German authorities said five more wild boars have tested positive for African swine fever near where the nation’s first case was found last week and which prompted some countries to ban imports.

While no infections have been found so far at farms, the new cases highlights the contagious nature of the disease, which is often deadly for pigs and has no known cure. Several key buyers, including China, Japan and South Korea, have banned pork imports from Germany — the European Union’s top pork producer — since it confirmed the virus.

Germany can still ship meat within the EU under certain conditions, but livestock prices have taken a hit after the discovery last week. Pig costs dropped 14 per cent from a week earlier to 1.27 euros ($1.50) a kilogram as of Friday, and the pork market faces massive uncertainty, according to pig farmers group ISN. At the same time, hog futures have climbed in the US, a rival exporter.

The new cases reported by the ministry of health in the state of Brandenburg have yet to be confirmed by the federal Friedrich-Loeffler-Institute. All of the boars were found in the risk area of Oder-Spree in eastern Germany. Four of them were found dead.

In view of the degree of decomposition of the first wild boar carcass, we assumed that more fallen game would be found, Torsten Staack, Managing Director of ISN, said in a statement. Additional reports are likely, and the nation should continue its intensive search for more infected pigs, he said.

The affected area is near the border with Poland, which has faced growing cases of the disease over the past year. By comparison, Germany’s key pig-farming region is in the northwest.

“We must now do everything to combat ASF in wild boars and prevent it from spreading,” Joachim Rukwied, head of German farmers association DBV, said on Monday. “The drastic cut in producer prices on Friday is excessive and unacceptable.”