HOT from the press @NatureMicrobiol: SARS-CoV-2 is likely to have diverged from the most closely related bat viruses 40–70 years ago. The findings suggest that the lineage giving rise to SARS-CoV-2 may have been circulating in bats for decades. https://www.nature.com/articles/s41564-020-0771-4

Three approaches show that SARS-CoV-2 and its most closely related relative (RaTG13) share a single ancestral lineage and estimate that SARS-CoV-2 genetically diverged from related bat viruses in 1948, 1969 and 1982, respectively.

While pangolins may have played a role in the transmission to humans, analyses of the viruses from those animals show that they are unlikely to be an intermediate host for the virus.

The authors argue that the long divergence period of SARS-CoV-2 indicates there may be unsampled virus lineages in bats that may have zoonotic potential, and that better sampling is needed to assess this.

The existing diversity and the dynamic process of recombination amongst viral lineages in the bat reservoir demonstrate how difficult it will be to identify viruses with the potential to cause significant human outbreaks before they emerge.

The study underscores the importance of more intense and systematic sampling and analyses of bat-borne viruses, especially at global hotspots of emerging infectious diseases, similar to the work by Chinese virologist Shi Zhengli and the PREDICT programme led by @PeterDaszak.

The researchers also call for real-time human disease surveillance systems that can rapidly identify and classify pathogens.