|
||||||||||||||||||
 |
From: TSS ()
November 17, 2006 A panel of scientists is expected today to release its review of whether the National Animal Disease Center improperly disposed of animal waste into Ames’ wastewater treatment system. The eight-person panel was asked to investigate claims that the federal research center failed to properly treat infectious waste before it was sent to the city’s wastewater treatment plant. The allegations were made this spring by two center employees who claimed they approached their supervisors with questions about the disposal of animal waste, including blood, feces, urine and other bodily fluids. The workers said they weren’t given sufficient answers and were threatened with a loss of funding for their jobs. Animal caretaker supervisor Richard Auwerda sent a letter on May 4 to the city, state veterinarian and state and federal agencies, saying he hoped the lab’s practices didn’t harm the environment or Ames residents. Auwerda and caretaker Timothy Gogerty claimed that the NADC’s procedures for destroying abnormally shaped proteins — called prions — appeared less stringent than the procedures at the nearby National Veterinary Services Laboratories. Prions are found in fatal diseases, including mad cow disease and chronic wasting disease. Auwerda and Gogerty said the rules also were less restrictive than those recommended by the U.S. Department of Health and Human Services, the Centers for Disease Control, and the National Institutes of Health. They also alleged the center wasn’t following its internal operating procedures for destroying prions. The Agricultural Research Service, which runs the lab, has denied that animal waste was improperly handled. Research service officials have said all the water used to wash away liquid animal waste was sterilized at 250 degrees Fahrenheit for 30 minutes — a method accepted by the World Health Organization. http://desmoinesregister.com/apps/pbcs.dll/article?AID=/20061117/NEWS/61117006 J Gen Virol 87 (2006), 3737-3740; DOI 10.1099/vir.0.82011-0 Infectious agent of sheep scrapie may persist in the environment for at least 16 years Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3 1 Institute for Experimental Pathology, University of Iceland, Keldur v/vesturlandsveg, IS-112 Reykjavík, Iceland In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheep-house that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years. http://www.healthtech.com/2007/tse/day1.asp Subject: Prions Adhere to Soil Minerals and Remain Infectious and Remain Infectious Joel A. Pedersen3,4* 1 Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 2 Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 3 Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 4 Department of Soil Science, University of Wisconsin Madison, Madison, Wisconsin, United States of America An unidentified environmental reservoir of infectivity contributes to the natural transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) in sheep, deer, and elk. Prion infectivity may enter soil environments via shedding from diseased animals and decomposition of infected carcasses. Burial of TSE-infected cattle, sheep, and deer as a means of disposal has resulted in unintentional introduction of prions into subsurface environments. We examined the potential for soil to serve as a TSE reservoir by studying the interaction of the diseaseassociated prion protein (PrPSc) with common soil minerals. In this study, we demonstrated substantial PrPSc adsorption to two clay minerals, quartz, and four whole soil samples. We quantified the PrPSc-binding capacities of each mineral. Furthermore, we observed that PrPSc desorbed from montmorillonite clay was cleaved at an N-terminal site and the interaction between PrPSc and Mte was strong, making desorption of the protein difficult. Despite cleavage and avid binding, PrPSc bound to Mte remained infectious. Results from our study suggest that PrPSc released into soil environments may be preserved in a bioavailable form, perpetuating prion disease epizootics and exposing other species to the infectious agent. Citation: Johnson CJ, Phillips KE, Schramm PT, McKenzie D, Aiken JM, et al. (2006) Prions adhere to soil minerals and remain infectious. PLoS Pathog 2(4): e32. DOI: 10.1371/ journal.ppat.0020032 snip... PLoS Pathogens | www.plospathogens.org April 2006 | Volume 2 | Issue 4 | e32 0007 Sorption of Prions to Soil > The calf was appropriately disposed of in a local http://www.prwatch.org/node/4624/print TSS
|
