Ever since the first case of African swine fever (ASF) was first detected in the Lunglei district of Mizoram on March 23, the northeastern state has so far culled at least 9,000 infected pigs. 

Globally, the disease is so far the deadliest outbreak amongst the animals as it has been responsible for the deaths of at least 10 million pigs worldwide.

The outbreak of African swine fever has paralysed the pork business in the state with customers avoiding pork consumption and butchers as well as farmers reeling under losses despite pork being sold at higher prices.

The outbreak has previously been reported in the neighbouring state of Assam in May, last year. Assam witnessed the culling of almost 20,000 pigs as a measure to control the outbreak. The outbreak in Assam was the first time India reported  cases of African swine fever and the disease soon spread to the neighbouring states of Mizoram, Arunachal Pradesh, Nagaland, Meghalaya, and Manipur. It has been stabilised in almost every state except Mizoram.

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Globally, countries that have recorded the outbreak in significant numbers include Mongolia, China, South Korea, Philippines, Indonesia, and Malaysia. 

What is the African swine fever?

The African swine fever is caused by a virus which is named after the disease itself (African swine fever virus [ASFV]) — it is a DNA virus belonging to the Asfarviridae family of viruses. 

Although the ASFV cannot infect human beings, its outbreak is highly lethal for the pig populations as it has a fatality rate of almost 100 per cent.

Presently, the African swine fever virus has a total of 24 genotypes and all of them have been linked to Africa.

How did the disease come into being?

The ASF was first reported in the east African nation of  Kenya in 1910.

It was then reported from Zambia in 1912 and 1914, and made its way to South Africa in 1928. The present status of ASF is that of an endemic in southern African countries.

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As per the Paris-based World Organisation for Animal Health, Portugal was the first European country to report ASF in 1957. Then, in 1960, it soon spread to Spain, France and Italy, and remained to be an  endemic till 1995. It has now been reported to be eradicated in Europe with the exception of the Italian island of Sardinia in the Mediterranean sea, where it has become endemic.

In 2007, the disease was reported from Russia and the Caucasus region with incidence in countries like Belarus, Azerbaijan, Armenia and Georgia.

The virus first reached the Americas through Cuba in 1971, where 500,000 pigs were culled to prevent its spread. Starting with Brazil in 1978, it spread to Dominican Republic and Haiti. But at present the disease is under control in South and North America.

Also Read: African swine fever rages on in Assam

The ASF reached Asia in 2019 when countries like Vietnam, Hong Kong, Cambodia, Laos and China began to report its outbreak. The infection in India’s northeast is said to have been contracted from supply of pigs from China’s Tibet.

How to control the spread of African swine fever?

At present, there is no cure or vaccine for the ASF and culling of the infected pigs is the only measure to control its outbreak. 

Rapid culling of all infected pigs and proper disposal of cadavers and litter is essential as per the  World Organisation for Animal Health. 

The agency also advises that the disease can be prevented by ensuring a careful import policy for animals and animal products. Also, proper disposal of waste food from aircraft or ships coming from the infected countries must be taken care of along with careful sterilisation of the garbage.