New Delhi: Delhi has extended the “14-day quarantine” order on passengers arriving from the United Kingdom till January 31. The quarantine was placed following the spread of a highly infectious strain of the virus in the UK.  India has so far logged 109 cases of the UK strain of the virus. Seven of them were detected in the last 24 hours.The UK strain of virus — said to be 70 per cent more contagious — has reached Denmark, Netherlands, Australia, Italy, Sweden, France, Spain, Switzerland, Germany, Canada, Japan, Lebanon and Singapore.To put brakes on the virus in India, the Centre has embarked on a huge genome sequencing project involving 10 laboratories across the country. On the list are those of the 33,000 passengers, who tested positive for coronavirus on their return from UK.The government is also tracing and testing passengers who reached the country from abroad over 14 days in December.