
Emilio Parodi
Milan (Reuters)-A controversy over blood testing has raised questions about a study in Italy that showed that the coronavirus spread outside China much earlier than expected, highlighting attempts to determine what the virus is. Challenges that arise from time to time.
A study published by Italian scientists last year showed that in a lung cancer screening test in October 2019, neutralizing antibodies against the SARS-CoV-2 coronavirus were found in the blood of healthy volunteers in the country.
COVID-19 was first detected in the central Chinese city of Wuhan in December 2019, and the first patient in Italy was found in a small town near Milan on February 21 last year.
Where, when and how the virus originated is one of the core mysteries of COVID-19, which has caused more than 4 million deaths.
On Thursday, China rejected the World Health Organization’s (WHO) plan to conduct a second phase of the origin investigation, which included the hypothesis that it might escape from the Chinese laboratory. In May, US President Joe Biden ordered his assistants to find answers to the origins.
Italian scientists from the VisMederi laboratory at the University of Siena and the Milan Cancer Institute (INT) said their research revealed detailed information about when the virus began to spread.
The results of their research released in November showed that 11.6% of the 959 healthy volunteers who participated in the cancer screening test between September 2019 and March 2020 showed signs that they had been infected with SARS-CoV-2, and most of them were infected with SARS-CoV-2. Most are as early as February.
Most of the volunteers came from Lombardy, a northern region near Milan, which is the most severely affected area in Italy.
The antibody test used is designed in-house.
At the request of the World Health Organization, the researchers retested the samples earlier this year and asked Erasmus University Rotterdam to help with the review.
Scientists have now submitted the new findings titled “Italian SARS-CoV-2 Spread Timeline: Results of Independent Serological Retests” to the website bioRxiv, a free online archive of unpublished clinical studies, before peer review .
They said these confirmed their initial conclusions.
But their Dutch counterparts said the results are not conclusive and they have not signed the latest research.
“Based on the criteria we set, we were unable to confirm most positive results. Therefore, we came to a different conclusion,” said Marion Koopmans of Erasmus University. Earlier this year, she was one of the virologists who visited China for COVID-19.
paper
The difference in results is concentrated on the test standard.
The focus of the re-examination of the two laboratories is on the 29 biological samples that Italian researchers tested positive between October and December 2019, and the 29 samples they tested were negative and 29 samples during the same period. Review. 2018 is also negative.
The samples are sent blindly, which means that the scientist does not know which samples are which.
The Italian research focuses on identifying the coronavirus-related antibody IgM (immunoglobulin-M), which indicates a recent infection.
Of the 87 samples reviewed, both laboratories found that three samples were positive for IgM. The first time can be traced back to October 10, 2019, in Lombardy.
But the Erasmus standard requires the identification of all three coronavirus-related antibodies-IgM, neutralizing antibody and IgG, and none of the samples meet this requirement.
The other samples had the IgM levels identified by VisMederi, but were below the threshold set by Erasmus. The oldest one dates back to September 3, 2019, from the Veneto region.
At the same time, INT researchers are preparing a new paper on 25 studies conducted in Europe and North America at the beginning of the pandemic.
According to Giovanni Apolone, INT’s scientific director, 23 of these studies have reached similar conclusions to the Italian study.
Last month, a study by the University of Kent in southern England found the first case of COVID-19 in China in October 2019.
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