African Swine Fever: A novel threat to the piggery sector in Assam

May 17, 2020

400

Deepanjali Kalita*

4^th Year Student, B.V.Sc. & A.H.

Lakhimpur College of Veterinary Science, Assam Agricultural University,

Joyhing, North Lakhimpur-787051, Assam, India

Currently, world is taking precautions against novel COVID-19 pandemic, while subsequently another dangerous disease is creating havoc to the piggery sector in this critical situation i.e. African Swine Fever (ASF). African Swine Fever(ASF) or (synonyms- African pig disease or Wart hog disease) is a highly contagious fatal haemorrhagic viral disease of domestic and wild pigs (with up to 100% mortality) which causes severe economic and production loss to the pig industry (OIE, 2018; FAO, 2001). Though ASF is not a risk to human health but it is adversely affecting the livelihood security of thousands of people by losing their livestock. Unfortunately, there is no approved treatment or effective vaccine available against ASF till date unlike Classical Swine Fever (CSF) or hog Cholera which is caused by a different virus (OIE, 2018). Although signs of ASF and CSF may be similar, the ASF virus is unrelated to the CSF virus. Bio-security, control and prevention measure is the only way to save the piggery sector since there is no commercial vaccine available in the market till date. Initially African Swine Fever disease was recorded in Kenya in Africa and was confined to Africa continent upto 1957. Afterwards the disease has spread to multiple countries across Africa, Asia, China and Europe due to importation of pigs, pork or pork product from epizootic countries.

Assam ranks first in pig population in India and it is acknowledged that 2.10 million out of 9.06 million pig is contributed by state Assam (20^th Livestock Census, 2019). According to recent newspaper publications, pigs were dying since few weeks. The ICAR-National Institute of High Security Animal Disease (ICAR-NIHSAD), Bhopal has confirmed the disease as ASF by laboratory diagnosis. Recently, more than 13,000 pigs died in Assam due to ASF, making the state epicenter of ASF in India. The disease has also been reported in few districts of Arunachal Pradesh bordering Assam. The concerned authorities of the state are putting all the effort to combat the disease spreading.

ASF is caused by a DNA virus of the Asfarviridae family. It also infect the ticks of the genus Ornithodoros. The disease is limited to all breeds and types of domestic and wild pigs. All age groups are equally susceptible.

How ASF is transmitted?

The virus is transmitted by biological vectors (soft tick of the genus Ornithodoros). Usually it is transmitted via direct contact, excretion and secretions of the infected domestic and wild pigs. Indirect contact through ingestion of contaminated materials (eg. food waste, feed or garbage) can results into ASF. Also the disease is transmitted by ingestion of uncooked contaminated pork or pork products, import and export of pork or pork products from one place to other. Movement of pigs and human from infected area or infected pig farm to disease free area or pig farm can also transmit the disease.

In ASF, Clinical signs and mortality rates vary from 0-100%, depending on the virulence of the virus with which pigs are infected. The disease is mainly characterized by a short incubation period of 3-7days, followed by high fever (upto 42 degree Celsius) and death in 5-10 days. Affected animals show signs of high fever (upto 107 degree Fahrenheit), hyperaemia of the skin of the ears, abdomen and legs, bleeding from nose or rectum, respiratory distress, anorexia, depression, extreme weakness of the hind quarters and difficulty in walking, disincline to move, blood in diarrhoea and vomit, purulent nasolachrymal secretions, abortion in pregnant pigs. At present, there is no treatment or vaccine available for ASF. Hence, bio-security, control and prevention measure is the only way to save the piggery sector at present.

Some advisories to pig farmers regarding prevention and control against ASF:

Regular monitoring of health of pigs in the sty is highly essential. If any animal shows the clinical signs like loss of appetite, weakness, depression, coughing, fever, etc. then immediately separate the suspected animal from the healthy animals and consult with nearby veterinarian as soon as possible. Farmers are advised to strictly follow the rules of bio-security measures against the ASF:

Regular cleansing or disinfecting the pig sty and its surrounding.
Regular disinfection of vehicles, equipment, footwear and clothing.
Prevent entry of people other than farm attendant.
Prevent direct transmission between suspected/infected pig and susceptible pigs.
Prevent the movement of pigs or people to infected area or pig farm.
Prevent contact of domestic pigs with wild pigs.
Isolation of diseased pig.
Quarantine the newly acquired pigs from the herd for about 30 days before mixing into the pig farm.
Follow appropriate disposal of carcasses and manure.
Do not feed uncooked feed, waste or garbage.
Check infected regions before import of goods.
Infected carcasses, animal products and bedding must be burnt or buried deeply.
Strict quarantine and slaughter should be adopted to prevent further spread of the disease.
Control of ticks and other vectors by physical, chemical and biological means.

Conclusion:

Currently African swine fever is major threats to pig production in India. As there is no treatment and effective vaccine available against ASF, bio-security measures are the only key to prevent its spread between and within domestic pig farm.

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