African swine flu (ASF) is a haemorrhagic fever that affects domestic pigs as well as wild boars. It is caused by the African swine flu virus (ASFV), a large DNA virus from the Asfarviridae family.
ASF does not affect humans. However, it can have a high economic cost. This is because farm pigs usually have to be culled by the thousands to contain its spread.
India reported its first-ever cases of ASF in Assam and Arunachal Pradesh on May 3, 2020. Here's what you need to know about this viral infection in pigs:
What are the symptoms of ASF?
ASFV causes high fever, lesions, elevated pulse and heart rate, nausea, bloody diarrhoea, reddening of the ears and snout in pigs. The incubation period of the virus is 5-15 days, which is usually followed by death.
Where did the virus come from?
The virus, which is highly contagious and often lethal to pigs, was first identified in Kenya in 1910. It has since spread to most Sub-Saharan African countries, European countries such as Greece, Spain, Italy and Portugal, some Caribbean countries and China as well. (Reportedly, the virus had affected 40% of China’s pigs by 4 May 2020.)
How does this virus spread?
ASFV spreads through direct contact between infected pigs and healthy pigs. Indirect transmission in pigs is also possible through fomites (common use objects), certain vectors such as ticks and through eating infected animal feed; it is believed that ingestion of infected meat products by pigs caused the spread across continents.
Why is everyone talking about it?
The World Organisation for Animal Health has classified ASF as a notifiable disease, as it has a high mortality rate among pigs. This means that animal farmers have to report it if they notice any signs of the disease in their livestock.
India reported its first case of ASF in Assam in the first week of May 2020. As of 4 May 2020, 2,800 pigs had died of the infection in the NorthEastern state.
Does African swine fever affect humans?
While the virus does not affect humans, infectious disease specialists warn that it is possible for the virus to mutate. If this happens, it would not be the first time a pathogen can jump from a pig to humans (zoonotic transmission). An example of this already exists in Swine flu or H1N1.
What happens if you eat meat infected with African swine flu?
Eating pork infected with this virus does not pose a risk to humans, according to the German Federal Institute for Risk Assessment (BfR). That said, the institute also advises against eating undercooked meat or meat prepared in unhygienic conditions.
What is the difference between African swine fever and swine flu?
African swine fever (ASF) is a viral disease caused by a large double-stranded DNA virus which affects both wild and domesticated pigs. It is highly contagious among the species and can be fatal, and there isn't a vaccine available for it. And, ASF isn't known to cause disease in humans.
Swine flu, on the other hand, can affect humans. It is caused by the H1N1 RNA virus strain. There are vaccines to prevent swine flu now. The key signs of swine flu in people include fever, chills, sore throat, runny nose and watery eyes. While it can jump from pigs to humans, swine flu is not known to spread through pork products.
Is there any treatment or vaccine for ASF?
There is currently no vaccine or treatment for ASFV. If the viral strain is detected in a swine population, the animals are culled to prevent the further spread of infection.