Monday, November 18, 2019

African Swine Fever's (ASF) Other Impacts; Pharmaceuticals, Bushmeat, and Food Insecurity

http://www.fao.org/docs/eims/upload/298761/an321e00.pdf
Credit FAO















#14,530


African Swine Fever (ASF) and Classical Swine Fever (CSF) continue to spread globally, and endanger anywhere from 25% to 50% of the world's pig supply.
Already, it has been estimated that half of China's pigs have been lost to ASF and much of their food supply has been contaminated (see Australia: Agriculture Minister - 49% Of September Seized Pork Tests Positive for ASF).
While China only reports (163 ASF outbreaks detected in 32 Provinces / Autonomous Regions / Municipalities / Special Administrative Region, about 1,192,000 pigs have been culled - cite Nov 14th FAO Update), outside experts put the real number 200 times higher.  
Although ASF and CSF pose no direct threat to human health, the loss of 200 million pigs has driven the price of pork sky high in China, and in some regions pork - even if you can afford it - is increasingly difficult to obtain. 
With 1.3 billion hungry mouths to feed, China is highly dependent upon its agricultural production. Between animal diseases like FMD, PED, PRRS, avian flu, and ASF, increasing droughts, heavy floods, and the arrival of the crop devastating Fall Armyworm (Spodoptera frugiperda) last spring (see China: Update: Fall Armyworm Now in 15 of China’s Provinces), China's food supply is under pressure.
As we've discussed previously, food insecurity - whether due to agricultural diseases, floods, droughts, pests, or other causes - can foment societal discord, up to and including revolution (see Iran: Bird Flu, Food Insecurity & Civil Unrest).
There are also concerns that a number of our critical pharmaceuticals are derived (at least, in part) from Chinese pigs - including Heparin - which has been in short supply for over a year (see Reuters report Congress seeks briefing on potential threat to U.S. heparin supply).
Heparin isn't the only pharmaceutical we get from pigs, but it is the most critical one.  And as ASF spreads out of China and across Asia, the world's pig supply will only decline further.
And we've already seen ASF turn up in Vietnam, North and South Korea, the Philippines, Laos, Cambodia, Myanmar, and Timor.   We are also watching reports of (as yet) unidentified pig die offs in Indonesia (see Indonesia: Media Reports Of Positive ASF Test Results In North Sumatra).

ASF is also spreading across large swaths of Russia, and continues to make inroads into Eastern and Central Europe (see UK DEFRA: Updated Outbreak Assessment (#02) African Swine fever in Europe.)
African Swine Fever is a juggernaut that appears unstoppable, at least until an effective vaccine can be developed.
Meanwhile hungry people are going to find ways to find meat protein, even it it means relying more on bushmeat.  While that can be devastating to the wild animal population (including endangered species), it can also serve as an easy conduit for zoonotic diseases to spillover into the human population.

Every year we see outbreaks of Monkeypox, Lassa Fever, and sometimes even Ebola in Africa, many of which are believed tied to the hunting, processing, and consumption of bushmeat.  This from the FAO Bushmeat Sourcebook.

What are the links between bushmeat and human diseases?

Hunting and bushmeat consumption entail some risks for emergence of wildlife-related diseases that can be transmitted from animals to humans, also commonly called ‘zoonoses’. It is estimated that approximately 60% of all human pathogens are zoonotic, with some 75% emerging from wildlife. Over one billion cases of human zoonotic disease are estimated to occur annually.

The risk of contracting a disease depends on several factors but may occur even in mosaic landscapes of farms and fragmented forests where human–wildlife interaction is generally indirect or incidental. The lack of personal protection or hygiene during killing, handling and butchering is thought to be the main route of infection. While the process of curing/cooking the meat generally reduces the risk, it also requires consideration.
      (Continue . . . )


In 2002, the SARS Coronavirus swept across China, and emerged on the world stage, infecting thousands.  While the exact origins of the virus and spillover are still not known, it appears to have come from the `wild flavor' craze for exotic meats in Southern China early in the last decade.

From the WHO:
SARS (Severe Acute Respiratory Syndrome)
Cause
SARS coronavirus (SARS-CoV) – virus identified in 2003. SARS-CoV is thought to be an animal virus from an as-yet-uncertain animal reservoir, perhaps bats, that spread to other animals (civet cats) and first infected humans in the Guangdong province of southern China in 2002.
China has banned (repeatedly) the consumption of civet cats, and other `wild flavor' or endangered animals, since the SARS epidemic, but the practice continues (see Despite Crackdown, `Wild Flavor’ Trade Continues In China).

Although surveillance and reporting on spillover events is spotty at best, we see scattered reports of human anthrax infection, strep suis (see Tiết Canh - An Incredibly Bat Idea, and most recently plague (see China: Inner Mongolia Reports Another Plague Case) linked to animal contact nearly every year out of Asia. 

And wildlife surveillance programs have shown there are a number of dangerous pathogens carried by bats (and potentially other bushmeat species) in the region.
Emerg. Microbes & Infect.: Novel Coronaviruses In Least Horseshoe Bats In Southwestern China 
PNAS: SARS-like WIV1-CoV Poised For Human Emergence

Sci Rpts: Avian & Human Influenza Compatible Receptor Cells In Little Brown Bats

Study: Hotspots For Bat To Human Disease Transmission

In 2005, the CDC’s EID Journal carried a perspective article on the dangers of bushmeat hunting by Nathan D. Wolfe, Peter Daszak, A. Marm Kilpatrick, and Donald S. Burke.
Bushmeat Hunting, Deforestation, and Prediction of Zoonotic Disease
It’s a terrific article,and the events since then with Ebola and Monkeypox in Africa have only made it more relevant.

Whether the recent reports of plague in Mongolia (last May), and Inner Mongolia over the past week, have anything to do with the ASF induced pork shortage is unknown.
But at least three of theses cases have been linked to bushmeat. 
While bushmeat has always been part of the diet in some parts of Asia, it is likely as ASF spreads - and more people across Asia face increased food insecurity - the amount of bushmeat that will be hunted, processed and consumed will increase.
And that, unfortunately, increases the chances of seeing a new zoonotic spillover, either from an old scourge like anthrax or rabies, or perhaps something new, like an emerging Coronavirus. 
Human health and animal health are all intertwined, and even though ASF doesn't directly infect humans, its impact on our health and well being may prove to be far greater than we appreciate.