Bird Flu Factories: How Industry Backed Science Favors Big Poultry and Ignores Danger

Rob Wallace January 31, 2017

"Intensive husbandry," in this case raising barns of thousands of poultry in packed homogeneous monoculture, is also referred to as "factory farming"—an industrial agribusiness production model that aims to maximize yields through various (often troubling) means.

Mul­ti­ple out­breaks of dead­ly H5 bird flu are dec­i­mat­ing poul­try across Europe, Asia and the Mid­dle East. The epi­dem­ic, mov­ing across Eura­sia in waves, fol­lows an erup­tion of H5N2 here in the Unit­ed States in 2015. All the new strains — H5N2, H5N3, H5N5, H5N6, H5N8, and H5N9, togeth­er called H5Nx — are descen­dants of the H5N1 sub­type that first emerged in Chi­na in 1997 and, since 2003, has killed 452 people.

Big Poul­try and its col­lab­o­ra­tors in gov­ern­ment are blam­ing wild water­fowl, which act as reser­voirs for many influen­za strains, for the new poul­try out­breaks. For instance, research under the aegis of Uni­ver­si­ty of Min­neso­ta Pro­fes­sor Car­ol Car­dona, who holds the indus­try-fund­ed Pomeroy Chair in Avian Health, claims that cli­mate change is dri­ving shifts in wild water­fowl ecol­o­gy and there­fore in the influen­za to which indus­tri­al poul­try here in Min­neso­ta are now exposed.

Con­trary to the industry’s claim, how­ev­er, exhaus­tive sam­pling con­duct­ed by state ornithol­o­gists found no H5N2 in wild water­fowl in Min­neso­ta. Yet Cardona’s team con­tin­ues to search for H5N2 in Spring 2015 sam­ples. Why? Sim­ply because it claims the virus must be there. The absence of evi­dence is treat­ed as no bar­ri­er to an expe­di­ent assump­tion about the nature of the out­break that favors the poul­try industry.

Blam­ing water­fowl is based on anoth­er fal­la­cy. Even if a search for H5N2 in water­fowl proved suc­cess­ful, what would it show? How would the pres­ence of H5N2 in water­fowl here in Min­neso­ta explain the dam­age the out­break has caused to indus­tri­al turkey and chick­en egg lay­ers here in the Mid­west in 2015 or across Eura­sia today?

The industry’s line of research omits address­ing why mul­ti­ple influen­za strains, includ­ing H5N2 and many of the oth­er new H5Nx strains, devel­op a dead­li­ness in its poul­try that isn’t found in most water­fowl. Indeed, no cas­es of high­ly path­o­gen­ic flu in wild water­fowl were record­ed any­where before 2005. Dead­ly flu in water­fowl has since been dis­cov­ered only as col­lat­er­al blow­back from out­breaks on farms.

As agri­cul­tur­al pro­duc­tion turns wet­lands into farm­land, migrat­ing water­fowl that have tra­di­tion­al­ly vis­it­ed wet­lands along their fly­ways have switched to feed­ing on grain on indus­tri­al farms. That is, the expand­ing inter­face between water­fowl and inten­sive poul­try pro­duc­tion isn’t caused exclu­sive­ly by cli­mat­ic changes, as the Car­dona team sug­gests, but by the actions of the indus­tri­al agri­cul­tur­al sec­tor itself.

Focus­ing on wild water­fowl and cli­mate change shifts scruti­ny from an indus­tri­al mod­el of poul­try pro­duc­tion that a grow­ing sci­en­tif­ic lit­er­a­ture indi­cates is itself a poten­tial­ly cat­a­stroph­ic pub­lic health dan­ger. Math­e­mat­i­cal mod­els of pathogen evo­lu­tion — reviewed here and here—show that inten­sive hus­bandry (rais­ing barns of thou­sands of poul­try in packed homo­ge­neous mono­cul­ture) offers much food for flu (and oth­er pathogens), spurring the evo­lu­tion of explo­sive deadliness.

The mod­els infer that a con­tin­u­al sup­ply of cramped-in genet­ic clones removes a cap on how dead­ly influen­za can evolve. With one new batch of birds after anoth­er every six weeks, thou­sands of immuno­log­i­cal­ly weak clones are always avail­able. The most vir­u­lent bird flu can be select­ed for, dec­i­mat­ing fowl pop­u­la­tions with­out run­ning out of new hosts to infect. The now dead­lier flu rou­tine­ly spills back out among local small­hold­er flocks and wild water­fowl. But indus­tri­al sci­en­tists blame the result­ing poul­try and water­fowl deaths as the cause of the outbreak.

Now new research is show­ing that the broad­er envi­ron­men­tal fac­tors, on which Cardona’s team is bank­ing as an expla­na­tion, like­ly had at best only mar­gin­al effect on the emer­gence of the new H5 influen­zas. In a peer-reviewed paper recent­ly pub­lished in eLIFE, a team led by Bel­gian spa­tial ecol­o­gist Mar­ius Gilbert intro­duced mod­els explain­ing the dif­fer­ence in spa­tial dis­tri­b­u­tions in influen­za out­breaks between the H5N1 sub­type and its daugh­ter H5Nx. Gilbert’s team showed that mod­els includ­ing pop­u­lar eco-cli­mat­ic vari­ables, such as land sur­face tem­per­a­ture, open water and veg­e­ta­tion, added lit­tle in explana­to­ry value.

