Coronavirus cases in Brazil have different genomes

The genome of the new coronavirus from the sample collected from the first patient diagnosed in Brazil is different from that of the second. They are also different from the sequence mapped from patients in China. This may indicate that internal transmission itaking place within Europe.

“The first isolated sample proved genetically more similar to the virus mapped in Germany. This second genome, in turn, is more similar to the one sequenced in England. Both are different from the Chinese ones. This suggests that the coronavirus epidemic is maturing in Europe—in other words, internal transmission is happening in European countries. For a more accurate analysis, we need the data from Italy, which haven’t been sequenced yet,” said Ester Sabino, director at the Tropical Medicine Institute (IMT) of the University of São Paulo (USP).

The first case of the new coronavirus in a Brazilian resident was reported on February 26. Two days after the confirmation, scientists were able to complete the first genetic sequencing of the new coronavirus (Covid-19) in Latin America. The second case in Brazil was confirmed on February 29. Both patients live in São Paulo, but were recently in Italy.

Sequencing

Efforts to sequence the virus have been conducted by scientists from a number of academic and research institutes, with the aid of the UK–Brazil Joint Centre for Arbovirus Discovery, Diagnosis, Genomics and Epidemiology (CADDE), a network of researchers dedicated to respond and analyze data on epidemics in real time.

In order to carry out the viral sequencing with real-time monitoring, the group avails itself of a portable device known as MinION, used for the first time in the country in 2016 to observe the evolution of the Zika virus.

According to the IMT researcher, the main advantage of monitoring an epidemic in real time is being able to identify where exactly the virus that reached the country came from, which helps devise measures to reduce the spread of the disease.

Claudio Tavares Sacchi, in charge of the Strategic Laboratory of the Adolfo Lutz Institute, the goal is to sequence the virus genomes in every confirmed case in the country. “But if the positive cases start to multiply on large scale, the sequencing will be based on sample and statistics, so that the cases samples are representative of the total,” he said.