New Zealand’s mysterious new coronavirus outbreak did not originate from frozen food shipments, the country’s health department said on Tuesday.
“Seems clear now that the possibility is being ruled out from that investigation,” said Director General of Health Ashley Bloomfield, according to Reuters. He did not provide specifics on the probe but said a full report on it will be released later this week.
Frozen food shipments were the primary suspect in the New Zealand investigation. One of the infected people worked in a cold storage unit, and the virus has been proven to survive in colder environments—like refrigerated supply lines—for a longer period of time.
Ruling out the shipments leaves a huge question mark over the origin of the outbreak, which broke New Zealand’s 102-day streak of no locally transmitted cases.
Public health authorities in New Zealand are still investigating the outbreak, which began on Aug. 11 when four family members in Auckland, New Zealand’s biggest city, tested positive for the coronavirus. A total of 69 active cases—out of 90 nationwide—are linked to the Auckland cluster. New Zealand reported 13 new cases on Tuesday.
New Zealand’s government had declared the country virus-free in June and lifted all restrictions apart from border controls. The new cases prompted authorities to send Auckland back into lockdown and place restrictions on other parts of the country. Prime Minister Jacinda Ardern announced on Monday that national elections planned for September would be delayed four weeks because of the outbreak. As of Tuesday, New Zealand had 1,293 confirmed cases and 22 coronavirus-related deaths.
The virus’s tendency to survive longer in the cold bolstered New Zealand’s frozen food shipment theory. Other countries likewise have suspected frozen food as a culprit in recent outbreaks. Officials in southern China’s Shenzhen last week found traces of the virus on chicken wing shipments imported from Brazil. (Shenzhen is currently experiencing a new outbreak.) Authorities in Guangzhou, another southern Chinese city, on Sunday suspended imports of frozen meat and seafood from COVID-19 hotspots over concerns of virus transmission.
In such instances, health officials have not detected virus particles in the food itself, and there is no evidence of food-borne transmission. Rather, they’ve found traces of the virus on surfaces like cold shipping containers and packaging; those remnants can infect people who come into contact with the cargo.