News in brief - Dec. 22/29, 2003

Virtual colonoscopy as polyp detector - Legislation could aid transplant access - West Nile: The conquering virus

Virtual colonoscopy as polyp detector

CT virtual colonoscopy using a three-dimensional approach to detect polyps did as well as, and in some cases even a bit better than, traditional optical colonoscopy, according to a study published in the Dec. 1 issue of the New England Journal of Medicine.

The sensitivity of virtual colonoscopy was 93.8% for polyps at least 10mm in diameter, 93.9% for polyps 8mm in diameter and 88.7% for polyps at least 6 mm in diameter. Optical colonoscopy detected 87.5%, 91.5% and 92.3% of polyps respectively. A total of 1,233 asymptomatic adults underwent virtual and optical colonoscopies on the same day for the comparison study.

While patients still face the unpleasant process of clearing out their colons before the virtual colonoscopy, there is no need for sedation, and the small danger of perforation of the colon is eliminated. However, if polyps are found, an optical colonoscopy would still be needed to remove them.

Everyone older than 50 is urged to be screened for colon cancer, and colonoscopy is recognized as the most sensitive and specific test for detecting precancerous polyps. However, some balk at scheduling the invasive procedure, and the hope is that the promise of a quick once-over with a CT scanner may lure more people in for screenings.

Legislation could aid transplant access

A Senate bill and a move by the Organ Procurement and Transplantation Network are intended to improve access to donated organs and make some progress on whittling down the list of 80,000 patients awaiting transplants.

The Senate passed legislation that would provide travel subsidies for living organ donors, create grant programs to increase organ donations and place organ donation coordinators in hospitals. The legislation was sponsored by Majority Leader Bill Frist, MD, (R, Tenn.), a transplant surgeon. The House currently has no companion legislation.

OPTN and the United Network for Organ Sharing recently launched a pilot study to assess the impact of beginning the waiting time for a kidney transplant at the time a candidate first begins dialysis or meets a standard medical definition of kidney failure.

The study is intended to improve transplant access, particularly among ethnic minorities and economically disadvantaged people on dialysis who may not be immediately evaluated for a kidney transplant. Currently, waiting time begins when a transplant center evaluates and accepts a transplant candidate, but some people do not undergo an evaluation until months or years after beginning dialysis. Minority and disadvantaged patients often experience greater difficulty obtaining access to transplantation.

West Nile: The conquering virus

Alexander the Great ruled Macedonia and evaded death when conquering the vast Persian empire. But West Nile virus may have felled the young ruler, according to an article published in the December issue of Emerging Infectious Diseases.

Alexander died in Babylon, an area near present day Baghdad, in 323 B.C. at age 32 after a two-week bout of fever. Speculation as to the cause of his death has ranged from poisoning to assassination to any number of infectious diseases.

However, Virginia State Epidemiologist John Marr, MD, and Charles Calisher, PhD, professor of microbiology at Colorado State University in Fort Collins, took note of the writing of Plutarch and have made the case that encephalitis caused by the West Nile virus dealt the fatal blow.

A flock of ravens exhibiting unusual behavior began dying just as Alexander entered Babylon, Plutarch had related. The behavior of the birds is reminiscent of avian illness and death that preceded the recognition of West Nile virus in the United States, note Drs. Marr and Calisher.

"It is possible," they write, "in the 3rd century B.C., disease caused by West Nile virus arrived in Mesopotamia for the first time in recorded history, killing indigenous birds and an occasional human and causing only incidental febrile illnesses in many others."