- China has culled tens of thousands of pigs in response to outbreaks this summer
- Wild boars and human behavior are believed to be the main causes of spread in Europe
(CNN)Global health officials are preparing for African swine fever, which has been spreading in pigs across borders since 2014, reaching Western Europe last week.
Humans are suspected to have caused the recent spread to Belgium, where eight cases were confirmed, as of September 25, according to the World Organisation for Animal Health.
The most recent cases, however, were reported September 25 in a Chinese slaughterhouse in Hohhot, the capital of Inner Mongolia, according to the organization. There have been 29 outbreaks in China since the first case was reported August 3. China has culled nearly 40,000 pigs in response, according to the the organization's database.
The virus reached China this summer and arrived in Western Europe for the first time in September in a separate simultaneous outbreak, leaving officials worried.
As of Friday, Belgium had culled 4,000 domestic pigs from the Étalle region, according to the country's national federation of slaughterhouses, cutting plants and wholesalers for pork. Thirteen countries have banned some sort of pork imports from Belgium: Taiwan, South Korea, Serbia, Singapore, China, Belarus, Australia, Japan, Philippines, Mexico, Uruguay, Malaysia and India.
"An outbreak of African swine fever is a very serious event," said Matthew Stone, the World Organisation for Animal Health's deputy director general for international standards and science. "The authorities of countries affected are under extraordinary pressure."
Globally, more than 361,000 infected wild boars and domestic pigs have been reported to the organization, with more than 119,000 deaths in 2018.
The disease is characterized by pigs developing hemorrhaging lesions on their skin and internal organs. All cases can result in death within 10 days of infection, according to the World Organisation for Animal Health.
Financial consequences of an outbreak are substantial. Once the virus has been detected on a pig farm, the entire population must be culled.
Pork exports make up 8.5% of the European Union's total agricultural industry and 62% of the bloc's total meat exports, according to a 2016 US Department of Agriculture report.
Eastern Europe has witnessed several outbreaks of the virus over the summer, with Romania most affected.
The first case was reported in January near the Ukrainian border, and Romania has reported over 900 outbreaks since, mostly among backyard farm animals. Bulgaria, the Czech Republic, Estonia, Latvia, Lithuania, Hungary, Poland, Russia, Ukraine, Moldova and Romania have reported over 355,000 cases between them since 2014.
African swine fever, which affects only wild boars, warthogs, bush pigs and domestic pigs, is endemic in sub-Saharan and West Africa and was first detected in Kenya in 1921. Scientists agree that there are no health risks to humans, according to the World Organisation for Animal Health.
The disease is transmitted among pigs by direct contact with infected animal