China on watch for mutant African swine fever strains
- Researchers say they have found two variants that spread more easily than the dominant type
- Disease devastated pig herds in 2018 as millions were culled to contain outbreaks
In a paper published on Friday, researchers at the Chinese Academy of Agricultural Science’s Harbin Veterinary Research Institute said they carried out genetic analysis of various natural mutations of the virus found in seven provinces between June and December.
Two of the emerging strains were highly transmissible and less virulent than the dominant strain, making them more difficult to detect.
“The emergence of lower virulent natural mutants brings greater difficulty to the early diagnosis
of African swine fever and creates new challenges for control [of the virus],” they said.
02:10
China’s outbreak of African swine fever pushes pork off the Lunar New Year menu
The team also detected mutated strains that were as lethal as the prevalent strain.
The paper was published in Science China Life Sciences, a peer-reviewed journal co-sponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China.
African swine fever does not infect humans but it spread like wildfire through the country’s swine herds in 2018, killing 100 million pigs and inflicting heavy losses on farmers.
There is no commercial vaccine or effective treatment for the disease, which remains a threat to global food security.
China accounts for almost half of the world’s consumption of pork, the price of which rose to record levels last year after swine fever forced farm closures, wiped out half of the nation’s pig population and throttled supply to end consumers.
The crisis prompted the central government to tap into its pork reserves and subsidise consumers to suppress inflation.
Fitch Ratings estimated that the 2018 outbreak caused a shortfall of 4.3 million tonnes of the staple meat last year. Last year’s pork output fell 3.3 per cent to 41.13 million tonnes after falling 21 per cent in 2019.
01:20
China’s ongoing African swine fever epidemic is spreading across Asia
But experts say low standards of biosecurity, lack of oversight and local government cover-ups of outbreaks allow the disease to spread.
The disease is a global issue that arises from the competing demands of raising livestock to feed growing populations and managing the disease risks for animals and humans that come with the expansion of meat production.
Meanwhile, a US study showed in October that an emerging coronavirus strain called Sads-CoV, which causes gastrointestinal illness in swine, had the potential to jump to humans.
