SINGAPORE (Reuters) - A COVID-19 outbreak at Singapore's airport may have initially spread through a worker who helped an infected family arriving in the country, authorities said on Friday, as they further ramped up their testing regime.
The airport cluster which involves about 100 cases, is part of a resurgence of infections in the Asian business hub and highlights the challenges of keeping the virus out, despite rigorous testing and quarantine measures for travelers. It is Singapore's largest active cluster.
The civil aviation regulator and the Changi Airport Group in a statement said test results from a batch of staff were similar and were of the B.1.617 variant, first found in India, suggesting they "originated from a common source".
"Preliminary investigations indicate that the initial transmission could have occurred through an airport worker who was assisting a family from South Asia," it said. The family arrived on April 29.
Earlier this month, Health Minister Ong Ye Kung said many infected airport staff worked in a zone that received travelers from high-risk countries. The workers may have infected others in the airport's food outlets, he said.
The airport has since tightened measures by ringfencing teams working with arrivals from higher-risk countries. It also segregates travelers from different risk profile countries, so they use different immigration halls, baggage belts and toilets.
So far about 90% of frontline aviation workers have been vaccinated against COVID-19.
Authorities on Friday said there would be more testing for passengers from very high risk countries and airport workers in higher risk roles.
The B.1.617 variant has been found elsewhere in Singapore, which has recently tightened restrictions.
Though Singapore's cases are only a fraction of those recorded in neighboring countries, the outbreak follows months of reporting few or no local cases each day. The city-state has recorded 190 cases over the past week.
Teo Yik Ying, dean of the Saw Swee Hock School of Public Health at the National University of Singapore, said the B.1.617 variant was much more transmissible.
" This means the strategies for border control and infection prevention, which previously have worked well for the past six months, are proving to be insufficient," he said.
(Reporting by Aradhana Aravindan in Singapore; Editing by Martin Petty)