British scientists recently discovered that the gene responsible for mad cow disease can lie dormant many years, which could create a second wave of disease.
Scientists had thought only 40 percent of the population was at risk for vCJD, the human equivalent of the mad cow infection. They now believe tens of thousands more people could be at risk if they consumed diseased meat in the 1980s and 1990s, the Scotsman reported.
A dormant infection was recently found in someone with the MV genotype that accounts for half the population. Now two other dormant infections have been discovered in the W genotype, meaning virtually everyone can be a carrier.
Professor James Ironside, of the National CJD Surveillance Unit at Edinburgh University, says it is possible incubation periods are very, very long. Blood transfusions and surgery could then allow the disease to spread indefinitely.
Microbiologist Professor Hugh Pennington said it was a case of waiting and seeing what might happen because no one really knows.
Copyright 2006 by United Press International