Hong Kong has been urged to slaughter local pigs separately from those imported from mainland China over fears of a rapid spread of African swine fever that has already caused more than 24,000 pigs to be culled.
“People can take infection from the slaughterhouse back to the farm,” said Dirk Pfeiffer at City University’s College of Veterinary Medicine and Life Sciences. “You need to separate that completely. Slaughter the local pigs in a different slaughterhouse and the mainland [Chinese] pigs have their own chain.”
Hong Kong imports about 4,000 live pigs a day from the mainland, while about 290 pigs are supplied daily by local farms.
The UN’s Food and Agriculture Organisation (FAO) warned on Tuesday the rapid onset of African swine fever in China, and its detection in areas more than 1,000 kilometres apart, could mean the deadly pig virus may spread to other Asian countries at any time.
There have been four outbreaks of the highly contagious swine disease on the mainland this month. It was first reported on Aug 3 in the northeastern city of Shenyang. The virus causes a haemorrhagic fever with high mortality rates in pigs. The most virulent forms are lethal in 100% of infected animals.
It can be spread by eating the product or through direct contact with secretions from the infected pig, but it does not affect people. The virus can persist for long periods in uncooked pig products.
“We don’t know what the situation is,” Pfeiffer said. “What we know is we’ve had four outbreaks of the virus that have been reported in almost four weeks, but like many outbreaks, the question is how many other farms and animals are already infected.”
Pfeiffer, who is with the college’s department of infectious diseases and public health, said Hong Kong authorities needed to do their utmost to keep the virus out of the city given no cure or vaccine for it exists.
Live pigs for local consumption are sourced from registered farms in Guangdong and Jiangxi provinces, which come under the supervision and monitoring of the mainland authorities, a spokesman for the Centre for Food Safety said.
“Every consignment of pigs [for food] must be accompanied by an official certificate attesting that the animals are healthy and showed no clinical sign of infectious diseases,” the spokesman added.
Consignments are also inspected at the border and at slaughterhouses.
The Agriculture, Fisheries and Conservation Department reminded local pig farmers to step up biosecurity measures, a spokesman said.
The department will continue to communicate with mainland authorities about the disease and “stay vigilant to monitor” its risk.
A small number of breeding pigs are also imported into Hong Kong each year from Guangdong. They must be accompanied by an official health certificate issued by the mainland authority. The animals are inspected by the department’s officers upon arrival and are quarantined thereafter.
China is a major pig-producing country and accounts for about half the global population of pigs, estimated at 500 million, the FAO said.
Howard Wong Kai-hay, director for professional development at City University’s college of veterinary medicine, agreed Hong Kong should be prepared as an outbreak of African swine fever in pork would be “a much bigger disrupter of communities than chickens”.
“We should always be prepared, we should always have the option so we should know what to do,” Wong said.
In previous years, the city has culled thousands of chickens due to avian flu scares.
Pfeiffer and Wong believed the veterinary school could help officials design measures to help prevent the introduction of the virus and conduct risk assessment.
“Hong Kong does not have a porous border with China,” Wong said. “With proper risk assessment, it should be possible to come up with ways to minimise the risk to Hong Kong and then that has to be taken up by the government.”
The South China Morning Post reported on Monday that agricultural officers across China had been ordered to control the spread of African swine fever.
Pfeiffer, who has been researching the virus since 2005, said it could have spread out of Africa by infected food waste from ships or airliners that had been sold to pig farms.
“It’s an animal disease, but because of the social issues, it’s about food supply, people’s livelihoods,” he added.
The strain detected in China is similar to one that infected pigs in eastern Russia in 2017.
“The movement of pig products can spread diseases quickly and, as in this case of African swine fever, it’s likely that the movement of such products, rather than live pigs, has caused the spread of the virus to other parts of China,” FAO’s chief veterinarian Juan Lubroth said.