2 patients in Brazil found infected with two different variants

BRASILIA • Researchers in southern Brazil said they have discovered two patients infected with two different strains of the coronavirus simultaneously, reflecting concerns about the growing number of variants in the country.

The researchers, who posted their findings on Wednesday on medical website medRxiv, said their study would be the first in the world to confirm co-infection with two virus strains. The study has yet to be published in a scientific journal and has not been peer reviewed.

The patients, both in their 30s, were infected in late November with the P2 variant identified in Rio, also known as the B1128 lineage, and simultaneously tested positive for a second variant of the virus. Their symptoms were reportedly mild, with dry cough in one case, and coughing, sore throat and headache in the second. They did not require hospitalisation.

The cases underscore how many variants could already be circulating in Brazil and raise concerns among scientists that the co-existence of two strains in the same body could speed up mutations of new variants.

"These co-infections can generate combinations and generate new variants even more quickly than has been happening," said the study's lead researcher Fernando Spilki, a virologist at Feevale University in Rio Grande do Sul state. "It would be another evolutionary pathway for the virus."

New variants bring the risk of greater transmissibility and possible resistance to vaccines currently being developed. Mutations found in coronavirus variants in Britain and a more recent one in the Brazilian state of Amazonas appear to have made the virus more contagious.

The cases point to the significant viral load circulating in Brazil because co-infection can occur only when different viruses are being transmitted in high quantity, Dr Spilki said.

Meanwhile, the United States said on Thursday it had found on American soil its first two cases of the B1351, a highly transmissible variant of the coronavirus first identified in South Africa, leading to concern that it could reignite the national infection rate, which is currently in decline.

REUTERS, AGENCE FRANCE-PRESSE