Last September - a little more than a month after China announced their first outbreak of African Swine Fever (ASF) - Japan announced the discovery of Classical Swine Fever (CSF) in Gifu Prefecture (see Japan: MAFF Confirms Classical Swine Fever Outbreak).
Often clinically indistinguishable from African Swine Fever (ASF), Classical Swine Fever is caused by a different virus (genus Pestivirus, family Flaviviridae).Both diseases are highly contagious, and can be economically devastating for pork producers, but neither disease is considered zoonotic threat. Japan had been one of only 35 countries that has been certified by the OIE as being free of the disease with their last outbreak reported in the early 1990s.
Over the first 6 months, Japan reported just 10 farms affected. But since early March we've seen an increase in outbreaks - albeit still limited to Gifu and Aichi Prefectures - with 14 farms infected over the past 10 weeks.
Details on the 24th farm affected come from this translated report from Japan's Ministry of Agriculture (MAFF).
Confirmation of suspected affected animals of swine fever in Gifu Prefecture, about (24 case was in Japan)
Ryowa first year May 25,
the Ministry of Agriculture, Forestry and Fisheries
Today, a suspected case of pig cholera has been confirmed at a farm in Yamagata, Gifu Prefecture, which is within 10 km of the wild boar positive confirmation point and has been monitored.
We will make every effort on preventive measures against this disease.
We would like cooperation to refrain strictly from coverage on the spot as there is a risk of causing the spread of this disease.
1. Outline of outbreak farm
Location: Yamagata City, Gifu Prefecture2. History
The feeding situation: 2,214 head
(1) Gifu Prefecture received a report from the farm on Friday, May 24 that the breeding pig was showing an abnormality, and conducted on-site inspections by livestock epidemiologists.
(2) On the same day, suspicion of hog cholera arose in the examination at the livestock health and hygiene center, so when a detailed examination was carried out, it was revealed today (Saturday, May 25) that it is a false case of hog cholera. did.
While farm-to-farm transmission has been documented in some of these outbreaks, the virus has been detected in hundreds of wild boar in the region (particularly in Gifu Prefecture), and they appear to be a major contributor to its spread.
The most recent OIE Summary (May 17th) reads:
Summary of the wild boar surveillance
- As of the 16th May, 1118 wild boars (210 dead and 908 captured) in Gifu prefecture have been tested and 408 (158 dead and 250 captured) were found to be positive for CSF virus (CSFV) by RT-PCR since 13th of September 2018.
- 296 wild boars (17 dead and 279 captured) in Aichi prefecture have been tested and 16 were found to be positive (2 dead and 16 captured) for CSFV by RT-PCR since 14th September 2018.
- Among the other prefectures, 295 wild boars (272 dead and 23 captured) in 40 prefectures were tested and all were found to be negative for CSFV by RT-PCR since the 14th September 2018.
- Note: Vaccination policy in Japan is that vaccination for domestic animals only is prohibited. Since 24th March 2019, oral vaccine (bait vaccine) have been applied to wild boars in selected area in Gifu and Aichi prefecture where CSF positive cases have been found in wild boars.