For large scale agri-business, nothing conjures feelings of dread like the emergence of a highly pathogenic strain of avian influenza, or an outbreak of FMD (Foot & Mouth Disease), as both threaten large segments of a region’s economy and food production, and neither are easy to eradicate.
Last January South Korea was hit by a new strain of avian flu – H5N8 – which spread to scores of farms across the nation and led to the culling of more than 10 million birds. Although the outbreak appeared to have been stamped out by May, last month (see Korea: Fears Of H5N8 Resurgence) a new outbreak was reported on a poultry farm in Daegu.
After a quiet month on the bird flu front, yesterday Korean media reported another outbreak of H5N8, this time in South Jeolla.
Avian influenza (AI) was confirmed yesterday at a duck farm in Korea, local officials said, just days after the government detected another instance of the potentially deadly foot-and-mouth disease.
The South Jeolla Livestock Sanitation Office said yesterday that a highly pathogenic strain of bird flu, H5N8, was discovered Friday at a duck farm in Hampyeong in the southwestern province. Upon official confirmation, approximately 42,000 ducks at the farm were immediately culled, officials said.
Although there is a decided seasonality to avian flu outbreaks (peaking in winter & spring), theses viruses can continue to circulate year-round. Areas where the H5N1 virus is particularly well entrenched – like Egypt & Indonesia – frequently report poultry outbreaks even in the heart of summer.
This is the first summer of H5N8, and thus far, the seasonal pattern of the virus appears to be consistent with what we’ve seen with H5N1 and H7N9.
Earlier this year, in EID Journal: Describing 3 Distinct H5N8 Reassortants In Korea – we saw a report on the continual evolution of the H5N8 virus. Like all flu viruses – H5N8 continues to mutate and adapt – meaning that the virus we see next fall, or next year, may not behave quite like the virus we have before us today.
Adding insult to injury, last week South Korea also reported their first FMD case in three years (see OIE: Foot & Mouth Disease In South Korea), setting off alarm bells, and putting the nation on alert for this hard to eradicate disease.
FMD is a highly contagious viral disease that primarily afflicts cloven-hoofed animals (including cattle, sheep, goats, pigs, deer, etc.). Caused by a picornavirus, it has no relation to HFMD, which is a childhood disease in humans caused by a number of non-polio enteroviruses.
While there were hopes that the discover of FMD last week at a pig farm represented an isolated incident, today another outbreak has been reported on a pig farm 70 kilometers distant from the first report. This from AFP.
POSTED: 28 Jul 2014 17:56
South Korea on Monday (July 28) reported its second case of foot-and-mouth disease in less than a week. An official confirmed the case in a pig farm in North Gyeongsang province, but played down the threat.
During the 2010-2011 FMD outbreak in South Korea, roughly 3.5 million animals were destroyed (151,425 cattle, 3,318,299 pigs, 8,071 goats, and 2,728 deer) and buried at more than four thousand locations around the country (EID Journal Control of Foot-and-Mouth Disease during 2010–2011 Epidemic, South Korea).
While culling was a huge part of the control operation, South Korea also imported a Serotype 0 vaccine and instituted a `vaccinate to live’ policy, as described in the EID dispatch above:
According to national policy, culling began in November 2010 for all animals on farms with infected animals. Once vaccination was expanded nationwide in mid-January 2011, a vaccination-to-live policy was implemented; that is, vaccinated animals on farms with infected animals were culled only if the outbreak began within 2 weeks after vaccination but not if the outbreak began >2 weeks after vaccination.
As a result, a high percentage of South Korea’s livestock are vaccinated against the currently detected FMD serotype, which ought to help contain its spread.
Although the 7 serotypes of FMD are found all over the world, the United States has not seen an outbreak since 1929.
OIE Disease Outbreak Map – Current FMD
A 2013 Homeland Security report (see A World Free of one of the Most Virulent Animal Diseases?) on the creation of a new, (single sero-type) non-live virus vaccine for FMD, warns that the costs of an outbreak in this country could exceed $50 billion.
While definite progress, with 7 sero-types, and more than 60 known subtypes, the world remains a long way from eliminating this scourge.