How countries are using genomics to help avoid a second coronavirus wave

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- ^^Studies already show that outbreaks tend to be shorter and smaller when genomics is used to help contact tracing^^

- As SARS-CoV-2 spread around the world, distinct lineages began to form as viruses circulating in different regions gradually evolved. By comparing sequences, researchers can quickly rule out possible lines of transmission if two sequences don’t match, or link together cases that do.

- Scientists in the United Kingdom, the United States and other countries are also sequencing SARS-CoV-2 from a large proportion of cases there, but because their epidemics are still ongoing and case numbers are high, genomics is being used to monitor spread and help identify the source of some cases where contact tracing fails.

- The sequence data has helped resolve the true source of exposure for a health-care worker, proving that they contracted the virus at a social event and not from a patient in hospital. “Without genomics, and only interviewing, you would never be able to tell which one it was,” Seemann says. The information prevented the need for an investigation into a possible outbreak at the hospital, he says.

- The genomic data will be particularly important when regional travel resumes. Borders for all states in Australia have been closed since March, but new infections are expected when they reopen. Over the past two months, viral genomes will have mutated just enough to tell whether they come from outside the state, researchers say. “As soon as we get the sequence, we’ll be able to tell whether it came across the border or not,” Seemann says.

- Loman notes that global genomic surveillance will be important when international travel resumes.

- But the use of genomic analysis to help contact tracing is largely restricted to high-income countries, says Meru Sheel, an epidemiologist at the Australian National University in Canberra. She would like to see genomics considered as a tool for outbreak responses in resource-limited countries in the Asia–Pacific region, as it was in the Democratic Republic of the Congo, Sierra Leone and Guinea during the Ebola outbreak.