- According to the assessment of the rapid diagnostic tests,
there would not be "false positives" as mentioned in the previous
CWD (Wisconsin) update.
- The statement below indicates more chance for false negatives.
In other words, a deer who has contracted CWD might not test positive.
- This information then clarifies the article posted yesterday
regarding the increase in CWD cases in Wisconsin and indicates that many
more CWD ARE BEING identified with the tests. In other words, CWD is on
the rise dramatically.
- Patricia Doyle
- A ProMED-mail post
- ProMED-mail, a program of the
- International Society for Infectious Diseases
- Date: 18 Mar 2004
- From: Geoffrey Fosgate
- There seems to be a minor error concerning the interpretation
of the diagnostic properties of the IDEXX HerdChek for CWD. A sensitivity
of 98.8 percent and specificity of 100 percent would suggest no false-positive
results, but a small proportion of false-negative results.
- Perfect specificity would be a little unusual given the
nature of the detection platform. I tend to be cautious when interpreting
sensitivity and specificity estimates independent of information concerning
the sample size, sample selection, and gold standard determination.
- Geoffrey T. Fosgate DVM, PhD, DACVPM
- Assistant Professor, Epidemiology
- Department of Veterinary Anatomy and Public Health
- College of Veterinary Medicine
- Texas A&M University
- College Station, TX 77843-4458
- [ProMED-mail appreciates Dr. Fosgate's correction and
agrees with his
- caution regarding the manufacturer's claim of perfect
- Patricia A. Doyle, PhD
- Please visit my "Emerging Diseases" message
board at: http://www.clickitnews.com/ubbthreads/postlist.php?Cat=&Board=emergingdiseases
- Zhan le Devlesa tai sastimasa
- Go with God and in Good Health