Table of Contents:



I. Storm Gathering

1. 1918

2. Master of Metamorphosis

3. H5N1

4. Playing Chicken

5. Worse Than 1918?

6. When, Not If

II. When Animal Viruses Attack

1. The Third Age

2. Man Made

3. Livestock Revolution

4. Tracing the Flight Path

5. One Flu Over the Chicken's Nest

6. Coming Home to Roost

7. Guarding the Henhouse

III. Pandemic Preparedness

1. Cooping Up Bird Flu

2. Race Against Time

3. Tamiflu

IV. Surviving the Pandemic

1. Don't Wing It

2. Our Health in Our Hands

3. Be Prepared

V. Preventing Future Pandemics

1. Tinderbox

2. Reining in the Pale Horse


References 1-3,199

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Battery caged hens from below

In intensive confinement production, crowding, stress, and filth go hand in hand in hand. The USDA points out that a single gram of manure (approximately the weight of a paper clip) from an infected chicken can contain “enough virus to infect 1 million birds.”1763 A 20,000-bird broiler flock produces more than a ton of droppings every day.1764

They are literally sitting in it. By the end of their lives, many of the birds can no longer stand. “The birds are bred for such size that their legs become so weak that they often cannot support the weight of their bodies,” explains a USDA poultry specialist. “They therefore spend much of the time squatting on the floor in the litter.”1765 That’s where they eat, sleep, and defecate. At just six weeks old, meat-type chickens are so heavy and the stress on their hips and legs so great that they spend more than three-quarters of their time lying in their own waste.1766 Leading industry consultant Temple Grandin writes: “Today’s poultry chicken has been bred to grow so rapidly that its legs can collapse under the weight of its ballooning body. It’s awful.”1767 By the time they are slaughtered, all of their carcasses will show evidence of gross fecal contamination.1768 Small wonder modern poultry products represent such prime carriers of foodborne illness,1769 especially since, unlike with cows and pigs, the skin can be eaten with the meat.1770

The putrefying feces generate several irritating chemicals, including hydrogen sulfide (the “rotten egg” gas), methane, and ammonia.1771 “Ammonia in a poultry house is nauseating to the caretaker, irritates the eyes, and affects the chickens,” states one poultry science textbook.1772 Given the extreme stocking density, the litter can get so saturated with excrement that birds may develop sores or “ammonia burns” on their skin, known as breast blisters, hock burns, and footpad dermatitis, all of which have become significantly more common and serious over the last 30 years.1773 The ammonia burns the birds’ eyes and lungs as well.

Studies have shown that high levels of ammonia increase the severity of respiratory disorders like pneumonia1774 in part by directly damaging the respiratory tract, predisposing them to infection.1775 A massive study involving millions of birds from nearly 100 commercial farms across multiple countries found that ammonia levels increased the excretion of the stress hormone corticosteroid, a potent immune depressant.1776

Besides the role chronic irritative stress plays, ammonia also directly suppresses the immune system. Ammonia gets absorbed into the birds’ bloodstreams, where it interferes with the action of individual white blood immune cells.1777 Although airborne aerosol spread of H5N1 remains relatively inefficient, even among birds,1778 the ammonia damage associated with intensive poultry production may facilitate the virus acquiring so-called pneumotropic, or “lung-seeking,” behavior.1779

The air within industrial broiler chicken sheds is thick with fecal dust, presumably making disease spread effortless for the influenza virus. Increased stocking density leads to high concentrations of aerial pollutants, which then leads to increased respiratory disease challenge to the birds’ immune systems.1780 In addition to fecal material, the airborne dust in such facilities has been found to contain bacteria, bacterial toxins, viruses, molds, nasal discharge, feather and skin debris, feed particles, and insect parts.1781 Poultry confinement buildings can average more than a million bacteria floating in every cubic yard of air.1782

In addition to adding to airway irritation, these dust particles clog up the birds’ lungs, overwhelming the lungs’ clearance mechanisms. Researchers demonstrated decades ago that exposing a chick to a normally harmless strain of E. coli in an environment clouded with dust or ammonia can cause disease.1783 The very air birds breathe in intensive confinement may predispose them to infection with influenza.

Every day, in every shed, another ton of droppings is dropped. In the United States, meat-type chickens are slaughtered at about 45 days and a new flock of chicks is brought in from the hatchery. Unbelievably, the broiler sheds may not be cleaned between flocks. So new hatchling chicks are placed directly on the tons of feces that have already been layered down, and the cycle continues. “European growers visiting U.S. production facilities inevitably find this practice shocking,” admits poultry specialist Frank Jones at the Department of Poultry Science at North Carolina State University.

Veterinary experts have also been critical of this practice. As specified in the journal of the World Organization for Animal Health, fecal waste should be removed from the shed before adding a new flock.1784 The UN Food and Agriculture Organization agrees the dirty litter should be removed.1785 Placing day-old chicks in sheds contaminated with “built-up” litter is said to expose the birds to “a wide range of poultry pathogens.”1786 The Advisory Committee on the Microbiological Safety of Food reported that the most significant source of Campylobacter infection in chickens—infection that goes on to sicken millions of Americans1787 —is “the environment of the industrial broiler house.”1788 The poultry industry suspects that “general farm hygiene could reduce the numbers [of Campylobacter bacteria-contaminated carcasses] by around 40%.” A “zero tolerance” policy is impractical, the industry emphasizes, “because it is impossible to achieve at reasonable cost….”1789 Leaving the caked layer of fecal material is another example of “least cost production,” not least risk.

Low-cost poultry housing means dirt floors.1790 Every time the shed is cleaned, some of the dirt is scraped up, eventually requiring replacement with more dirt. Concrete floors are easier to clean more frequently, but are more expensive. “We’re really locked into the system we’ve got,” Jones says. “It would cost dearly to change it now.”

In a specially commissioned feature on preventing disease to celebrate Poultry International’s 40-year publishing history, the trade magazine noted: “Replacing used litter between flocks is a standard practice worldwide, but it will not gain acceptance in the United States.” The investment would evidently not be worth the return. “[U]nless federal regulations force drastic changes,” the article concluded, “nothing spectacular should be expected.”1791