No Mad Cow at New Jersey Racetrack

Just when I thought we had successfully navigated past last winter's mad cow maelstrom, a New Jersey woman and the state's two U.S. senators have set a course for a new misadventure.

Private citizen (and amateur public health sleuth) Janet Skarbek (search) claims to have identified 13 deaths from the brain disorder Creutzfeldt-Jakob disease (search) (CJD) among people who worked or visited Cherry Hill, N.J.'s Garden State Racetrack (search) between 1988-1992. Skarbek began "investigating" the deaths after a colleague of her mother who worked at the racetrack died of CJD.

Seemingly adding wind to Skarbek's sails is the recent death of an elderly man, bringing the total number of CJD deaths in a two-county area of Northern New Jersey to five over the past 15 months. Only one CJD death would be expected to occur among those counties' residents in that timeframe, according to government health statistics.

Based on these alleged "facts," New Jersey Sens. Frank Lautenberg and Jon Corzine are pressing the Centers for Disease Control and Prevention to determine whether this "cluster" of deaths was caused by eating mad cow-tainted meat. Had Sens. Lautenberg and Corzine given the matter more serious consideration rather than as an opportunity for political grandstanding, they would have discovered that the matter has been investigated and there is no link with mad cow.

First, none of the deaths even involve the disease specifically associated with mad cow. All the deaths at issue involve the form of Creutzfeldt-Jakob disease called sporadic CJD (search). But the human brain disorder supposedly associated with mad cow disease is a distinct and different condition called variant CJD (search). One of the deaths included in Skarbek's list is that of a 29-year-old woman who died in 2000. Physicians initially thought she was the first U.S. case of variant CJD, mostly because of her young age. Subsequent testing, however, at the CDC's National Prion Disease Pathology Center ruled out both variant CJD and sporadic CJD.

The most recent death, a 62-year-old man from Northern New Jersey, apparently has no link to the racetrack. There's simply no evidence that any of the deceased persons ate meat, at the racetrack or elsewhere, which was infected with tissue from diseased cattle.

Topping off this rapidly crumbling alleged link between mad cow and the 13 deaths is the fact that although the five CJD deaths exceed the rate expected for the two counties, it has not caused any notable aberration in the state's overall CJD death rate.

"New Jersey's incident rate is approximately eight per year, and thus there is no indication that we are exceeding the average case count per year," a New Jersey public health official told the United Press International. "In fact, over the last 25 years, there have been instances where the total number of cases topped out at around 14 per year," the official added.

It's quite possible, indeed likely, that the five deaths in the two-county area is simply a chance occurrence.

And we're not even talking about a disease associated with mad cow. Even the variant CJD deaths supposedly associated with mad cow that started occurring in the United Kingdom in the 1990s haven't developed in the sort of cluster claimed by Skarbek. There was one alleged cluster of five variant CJD deaths associated with the town of Queniborough (search). But as it turned out, only one of the cases actually lived in Queniborough. Of the other four deceased persons, one turned out not to be linked to the village at all; another was only a visitor; and two had moved away. It could be said that all four had at one time or another been in Queniborough, but that's a far cry from claiming a cluster in Queniborough. They may have all been in London at some point as well.

The alleged Queniborough cluster never amounted to much — no doubt because its originators were overeager to link variant CJD cases with some sort of commonality regardless of the facts. It's for that reason public health departments typically avoid investigating disease clusters.

The CDC investigated and reported on 108 so-called "cancer clusters" between 1961 and 1990, failing to link any of them with the various causes alleged. With the exception of typical food poisoning, disease clusters usually are unexplainable except that they occur by chance. State public health departments, accordingly, view most cluster investigations as wild goose chases.

Many have procedures in place to avoid tying up already scarce resources with pointless investigations. Those sensible procedures won't work, however, if politicians ignore facts and view cluster allegations as opportunities to campaign.