Assam has reported the first instance of African swine fever in the country in Assam where the disease has killed around 2,900 pigs across 306 villages of the state.
Assam’s animal husbandry minister Atul Bora has said, despite the go-ahead from the Centre, the state government will not cull the animals immediately and choose an alternative option to prevent the spread of the disease.
African swine fever, Atul Bora has said, was detected towards the end of February this year, but it started in April 2019 at a village in Xizang province of China bordering Arunachal Pradesh.
What is African swine fever?
African swine fever (ASF) is a severe, highly-contagious hemorrhagic viral disease of domestic and wild pigs. This transboundary animal disease (TAD) can be spread by live or dead pigs, domestic or wild, and pork products.
It is caused by a large DNA virus of the Asfarviridae family, which also infects ticks of the genus Ornithodoros.
Signs of African swine fever and classical swine fever (CSF) may be similar but the ASF virus is unrelated to the CSF virus.
African swine fever is a disease listed in the World Organisation for Animal Health (OIE) Terrestrial Animal Health Code and must be reported to the OIE.
Transmission and spread
{{/usCountry}}Transmission and spread
{{/usCountry}}Routes of transmission can include direct contact with infected domestic or wild pigs.
It can be through indirect contact by consumption of contaminated material—food waste, feed, garbage, contaminated fomites such as shoes, clothes, vehicles, knives, equipment, due to the high environmental resistance of ASF virus.
It can also be transmitted through biological vectors—soft ticks of the genus Ornithodoros where present
Public health risk
African swine fever is not a risk to human health. While swine flu can spread from animals to humans, African swine fever does not and therefore is not a public health threat.
Signs of African swine fever
Signs and mortality rates can vary according to the virulence of the virus and the type/species of pig.
Acute forms of ASF are characterised by high fever, depression, anorexia and loss of appetite, haemorrhages in the skin (redness of skin on ears, abdomen and legs), abortion in pregnant sows, cyanosis, vomiting, diarrhoea and death within 6-13 days (or up to 20 days). Mortality rates may be as high as 100%.
Subacute and chronic forms are caused by moderately or low virulent viruses, which produce less intense clinical signs that can be expressed for much longer periods. Mortality rates are lower, but can still range from 30-70%.
Chronic disease symptoms include loss of weight, intermittent fever, respiratory signs, chronic skin ulcers and arthritis.
Different types of pigs may have varying susceptibility to ASF virus infection. African wild suids may be infected without showing clinical signs allowing them to act as reservoirs.
Diagnosis
African swine fever may be suspected based on clinical signs but confirmation must be made with laboratory tests, particularly to differentiate it from classical swine fever (CSF).
Prevention and control
Currently, there is no approved vaccine for ASF.
Geographical speed
Historically, outbreaks have been reported in Africa and parts of Europe, South America, and the Caribbean.
More recently, since 2007, the disease has been reported in multiple countries across Africa, Asia and Europe, in both domestic and wild pigs.
China has been battling African swine fever since August 2018, after the disease spread rapidly throughout the world’s top pork producer, killing millions of pigs and sending pork prices soaring.
African swine fever was first detected in 1921 in Kenya.
(Sourced from the World Organisation for Animal Health)