https://www.sciencedirect.com/science/article/pii/S0013935122013068
Many of you may recall a study from over two years ago which found traces of covid RNA in sewage water in Lombardy, Italy.
This is not that study. This is a study released this month which confirms those earlier findings. A new strain which predates the Wuhan alpha strain was sequenced, labeled proCoV2.
Abstract
As a reference laboratory for measles and rubella surveillance in Lombardy, we evaluated the association between SARS-CoV-2 infection and measles-like syndromes, providing preliminary evidence for undetected early circulation of SARS-CoV-2. Overall, 435 samples from 156 cases were investigated.
RNA from oropharyngeal swabs (N = 148) and urine (N = 141) was screened with four hemi-nested PCRs and molecular evidence for SARS-CoV-2 infection was found in 13 subjects. Two of the positive patients were from the pandemic period (2/12, 16.7%, March 2020–March 2021) and 11 were from the pre-pandemic period (11/44, 25%, August 2019–February 2020).
Sera (N = 146) were tested for anti-SARS-CoV-2 IgG, IgM, and IgA antibodies. Five of the RNA-positive individuals also had detectable anti-SARS-CoV-2 antibodies. No strong evidence of infection was found in samples collected between August 2018 and July 2019 from 100 patients. The earliest sample with evidence of SARS-CoV-2 RNA was from September 12, 2019, and the positive patient was also positive for anti-SARS-CoV-2 antibodies (IgG and IgM).
Mutations typical of B.1 strains previously reported to have emerged in January 2020 (C3037T, C14408T, and A23403G), were identified in samples collected as early as October 2019 in Lombardy. One of these mutations (C14408T) was also identified among sequences downloaded from public databases that were obtained by others from samples collected in Brazil in November 2019.
We conclude that a SARS-CoV-2 progenitor capable of producing a measles-like syndrome may have emerged in late June-late July 2019 and that viruses with mutations characterizing B.1 strain may have been spreading globally before the first Wuhan outbreak.
Our findings should be complemented by high-throughput sequencing to obtain additional sequence information. We highlight the importance of retrospective surveillance studies in understanding the early dynamics of COVID-19 spread and we encourage other groups to perform retrospective investigations to seek confirmatory proofs of early SARS-CoV-2 circulation.
The first detected covid samples were found in the US were from a flu study conducted in early 2020 in the Seattle area. In this case they just sent swabs to people with symptoms. They later retested the samples and found covid positive samples collected in late February, so it was almost certainly circulating before that, but anyone with covid would have assumed it was a flu or the worst cold of their lives.
Anecdotally, there was a lot of people reporting getting hit with a "cold from hell" in the Seattle area around that time.
We should have tested samples from any area in the world with higher than normal pneumonia rates in 2019, and there were several areas in the US where that was happening.