Governments around the world are urgently scouring databases for recent cases of COVID-19 infections, screening travellers and decoding the viral genomes of the new variant as they try to measure how far it has spread.
The pace of the work highlights the pressure on governments and public health authorities to decide quickly whether they need to take unpopular, economically damaging steps to curb Omicron’s spread.
Data shows it was circulating before it was officially identified in southern Africa last week and it has since been detected in more than a dozen countries. Work to establish if it is more infectious, deadly or evades vaccines will take weeks.
Britain and other major economies banned flights to and from southern Africa just days after the variant was first detected, roiling global financial markets and stirring worries about the economic damage.
Scotland and Singapore are scrambling to check tens of thousands of recent positive cases for signs of the variant they may have missed and the United States is enhancing its COVID-19 surveillance to distinguish domestic cases of the Omicron variant from the still dominant Delta.
The European Union’s health commissioner has urged member states to boost efforts to detect mutations, as some still lag behind almost two years into the pandemic.The bloc has now confirmed 42 cases in 10 countries.
Most PCR tests cannot distinguish Omicron from the Delta variant, the dominant and most infectious version of the virus so far.To distinguish Omicron from Delta, the PCR test must be able to identify a mutation in Omicron known as the S-gene drop-out or S-gene target failure .
It has so far only recommended the TaqPath test produced by U.S. firm Thermo Fisher as a proxy.Thermo Fisher has said it is prepared to increase production to meet demand from countries in Africa and elsewhere as they work to track the spread of the new variant.
Most U.S. labs will be using the TaqPath test, Scott Becker, chief executive of the Association of Public Health Laboratories (APHL), a network of state and municipal public health laboratories, told Reuters.
Out of the 150,000 positive tests going back a month assessed in Belgium, 47 had S-gene drop-out and a high viral load. Only one of them was Omicron, according to Marc Van Rast, one of the virologists who parsed the samples.
