NEWS SCAN: Anthrax cleanup cost, susceptibility to anthrax toxin, C diff tracking

Feb 8, 2012

Anthrax letter attacks led to $320 million in cleanup costs
A study of how much it cost to decontaminate buildings affected by the 2001 anthrax letters put the price tag at about $320 million, according to a report yesterday in Biosecurity and Bioterrorism. The researchers, from Concordia University in Montreal, calculated the figure by compiling a list of affected structures and analyzing the decontamination procedures for each type of building. Their total includes the cost of sampling and worker relocation. One of their key sources was decontamination contracting data from the Government Accountability Office. They found that testing was done at 26 buildings and remediation at seven. Six corporate offices were also contaminated. Two of the most costly remediation projects occurred at large postal distribution centers that required total fumigation because of aerosolized anthrax spores. The authors suggest that the lack of a single agency to manage the cleanup likely led to cost overruns and slowed decontamination, and they noted that a shortage of data makes it difficult to compare expenditures with the cost of policy responses. They said draft decontamination guidelines from the Department of Homeland Security help address uncertainties, but questions remain about decontaminating large outdoor spaces.
Feb 7 Biosecur Bioterror abstract

Genetic study finds varied susceptibility to anthrax toxin
Humans vary in their sensitivity to anthrax toxin, according to a genetic study from Stanford University researchers that appeared in the Feb 6 issue of Proceedings of the National Academy of Sciences. Their discovery came from an analysis of lymphocytic blastoid cells from 234 people of African, European, and Asian ancestry who were part of a HapMap Project. The genetic variation involved capillary morphogenesis gene 2 (CMG-2), which encodes a host membrane protein that the anthrax toxin can exploit as a receptor. Researchers found that sensitivity varied by a factor of 250 in 99% of the cohort and was an inherited trait that correlated with the abundance of CMG-2 messenger RNA in cells. The authors suggest that testing human cell populations may reveal clues about the effects of genetic variation on infectious disease susceptibility.
Feb 6 PNAS abstract

C difficile genotyping shows limited links to sick hospital patients
A study of Clostridium difficile found in stool samples found fewer than expected numbers linked to hospital patients with known infections, a finding that may have implications for hospital infection control practices, researchers reported yesterday in PLoS Medicine. The British research group tested 30,000 stool samples from almost 15,000 patients, finding that 1,282 were positive for C difficile. Genotyping studies found 69 types of C diff. When they linked the findings to clinical information, the authors found that most (66%) were not related to known cases and that only 23% shared the same type as a hospital ward patient that was known to be infected. The high number of infections that didn't appear to involve ward-based transmission suggests that current interventions may be missing possible targets, and a better understanding of transmission routes and reservoirs is needed to develop other strategies for curbing the spread of C difficile, the report says. In an accompanying editorial, two experts, Stephan Harbath, MD, from the University of Geneva Hospitals and Medical School in Switzerland and Matthew Samore, MD, from the University of Utah School of Medicine, noted that the new findings don't address clinical questions, such as quantifying the benefits of blocking C difficile transmission in symptomatic patients and the disease burden from patients who enter the hospital already infected. They suggest more research is needed.
Feb 7 PLoS Med abstract
Feb 7 EurekAlert press release
In other C difficile developments, a study conducted at 86 sites in Europe, the United States, and Canada found that oral fidamoxicin was similar to vancomycin in efficacy and safety, according to findings published today in Lancet Infectious Diseases. The drug was approved in the European Union and the United States last year for the treatment of C difficile infections. The findings confirmed an earlier phase 3 study that was conducted in the United States and Canada.
Feb 8 Lancet Infect Dis abstract

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