Yantian International Container Terminals, which handles cargo at one of the world’s busiest container ports, will restore normal operations after a Covid-19 outbreak caused a month of disruptions that snarled global supply chains and led to a surge in shipping rates.

All berths at the port of Yantian, part the Port of Shenzhen in southern China, will be fully operational on Thursday as the virus situation is now under control, Yantian International said in a statement. The company closed three berths on May 21 to address the outbreak, which infected some of its workers.

Major shipping lines such as A.P. Moller Maersk A/S and Mediterranean Shipping Co. have been avoiding the port, where tighter health and safety checks resulted in congestion and slowed productivity. That in turn led to bottlenecks at other ports and added more pressure to supply chains already stretched by the pandemic and the Ever Given blockage of the Suez Canal in March.

The disruptions in Shenzhen, the world’s fourth-busiest container port, have sent shipping costs to record highs. Spot rates for 40-foot containers to Los Angeles from Shanghai have jumped 11% this month, according to Drewry World Container Index, while Shanghai to Rotterdam rates are up 10%.