How ASF Spreads
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After smoldering in Eastern Europe and Russia for a decade, ASF arrived in China in the summer of 2018, and quickly spread across that nation killing a much as half of their pig population (see African Swine Fever In China: Epizootic or An EpicZootic?).
ASF is often spread - at least locally - via infected pigs and wild boars (or by infected ticks), but the virus can live for weeks or even months in infected food products, and exported pork products are believed to be a major cause of the international spread of African Swine Fever.
Although ASF has never been reported in North America, it did return to the island of Hispaniola in the summer of 2021 (see USDA Statement On Detection Of ASF In Haiti) following a 40 year absence, and the potential for seeing it here someday is quite real, where the costs to agricultural interests could run into the billions of dollars.Hong Kong has reported a few scattered detections of ASF in local pigs - likely shortly after being imported from the mainland - over the past 5 years, but has managed to quickly eradicate the disease each time (see 2019's Hong Kong: ASF Detected For A Second Time At Local Slaughterhouse).
That winning streak appears to have ended last November with Hong Kong's AFCD Reporting:
- A case of African swine fever announced by a licensed pig farm in Lau Fau Shan, Yuen Long on November 7, 2023
- A case of African swine fever announced on November 23, 2023 by a licensed pig farm in Lau Fau Shan, Yuen Long
In December, 4 more outbreaks were reported:
- The African swine fever case announced by the San Tin Yi licensed pig farm in Yuen Long on December 9, 2023
- A case of African swine fever announced on Dec 23, by a licensed pig farm in Lau Fau Shan, Yuen Long,
- The African swine fever case announced by San Tin Yi licensed pig farm in Yuen Long on Dec 28, 2023
- The African swine fever case announced by San Tin Yi licensed pig farm in Yuen Long on Dec 30, 2023
In the first 3 days of the new year, 2 more farms have been reported as infected:
- (AFCD) announced (January 2) that African swine fever virus was detected in pig samples from a Yuen Long pig farm.
- AFCD) announced (January 3) that African swine fever virus was detected in pig samples from a Sheung Shui pig farm.
Excerpts from today's announcement from HK's AFCD follow:
The Agriculture, Fisheries and Conservation Department (AFCD) today (January 3) announced that samples taken from a pig farm in Sheung Shui had tested positive for the African Swine Fever (ASF) virus.An AFCD spokesman said, "Six samples were taken at a licensed pig farm in Kwu Tung, Sheung Shui, yesterday (January 2). Upon testing by AFCD staff, two of the samples were found to be positive for the ASF virus. The AFCD has immediately suspended transportation of any pigs from the farm concerned until further notice according to the contingency plan on ASF. The AFCD is arranging culling of all pigs, totalling over 400 on the farm concerned, for the sake of prudence."
He further said, "Positive cases should be seriously and promptly handled as the effect of ASF is very lethal to pigs. If the spread is not contained, a large number of pigs will die and hence seriously impact pig farmers and the pig-rearing industry. AFCD staff immediately notified all local pig farmers of this incident and reminded them to alert the AFCD immediately if any abnormal health condition is observed in pigs. In addition, the AFCD has arranged staff to inspect the seven pig farms within three kilometres of the index farm and collect pig samples for ASF testing. For the sake of prudence, the AFCD has been suspending movements of pigs on those seven pig farms until further notice. No reports of abnormalities from pig farms outside the three-kilometre zone have been received so far.
AFCD staff are conducting visits in phases to all local licensed pig farms to ensure biosecurity measures have been properly implemented and will continue its close surveillance to detect pigs with abnormalities and whether a farm is infected as early as possible. Surveillance of activities of wild pigs in the vicinity of the index farm has also been stepped up. Moreover, the AFCD is maintaining close contact with pig farmers via text message groups, keeping them informed of the latest situation of ASF and ways to prevent the infection of pigs."
Although Vietnam announced the development of a commercially available ASF vaccine last summer, the World Organization for Animal Health (WOAH) has yet to endorse its use, but they did issue a warning last October about the risks of using `sub-standard vaccines.'
While agricultural diseases don't get as much attention from the press and the public as those that can infect humans, they can still have an enormous impact on both the economy, and a nation's food security.
Which is why the USDA maintains an emergency response system for a myriad of imported disease threats, including ASF (see FAD PReP Materials and References).
