More than half a million pigs were culled in the past two weeks in Vietnam, bringing the total killed so far to 1.7 million.
African swine fever is spreading across the country, with threats of reaching commercial farms next.
The number of pigs culled is equivalent to 5 percent of the country's herd population. There has been no available vaccine and medicine for treating the contagious disease in animals.
Highly Contagious African Swine Fever Virus
According to the Food and Agriculture Organization, the African swine fever is a fatal animal disease affecting pigs and wild boars of all ages with up to 100 percent mortality. It is a highly contagious, generalized disease of pigs caused by an Iridovirus of family Asfarviridae.
The agent can remain viable for long periods in blood, feces, and tissues of infected animals. The disease commonly manifests in the acute form as hemorrhagic fever and can also multiply in its vectors.
"The control of ASF is dependent on stamping out policy and strict quarantine enforcement," the FAO said in an update.
The virus persists in three distinct cycles: the sylvatic cycle, the tick-pig cycle, and the domestic or pig to pig cycle.
ASF Outbreak In Vietnam And Other Asian Countries
As of May 23, the countries affected with ASF are China, Vietnam, Mongolia, and Cambodia. The ASF virus that was first detected in Vietnam in February, has spread to 42 out of its 63 provinces.
Outbreaks may even occur in locations where there have been no new cases for at least a month, according to officials. Rains and flooding in the southwestern region of the Mekong Delta have worsened the spread of the disease and affected the burial of culled pigs.
"The African swine fever outbreak is the most dangerous and costly of its kind in the husbandry industry of Vietnam," said Nguyen Xuan Cuong, agriculture minister of Vietnam.
The official further said it is difficult to contain the outbreak because the virus remains dormant in the environment for a long time and can spread through complex and various ways.
Actions Taken By Vietnam
Vietnam has implemented movement control of pigs and pig products from affected communes. ASF positive farms have been depopulated according to the government's Action Plan for Emergency Response.
In Vietnam's "pig capital" Dong Nai province, authorities will prosecute farmers who will fight against the culling of their sickened pigs. Slaughtering of infected pigs for meat is still occurring in the province. The government will also mobilize military and police forces to help combat the outbreak.
Authorities are encouraging the rearing of poultry, cattle, and other livestock to make up for the possible shortage of pork. Most of Vietnam's 30 million farm-raised pigs are consumed domestically.