February 10, 2000
REVISED DRAFT RISK ASSESSMENT AVAILABLE; COMMENT PERIOD EXTENDED
In December 1999, CVM posted a draft quantitative risk assessment on the Center's Home Page on the Internet. The draft risk assessment evaluates the human health impact of fluoroquinolone resistant Campylobacter associated with the consumption of chicken.
This draft risk assessment was discussed at the FDA Center for Veterinary Medicine Workshop on Risk Assessment and the Establishment of Thresholds held in Rockville MD, on December 9-10, 1999. At the Workshop, CVM stated that a revised version of the draft Risk Assessment would be placed on the Center's Home Page to improve consistency of the document and correct typographical errors. A revised draft now is on the CVM Home Page .
The risk assessment is still in draft form. CVM would appreciate receiving any data that would improve the Center's quantification of any of the model parameters or assumptions. Interested persons should submit written comments on the draft risk assessment to the Dockets Management Branch (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Room 1061, Rockville, MD 20852. Comments should be identified with Docket Number 98D-0969. The deadline for receipt of comments has been extended to February 24, 2000.
Changes in the revised draft document are listed below:
A section titled "Using the Model to Manage the Human Health Impact" was added to the Introduction.
A footnote describing the denominator for the proportion of physicians requesting stools from patients with bloody diarrhea was included in Section 2.2. The model will be updated with receipt of additional data from the physician’s survey increasing the denominator from 18 to 180. The larger data set will be used in the final report and will have little impact on the results except to slightly decrease model output uncertainty.
Section 3.5: A footnote describes a recognized logical inconsistency in this parameter estimate (prh) that has not been corrected in this model. CVM has removed cases of campylobacteriosis attributable to sources other than chicken. Because resistance was predominantly attributed to chickens, after removal of travelers and prior fluoroquinolone use, the remaining "chicken associated cases" should reflect the level of resistance restricted to the chicken associated cases. This correction will be made in the final revision.
In addition to the above revisions, two versions of the working Risk Assessment Model (Excel and @Risk versions) have been placed on the revised draft risk assessment page . These working models will allow modelers to either determine the risk using data sources other than those used in the model or allow use of different methods or distributions to model the risk.
Individuals interested in the working Risk Assessment Model who do not have access to the Internet may receive a computer disk with this information by calling or writing CVM's Communications Staff at FDA/Center for Veterinary Medicine, HFV-12, 7500 Standish Place, Rockville, MD 20855, 301-594-1755.
Questions about the risk assessment may be addressed to Dr. Nicholas Weber, FDA/Center for Veterinary Medicine, 7500 Standish Place, HFV-151, Rockville, MD 20855, 301-827-6986, e-mail: nweber@cvm.fda.gov.
Issued by:
FDA, Center for Veterinary Medicine,
Communications Staff, HFV-12
7519 Standish Place, Rockville, MD 20855
Telephone: (240) 276-9300 FAX: (240) 276-9115
Internet Web Site: http://www.fda.gov/cvm