State labs to start deep analysis of Covid-19 genetic make-up

Close analysis of cases could help with tracing in potential second wave

The State’s virus-testing laboratories plan to start testing the genetic make-up of coronavirus in confirmed Covid-19 cases in a move that could help suppress emerging clusters of infection.

The additional testing could help public health officials better tackle a potential second wave.

Analysing the genetic sequence – a kind of barcode that identifies the make-up of the virus in each positive case – could help map how the virus is spreading and prevent further transmissions.

Viruses evolve over time, and assessing the genetic sequence in a Covid-19 case could help trace how the person became infected and whether the virus is related to a cluster in a workplace or hospital or to travel if there are similarities to the sequence of the virus in another country.

The State’s labs have until now been testing to diagnose whether or not a person is infected but, given the low number of cases, they intend to start looking in more detail at the genetic make-up of the virus found in individual cases to find the source of the infection.

"We have been intending to do this for a while but the laboratories were so busy from a diagnostic perspective, just getting through the numbers, that we weren't in a position to do this additional analysis earlier," said Dr Cillian De Gascun, director at UCD's National Virus Reference Laboratory.

“We were hoping to add the genetic data from the virus and pair that with the surveillance information or the contact-tracing information and try to put all of that together,” said

Genetic sequencing

Dr De Gascun, who is chairman of the expert advisory group to the State’s National Public Health Emergency Team, said the analysis would be a “significant piece of work” but that he was hoping it could be done “in real time” to add to the public health investigations into the virus.

Genetic sequencing could identify whether infections were similar and help trace the virus to a geographical area, which would in turn manage the public health response to suppress the spread.

“It is likely it won’t help in every situation but it may help in particular outbreaks,” he said.

Dr Paul Cotter, a microbiologist at UCC, who is leading a separate State-funded research project assessing the genetic make-up of Covid-19 viruses circulating in Ireland, said that the virus undergoes small mutations as it moves that serve as a barcode for its origins to places or countries.

“If there were to be a second wave, this would be even more powerful in tracking things down in real time rather than using people power and phoning people in contact tracing,” he said.