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Swine CAFOs & novel H1N1 flu: separating facts from fears.

Schmidt CW - Environ. Health Perspect. (2009)

View Article: PubMed Central - PubMed

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Caused by a strain of H1N1 influenza virus, which is normally found in pigs, the flu now known as novel H1N1 has so far been less severe than regular seasonal flu in terms of deaths and hospitalizations... The facilities emit a piercing odor that can be detected up to 6 miles from its source if not managed properly... Steven Wing, an associate professor of epidemiology at the University of North Carolina at Chapel Hill, reported in the March 2000 issue of EHP that CAFO odors can evoke emotional distress and headaches among local residents. “The biggest differences between CAFO-exposed communities and matched controls are found in quality-of-life measures,” he says of his findings. “These are indicated by how often local residents report that they can’t open windows or go outside even in nice weather. ” According to Wing, the ammonia-laden airborne emissions released by CAFOs are also linked to asthma, mucous membrane irritation, and other respiratory sysmptoms... When zoonotic flu viruses jump from species to species, they can pick up new mutations and reassort into novel strains that might be unrecognizable to both animal and human immune systems, Gray explains. “If we want to detect novel viruses from the human–animal interface, then we also need to study the workers,” he emphasizes... The agency charged with ensuring worker safety is the Occupational Safety and Health Administration (OSHA)... When asked how OSHA regulates zoonotic disease risk at CAFOs, a spokesman at the agency said its purview applies exclusively to bloodborne pathogens via the Bloodborne Pathogens Standard (29 CFR 1910.1030), which excludes respiratory infections such as swine flu... A crucial question is whether other, potentially more lethal influenzas could emerge from CAFOs, assuming these facilities allow new strains to evolve with unprecedented speed and efficiency... By concentrating so many viruses in one place, he explains, CAFOs increase the frequency at which more dangerous strains might appear. “This is all a numbers game,” he says. “The more variants you’re exposed to, the more likely it is that you’ll be exposed to one with altered properties that allows for infection of a new host. ” Given that threat, the industry relies on biosecurity measures to prevent pathogens from getting into or out of CAFOs... The degree to which hog waste might be pathogenic is unknown... Echoing conclusions reached by others, Wing says there’s no evidence to suggest that communities living near CAFOs have elevated rates of infectious illness... Kelley Donham, a professor of occupational and environmental health at the University of Iowa College of Public Health, adds that influenza in particular doesn’t survive well in the environment. “It’s a respiratory virus,” he says. “It’s always looking for respiratory epithelial cells, so it doesn’t seem plausible to suggest that it could be transmitted through waste. ” Still, Donham says other zoonotic pathogens in hog waste—particularly bacterial agents including Salmonella, Leptospira, and some infectious strains of Escherichia coli—could travel downwind as spray aerosols and theoretically infect local populations... Extracting accurate information in this embattled context is challenging at best—or, some say, impossible... As with other complex topics, nearly every significant aspect of CAFO production can be viewed from multiple perspectives... But perhaps this much is clear: the current pandemic shows that viruses of animal origin can pose a substantial human health threat... And if CAFOs were to accelerate the evolution of these viruses, Gray says, then the public has a right to know how those viruses evolve and what steps can be taken to limit their spread. “If we find something new,” he says, “we need to heighten surveillance to track it—not sit on it and pretend nothing’s happening until the problem explodes. ”

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How Novel Influenza Strains Evolve
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f4-ehp-117-a394: How Novel Influenza Strains Evolve


Swine CAFOs & novel H1N1 flu: separating facts from fears.

Schmidt CW - Environ. Health Perspect. (2009)

How Novel Influenza Strains Evolve
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2737041&req=5

f4-ehp-117-a394: How Novel Influenza Strains Evolve

View Article: PubMed Central - PubMed

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Caused by a strain of H1N1 influenza virus, which is normally found in pigs, the flu now known as novel H1N1 has so far been less severe than regular seasonal flu in terms of deaths and hospitalizations... The facilities emit a piercing odor that can be detected up to 6 miles from its source if not managed properly... Steven Wing, an associate professor of epidemiology at the University of North Carolina at Chapel Hill, reported in the March 2000 issue of EHP that CAFO odors can evoke emotional distress and headaches among local residents. “The biggest differences between CAFO-exposed communities and matched controls are found in quality-of-life measures,” he says of his findings. “These are indicated by how often local residents report that they can’t open windows or go outside even in nice weather. ” According to Wing, the ammonia-laden airborne emissions released by CAFOs are also linked to asthma, mucous membrane irritation, and other respiratory sysmptoms... When zoonotic flu viruses jump from species to species, they can pick up new mutations and reassort into novel strains that might be unrecognizable to both animal and human immune systems, Gray explains. “If we want to detect novel viruses from the human–animal interface, then we also need to study the workers,” he emphasizes... The agency charged with ensuring worker safety is the Occupational Safety and Health Administration (OSHA)... When asked how OSHA regulates zoonotic disease risk at CAFOs, a spokesman at the agency said its purview applies exclusively to bloodborne pathogens via the Bloodborne Pathogens Standard (29 CFR 1910.1030), which excludes respiratory infections such as swine flu... A crucial question is whether other, potentially more lethal influenzas could emerge from CAFOs, assuming these facilities allow new strains to evolve with unprecedented speed and efficiency... By concentrating so many viruses in one place, he explains, CAFOs increase the frequency at which more dangerous strains might appear. “This is all a numbers game,” he says. “The more variants you’re exposed to, the more likely it is that you’ll be exposed to one with altered properties that allows for infection of a new host. ” Given that threat, the industry relies on biosecurity measures to prevent pathogens from getting into or out of CAFOs... The degree to which hog waste might be pathogenic is unknown... Echoing conclusions reached by others, Wing says there’s no evidence to suggest that communities living near CAFOs have elevated rates of infectious illness... Kelley Donham, a professor of occupational and environmental health at the University of Iowa College of Public Health, adds that influenza in particular doesn’t survive well in the environment. “It’s a respiratory virus,” he says. “It’s always looking for respiratory epithelial cells, so it doesn’t seem plausible to suggest that it could be transmitted through waste. ” Still, Donham says other zoonotic pathogens in hog waste—particularly bacterial agents including Salmonella, Leptospira, and some infectious strains of Escherichia coli—could travel downwind as spray aerosols and theoretically infect local populations... Extracting accurate information in this embattled context is challenging at best—or, some say, impossible... As with other complex topics, nearly every significant aspect of CAFO production can be viewed from multiple perspectives... But perhaps this much is clear: the current pandemic shows that viruses of animal origin can pose a substantial human health threat... And if CAFOs were to accelerate the evolution of these viruses, Gray says, then the public has a right to know how those viruses evolve and what steps can be taken to limit their spread. “If we find something new,” he says, “we need to heighten surveillance to track it—not sit on it and pretend nothing’s happening until the problem explodes. ”

Show MeSH
Related in: MedlinePlus