Via medRxiv, a report that, if accurate, raises a whole lot of questions: SARS-CoV-2 in human sewage in Santa Catalina, Brazil, November 2019. The abstract:
We analysed human sewage located in Florianopolis (Santa Catalina, Brazil) from late October until the Brazil lockdown on early March. We detected SARS-CoV-2 in two samples collected independently on 27th November 2019 (5.49 ± 0.02 log genome copies/L). Subsequent samplings were positive until 4th March 2020 (coinciding with the first COVID-19 case reported in Santa Catalina), with a SARS-CoV-2 RNA increase of one log (6.68 ± 0.02 log genome copies/L). Our results show that SARS-CoV-2 has been circulating in Brazil since late November 2019, much earlier than the first reported case in the Americas (21st January 2020, USA).
I picked up this story from a report in the South China Morning Post, which also mentions a sewage test in Barcelona, Spain, in March 2019 which was positive for SARS-CoV-2. The medRxiv abstract of that report is here. It gets skeptical analysis in The Conversation.
Again, if accurate, these tests have serious implications for the origins of the virus. What if some Chinese tourist picked it up in Santa Catalina, Barcelona, or Baku, or Karachi, and brought it home to Wuhan sometime in the spring, summer, or fall of 2019? (It was found in Barcelona, very specifically, on March 12, 2019, so perhaps it was left there by a tourist from who knows where.)
Neither report seems to have been peer-reviewed yet, and perhaps they're just wrong. But if they're right, researchers will have to start testing oceans of sewage to see where else it might have been before Wuhan.
