What made 50 people so sick?

The author, serving as a county health officer, had to find out—fast—and alert the public.

By David L. White, MD
Family Practitioner/Eugene, OR

Voltaire once quipped that common sense is not so common. This was dramatized for me one summer day when I served as the health officer of Oregon's Lane County, which includes the college town of Eugene (pop. 120,000). I oversaw the venereal disease clinic, family planning program, maternal and child health program, and others. In addition, I was the leader of the communicable disease team, which was responsible for controlling the spread of contagion in the county.

At 3 pm, the health department began to receive calls from Eugene residents who had been stricken with abdominal cramps, nausea, and diarrhea. Calls about such symptoms weren't unusual; we got a few each day. Our standard procedure was to take down the caller's information and wait to see whether others phoned with the same complaints. This time, did they ever! Within an hour, we heard from more than 40 people with gastrointestinal problems. When you have a small population, that's cause for alarm.

I called an emergency meeting of the communicable disease team. Besides me, it included a nurse and the supervising sanitarian, whose staff ensured that local businesses didn't violate the health code. Normally, we dealt with measles outbreaks, syphilis in a migrant worker camp, food poisoning at a local eatery—things like that. But the speed and intensity with which the symptoms were spreading suggested something more urgent. Phone calls to the ERs at three local hospitals revealed no sudden surge of symptomatic patients, which was odd. Yet, by the time the team had assembled, more than 50 cases had been logged.

Our first task was to seek common denominators. Every call had been from a resident of Eugene, not an outlying community. So the epidemic was isolated. All the symptoms were similar and had occurred within the previous two hours, implying that this was a "common source" outbreak.

Next, we needed to collect food histories. With the help of public health nurses and sanitarians, we questioned the victims, asking about restaurants patronized, water drunk, medicines taken, and places visited. They had but a single thing in common: All had recently eaten prunes.

As it turned out, representatives of a well-known prune company had gone door to door in Eugene that morning, dispensing hermetically sealed foil bags of prunes. The packages were designed with doorknob-size holes, so if someone wasn't home, a bag could be left. Some of those bags had hung for hours in the summer sun. It was possible that the prunes had spoiled or spawned cultures of toxic bacteria.

Lab work, as every doctor knows, takes time. Meanwhile, I was faced with a community crisis. I wasn't sure whether to wait for conclusive results or go public right away, warning people against eating prunes found hanging on their doorknobs.

In Portland, the Oregon state health department met in emergency session and decided on immediate, full disclosure. A press conference was hastily arranged. Three local TV stations, two newspapers, and a myriad of local radio stations were invited to send reporters. At 5:30 pm, before a sea of outstretched microphones and pens scribbling on notepads, I pronounced the prune samples under suspicion and warned people not to eat them until further notice. The next day, my picture, brandishing a bag full of suspects, appeared in one of the local papers. The caption decreed: "Prunes the problem."

That evening, sanitarians and public health nurses visited some 20 victims, as well as their neighbors, retrieving opened and unopened bags of the alleged culprits. We notified the Centers for Disease Control and Prevention in Atlanta. We collected stool samples from many diarrhea sufferers. Curiously, though, no one got really sick. Nobody suffered from fever, or chills, or bleeding—merely diarrhea, nausea, and abdominal cramps. Still, we ordered cultures and toxicology tests performed on prunes from sealed and unsealed bags, as well as on the stool samples.

The next morning, as the outbreak continued to spread, our switchboard lights twinkled urgently with calls from fresh victims. By then, most health department resources had been shifted to the prune problem. The prune company was deeply concerned. At 10 am, its attorney appeared in my office. I assured him that the condemnatory newspaper caption was a hastily drawn conclusion by reporters that I hadn't encouraged, and that we wouldn't pillory his client's product—unless the lab reports confirmed that such vilification was warranted. But I added that I had no choice but to counsel prudence in prune consumption, at least for now.

To my surprise, the epidemic subsided almost as abruptly as it had appeared, and our stricken citizens were able to leave their bathrooms and return to normal life. No one died—or even required hospitalization. Forty-eight hours after the outbreak exploded, the lab technicians rendered their verdict: Sun-baked or not, prunes in hermetically sealed foil bags were virtually indestructible. The prune cultures were negative. The stool cultures revealed only normal flora. No toxic material was found on the prunes or in the people who consumed them.

So the communicable disease team proceeded to perform some epidemiological calculations. First, we counted the number of prunes in unopened bags, which ranged from 19 to 21. We then counted the remaining prunes in the open bags we'd retrieved. That number averaged eight. Therefore, the average victim must have popped about a dozen prunes in fairly rapid succession.

Well, people can't eat that many prunes without suffering consequences. Not for nothing are prunes prescribed for irregularity. What goes in one end inevitably comes out the other, and the greater the quantity of the former, the greater the violence of the latter.

That evening, at the behest of the prune company counsel, I held another press conference to exonerate the suspects. To dramatize our findings, I opened one of the packages in question and, blinded by camera flashes, sampled the contents—not a dozen, mind you, merely one—to underscore that, while an ounce of prevention is worth a pound of cure, going overboard has dangers of its own.

 

David White. What made 50 people so sick?. Medical Economics 2001;8:135.