Instead, the study demon­strates, it’s the com­bi­na­tion of host species that best explained the dis­tri­b­u­tion of outbreaks.

FIG­URE 1. MEAN REL­A­TIVE CON­TRI­BU­TIONS (%) ± STAN­DARD DEVI­A­TION OF DIF­FER­ENT SETS OF PRE­DIC­TOR VARI­ABLES FOR REGRES­SION TREE MOD­ELS FOR HIGH­LY PATH­O­GEN­IC AVIAN INFLUEN­ZA H5N1 (IN BLUE) AND H5NX CLADE 2.3.4.4 (IN RED). THE REL­A­TIVE CON­TRI­BU­TION IS A MEA­SURE OF THE REL­A­TIVE IMPOR­TANCE OF EACH PRE­DIC­TOR VARI­ABLE INCLUD­ED IN A REGRES­SION MOD­EL TO COM­PUTE THE MOD­EL PRE­DIC­TION. FUR­THER INFOR­MA­TION CAN BE FOUND HERE. (REPRINT­ED UNDER CRE­ATIVE COM­MONS ATTRI­BU­TION 4.0 INTERNATIONAL.)

As shown in Fig­ure 1, Gilbert’s team inferred the rel­a­tive con­tri­bu­tions the var­i­ous vari­ables made in explain­ing the glob­al spa­tial dis­tri­b­u­tions of old school H5N1 (blue) and new­bie H5Nx (red). We see that, yes, duck den­si­ty (DuDnLg) is a major con­trib­u­tor to both kinds of bird flu — although less so for H5Nx — but we should keep in mind that ducks are also raised as poul­try in inten­sive con­di­tions in many Euro­pean and Asian countries.

The head­line news here is that the H5 virus shift­ed from exten­sive chick­en pro­duc­tion (ChDnL­gExt) char­ac­ter­is­tic of most­ly small­hold­er pro­duc­tion to inten­sive chick­en pro­duc­tion (ChDNL­gInt), urban­ized human pop­u­la­tions (HpDnLg), and man­aged hor­ti­cul­ture (CultVeg). This means that the new strains now appear to be adapt­ed to indus­tri­al poul­try pro­duc­tion near urban centers.

FIG­URE 2. PRE­DICT­ED PROB­A­BIL­I­TY OF OCCUR­RENCE OF HIGH­LY PATH­O­GEN­IC H5N1 (TOP) AND OF H5NX CLADE 2.3.4.4 (BOT­TOM). THE DASHED BLACK LINE REP­RE­SENTS A BUFFER AROUND THE OCCUR­RENCE DATA FOR THE HPAI H5N1 AND H5NX CLADE 2.3.4.4 PRE­DIC­TIONS, COR­RE­SPOND­ING TO AN AREA FROM WHICH PSEU­DO-ABSENCES WERE SELECT­ED. THE CIR­CLE INSET SHOWS THE PRE­DIC­TION OBTAINED WHEN THE EFFECT OF THE VARI­ABLE ISCHI­NA, A VARI­ABLE TO ACCOUNT FOR THE EFFECT OF MASS VAC­CI­NA­TION OF POUL­TRY IN CHI­NA, WAS REMOVED. FUR­THER INFOR­MA­TION CAN BE FOUND HERE. (REPRINT­ED UNDER CRE­ATIVE COM­MONS ATTRI­BU­TION 4.0 INTERNATIONAL.)

As shown in Fig­ure 2, the Gilbert team glob­al­ly mapped the result­ing shift in influenza’s envi­ron­men­tal niche (the com­bi­na­tion of fac­tors sup­port­ing out­breaks) show­ing already doc­u­ment­ed hot spots for H5N1 (top) and H5Nx (bot­tom). As report­ed in the press, H5Nx is shown spread­ing in the U.S., Europe, Chi­na, and South Korea, among oth­er hot zones.

But the maps also show areas in poten­tial dan­ger of the new virus, albeit under the con­straint of apply­ing data from the ear­ly stages of an ongo­ing out­break. Bangladesh, Indone­sia, Aus­tralia, parts of South Amer­i­ca, and, prophet­i­cal­ly it turns out, the Nile Delta, are in dan­ger of host­ing out­breaks, should H5Nx migrate there.

The H5Nx virus is evolv­ing to bet­ter infect poultry

H5Nx’s rise isn’t just a mat­ter of a shift in where the virus is spread­ing, how­ev­er. The new strains have also mol­e­c­u­lar­ly adjust­ed. That is, the virus is evolv­ing new attrib­ut­es fit for infect­ing poultry.

In anoth­er new paper, a team of virol­o­gists from Utrecht Uni­ver­si­ty and the Scripps Research Insti­tute show an evo­lu­tion in a par­tic­u­lar mol­e­cule called hemag­glu­tinin – the H of H5 – that the influen­za virus uses to enter host cells.

