Where did Covid-19 ACTUALLY start? Origins story gets murkier after Italian boy, 4, infected in November 2019
According to the researchers, the findings, in agreement with other evidence of early Covid-19 spread in Europe, 'advance the beginning of the outbreak to late autumn 2019'
The novel coronavirus that has killed over 1.5 million people globally was first identified in Wuhan, China, in December 2019. Experts are, however, still probing the origin of SARS-CoV-2, the virus that causes Covid-19. A new analysis now suggests that a four-year-old boy in Italy was infected with coronavirus as early as November 2019, about three months before the first case was identified in the country. This suggests that Covid-19 may have been spreading in Italy much before China confirmed the outbreak.
According to the researchers, the findings, in agreement with other evidence of early Covid-19 spread in Europe, “advance the beginning of the outbreak to late autumn 2019”. However, earlier strains also might have been occasionally imported to Italy and other countries in Europe during this period, “manifesting with sporadic cases or small self-limiting clusters,” they argue. “These importations could have been different from the strain that became widespread in Italy during the first months of 2020,” writes the team from the Department of Biomedical Sciences for Health, University of Milan, Italy. The findings have been published in the Emerging Infectious Diseases journal of the US Centers for Disease Control and Prevention (CDC).
The country office of the World Health Organization (WHO) in China picked up a media statement by the Wuhan Municipal Health Commission from their website on cases of “viral pneumonia” in Wuhan in December 2019. On January 9, WHO reported that Chinese authorities have determined that the outbreak is caused by a novel coronavirus.
Official records indicate that Italy’s first two coronavirus cases were recorded on January 30, 2020, when two tourists from China tested positive for SARS-CoV-2 in Rome. Italy’s first domestic coronavirus case was detected in late February 2020 in Lombardy. The 38-year-old man had no history of possible contacts with positive cases in Italy or abroad. “The first known Covid-19 case in Italy was reported in the town of Codogno in the Lombardy region on February 21, 2020. However, some evidence suggests that SARS-CoV-2 had been circulating unnoticed for several weeks in Lombardy before the first official detection,” say investigators.
What did the researchers find?
As participants in Italy’s Measles and Rubella Network, a sensitive case-based surveillance system, the team observed in Milan during late autumn 2019 cases of suspected measles in patients who eventually tested negative for measles. “We, therefore, retrospectively explored a possible etiologic involvement of SARS-CoV-2 in these non-measles-linked rash cases,” they explain.
The investigators analyzed swabs specimens collected during September 2019-February 2020 from 39 consenting patients. The coronavirus was identified in a specimen collected from a 4-year-old boy who lived in the surrounding area of Milan and had no reported travel history.
On November 21, 2019, the child had a cough and rhinitis. About a week later on November 30, he was taken to the emergency department with respiratory symptoms and vomiting. On December 1, he had an onset of a measles-like rash. “On December 5 (14 days after symptom onset), the oropharyngeal (throat) swab specimen was obtained for clinical diagnosis of suspected measles,” the findings state.
The swab specimen, which was collected for measles diagnosis, was “not optimal” for SARS-CoV-2 detection because it was taken from the boy’s throat rather than his nose, and it was collected 14 days after the onset of symptoms, when viral shedding is reduced, argue scientists. But the specimen was confirmed as Covid-19 positive by “repeated amplification and sequencing.” “We identified severe acute respiratory syndrome coronavirus 2 RNA in an oropharyngeal swab specimen collected from a child with suspected measles,” notes the team.
According to researchers, the analysis is of epidemiologic importance because it expands the knowledge on timing and mapping of the SARS-CoV-2 transmission pathways. “Long-term, unrecognized spread of SARS-CoV-2 in northern Italy would help explain, at least in part, the devastating impact and rapid course of the first wave of Covid-19 in Lombardy. Full exploitation of existing virologic surveillance systems to promptly identify emerging pathogens is, therefore, a priority to more precisely clarify the course of outbreaks in a population,” write authors. They add, “Further studies aimed at detecting SARS-CoV-2 RNA in archived samples suitable for whole-genome sequencing will be crucial at determining exactly the timeline of the Covid-19 epidemic in Italy and will be helpful for the preparedness against future epidemics.”
This is not the first study to suggest that Covid-19 may have been circulating in Italy earlier than previously thought. In November 2020, Italian researchers revealed that 11,6% of 959 healthy volunteers enrolled in a lung cancer screening trial between September 2019 and March 2020, had developed coronavirus antibodies well before February. A further SARS-CoV-2 antibodies test was carried out, which indicated that four cases dated back to the first week of October 2019 were also positive for SARS-CoV-2 antibodies, suggesting they had got infected in September 2019.
The authors emphasized that finding SARS-CoV-2 antibodies in asymptomatic people before the Covid-19 outbreak in Italy may “reshape the history of the pandemic.” However, they argued that the report did not dispute the origins of coronavirus. “These findings simply document that the epidemic in China was not detected in time,” Giovanni Apolone, co-author and scientific director of the National Cancer Institute (INT), Milan, concluded.