Denmark began construction Monday of a 70-kilometer fence on the border with Germany as part of efforts to combat the spread of African swine fever through wild boar. The 1.5-meter high fence, which will run along the entire border between the two countries, is due to be completed by the end of the year.

African swine fever has been reported in some Eastern European countries, though no cases have been confirmed in Germany. The fever is not dangerous to humans, but is almost always fatal in pigs and there is as of yet no vaccine.

Danish exports of pigs and pork in 2016 were worth a total of about $4.6 billion. According to the Danish government, if the virus were to spread to Danish stocks, all exports to non-EU countries would have to be stopped. The country exported pork worth 11 billion kroner ($1.29 billion) to non-EU countries in 2016.

Earlier this month, Belgium confirmed an outbreak of African swine fever, marking a further spread of the disease that has hit farms in Eastern Europe and China and which could now threaten Western Europe's large pig industry. African swine fever has so far been detected in the Baltic States, Poland, the Czech Republic and Hungary.

Cases in wild boar were also detected in Belgium last autumn. According to Germany's Friedrich Loeffler Institute, there is a high risk of the disease spreading to Germany. Some German lawmakers have criticized the border fence, claiming the virus is spread primarily by people during the transport of animals and infected food.