A rare amino acid sub­sti­tu­tion in the recep­tor-bind­ing part of the mol­e­cule per­mits the new H5Nx both broad­er and more effi­cient bind­ing to tar­get cells. The virus has switched from bind­ing specif­i­cal­ly to recep­tors in water­fowl intestines to expand­ing to recep­tors found in poul­try throats. That means the virus is able to infect a broad­er range of host species, now includ­ing the poul­try glob­al agribusi­ness rais­es by the billions.

The mol­e­c­u­lar changes may also account for why there is a rapid rise in so many new strains of H5Nx, which swap gene seg­ments by a process called reas­sort­ment. As the virus begins to evolve more effi­cient­ly to tar­get its hosts, new ver­sions of the neu­raminidase pro­tein — the N in Nx — are appar­ent­ly being swapped in and out of the var­i­ous strains of H5Nx. How much virus is shed as a result dur­ing an infec­tion and the rapid­i­ty of dis­ease pro­gres­sion may also be affected.

For­tu­nate­ly, the Utrecht team found no adap­ta­tion to mam­malian recep­tors. So it seems no sus­tained trans­mis­sion of the virus among humans is like­ly. But the researchers only test­ed H5N8 in this study and human cas­es of H5N6 have already been doc­u­ment­ed in Chi­na. As H5Nx diver­si­fies and adapts to poul­try that tens of thou­sands of human han­dlers care for and process every day, the like­li­hood of a dead­ly human-spe­cif­ic flu emerg­ing increases.

Indus­try-fund­ed research is ignor­ing alarm­ing trends

The imme­di­ate take-home is that we have here diver­gent eco­log­i­cal and evo­lu­tion­ary analy­ses con­verg­ing upon the con­clu­sion that the new H5Nx are increas­ing­ly influen­zas adapt­ed to inten­sive­ly raised poul­try. That is, a grow­ing lit­er­a­ture of scrupu­lous­ly doc­u­ment­ed sci­ence is show­ing alarm­ing trends that are beyond the con­trol of agribusi­ness-fund­ed research.

These find­ings are in stark con­trast to the rosy nar­ra­tive pre­sent­ed by extreme­ly well-paid researchers backed by Big Poul­try in what the Uni­ver­si­ty of Min­neso­ta describes as the Sil­i­con Val­ley of food.” Those teams con­tin­ue to blame any­thing and any­one for bird flu oth­er than the eco­nom­ic mod­el at the heart of indus­tri­al poul­try production.

Farm­ers around the world, and the pop­u­la­tions they feed, deserve bet­ter. Grow­ers are bear­ing the eco­nom­ic costs of a mod­el of pro­duc­tion that sup­ports pathogens dead­ly to poul­try and poten­tial­ly dan­ger­ous to humans. The new research show­ing a new­ly adapt­ed influen­za must be heed­ed and adopt­ed for a fun­da­men­tal change in pub­lic pol­i­cy. Safer mod­els of poul­try pro­duc­tion now being devel­oped here in Min­neso­ta and around the world must be sup­port­ed before the next dead­ly pan­dem­ic sweeps the globe.

Indus­tri­al Pro­duc­tion of Poul­try Gives Rise to Dead­ly Strains of Bird Flu H5Nx was orig­i­nal­ly pub­lished on the Think For­ward” Blog of the Insti­tute for Agri­cul­ture and Trade Pol­i­cy and is repost­ed on Rur­al Amer­i­ca In These Times with per­mis­sion from Inde​pen​dentScience​News​.org. To learn more about this sub­ject, check out Rob Wal­lace’s new book Big Farms Make Big Flu: Dis­patch­es on Infec­tious Dis­ease, Agribusi­ness, and the Nature of Sci­ence. (Cov­er Image: ama​zon​.com)

[If you like what you’ve read, help us spread the word. Like” Rur­al Amer­i­ca In These Times on Face­book. Click on the Like Page” but­ton below the bear on the upper right of your screen. Also, fol­low RAITT on Twit­ter @RuralAmericaITT]
Rob Wal­lace received a Ph.D. in biol­o­gy at the CUNY Grad­u­ate Cen­ter, and did post-doc­tor­ate work at the Uni­ver­si­ty of Cal­i­for­nia, Irvine, with Wal­ter Fitch, a founder of mol­e­c­u­lar phy­loge­ny. He lives in St. Paul, Min­neso­ta, where he is both a Vis­it­ing Schol­ar at the Insti­tute for Glob­al Stud­ies, Uni­ver­si­ty of Min­neso­ta, and a deli clerk at a local sand­wich shop. He is co-author of Farm­ing Human Pathogens: Eco­log­i­cal Resilience and Evo­lu­tion­ary Process (Springer) and blogs at Farm­ing Pathogens’ — a blog about dis­ease in a world of our own making.
Limited Time:

SUBSCRIBE TO IN THESE TIMES MAGAZINE FOR JUST $1 A MONTH