#13,795
While the emergence and spread of African Swine Fever across 24 provinces and territories of China (and now, reported in Mongolia) has been the biggest ASF headline of the past year, at the same time this devastating pig virus has been making serious inroads across much of Eastern Europe and parts of Russia.
African Swine Fever (ASF) was eradicated in Western Europe decades ago, but was reintroduced into Eastern Europe in 2007. Since then it has spread rapidly east through Russia, while moving much slower towards Western Europe.In early September, however, the virus was found in wild boar in Belgium - signifying a westward jump of more than 500 km (see OIE Notification: African Swine Fever Jumps To Belgium) - raising the takes for all of western Europe.
Today we've a recently released (albeit dated November 2018) 34-page analysis from DEFRA, that examines the risks of the introduction of ASF to UK farms, and its likely economic impact.
It's not clear why the 2 month delay in publication.The upshot is that DEFRA calculates a 20% chance of seeing ASF from EU member states impacting UK farms, raising the overall risk level from `Low' to `Medium'. They also figure that an outbreak affecting 30 farms would be a “reasonable worst-case scenario”, with losses estimated between £45 and £70 million.
I've only included a few excerpts from a much longer and highly detailed report, so download the full full PDF file from the link below:
Qualitative risk assessment
What is the risk of introducing African swine fever to the UK pig population from European Member States via human-mediated routes?
November 2018
(EXCERPTS)
Current situation in the EU
In the EU during 2017, there were 123 outbreaks in domestic pigs and 3,867 in wild boar reported to the ADNS system. In 2018 (to September) there were 167 outbreaks in pigs in the same countries (PL, EE, LV, LT, CZ and HU) and 3,976 in wild boar. A slight increase in the 2017 numbers, but nothing significant. New areas in central and northern Poland on the border with the Russian exclave of Kaliningrad are the sources of these additional cases (highlighted in the maps below).
However, Romania first started to report cases in the southern region of Tulcea in May 2018 and the number of domestic pig cases has now reached over 1,200 (mainly backyard but including some large commercial farms), which is 9 fold more than the other affected countries combined. In addition, a recent incursion into Belgium in two wild boar was reported in September, which again represents another large geographic jump.
Although the source has not yet been confirmed, the most likely cause is via human-mediated routes. Previous outbreaks in Romania in 2017 were on the Northern border with Hungary / Ukraine and although the index case source was not reported, the second case was through a boar being moved to the farm for mating/insemination purposes (EFSA, 2017).
(SNIP)
Consequence assessment
The UK pig population consists of ~4 million animals (10,000 premises) in commercial pig farms, not including non-assured or small holdings or backyard pigs. The feral pig population is several hundreds in isolated populations, the largest of which is the Forest of Dean.
In terms of the impact or consequence of ASF infection this is mainly considered for the commercial sector and can be measured in terms of economic impact from high case fatality rates, requirement for culling of affected farms and the significant trade impact, particularly with respect to the valuable third country market (China and Russia) as well as EU trade.
There is no public health risk. However, even a case in a feral pig population which leads to a trade ban. Expert elicitation (unpublished) has estimated a reasonable worst case scenario and the likely economic impact based on the value of the sector and the likely number of outbreaks and time that a ban may remain in place.
Due to the small discrete populations of feral pigs, we would not expect disease to be maintained in these populations, giving rise to continual reintroductions into the domestic pigs, as seen in Eastern Europe. Nevertheless, the costs of control in a feral boar population would be substantial
Final risk estimation(Continue . . . . )
We consider there is an overall MEDIUM annual probability of introduction of ASF into the UK pig population considering all the pathways. From a management perspective, this is considered “likely”. See the table below for the risk estimates for the individual pathways
At present, the EU control measures in place in the north eastern Member States are being adhered to and are preventing spread within the domestic pig sector.
Occasional spill over events are still occurring and there is concern that given the large wild boar population and the lack of available and effective control measures for such a population (ie vaccination) the disease will persist in these areas.
Of greater concern is the area where there is a high level of backyard herds becoming infected but only few wild boar cases, which suggests different transmission pathways are involved and a general lack of biosecurity. Only Romania is in this situation. With up to ten new outbreaks reported each day, culling and testing capabilities will be stretched.
Spill over into commercial pigs may occur and the slow moving nature of the infection and high infectiousness of pigs before they show clinical signs means the possibility for an infected pig entering the food chain without being identified is possible.
Although this document envisions a reasonable worst case of ~20–30 farms affected, the ability of other affected countries to control and contain this disease over the past decade has not been particularly encouraging.
Below you'll find a table of likely ways the virus could be introduced to the UK.
While the biggest risks for the spread of ASF right now are undoubtedly in Asia and Europe, their are concerns over seeing it arrive in North America someday as well.
Last November the USDA released a new African Swine Fever Factsheet that discusses their preparations for a possible introduction of the virus into this country.
(Excerpt)
Keeping ASF Out
Because of the concern over ASF, USDA recently reviewed and further strengthened its longstanding stringent protections against the spread of the disease.These include:
- Collaborating with states, industry and producers to ensure everyone follows on-farm biosecurity and best practices (including for garbage feeding in states where that is allowed);
- Restricting imports of pork and pork products from affected countries; and
- Working with CBP staff at ports of entry to increase passenger and baggage screening for prohibited products from affected countries.
