First report of patients being infected with two coronavirus strains

The Brazilian cases raise fears that new COVID-19 variants are mutating faster

Researchers in southern Brazil say they have discovered patients infected with two different strains of COVID-19 simultaneously.

The researchers, who posted their findings on the medRxiv preprint server, say their study is the first in the world to confirm co-infection with two strains of the virus.

The study has yet to be published in a journal and peer-reviewed.

The patients, both in their 30s, were infected in late November with the P.2 variant of coronavirus first identified in Rio de Janeiro,