Toxic squash syndrome, honey intoxication and fish poisoning in Washington state

Posted on July 18, 2011 by


By Carol M. Ostrom

Just when there’s a lull in major foodborne illness reports, and you feel like it’s safe to eat, along come toxic squash syndrome, honey intoxication and scombroid fish poisoning, according to the Seattle Times.

Public health and poison-control experts have identified three cases in which eaters were temporarily felled by unusual foodborne toxins in King County over the past few months. All the victims recovered from the toxins, which are rare, but weird and interesting.

The suspected case of what health officials termed toxic squash syndrome began after a woman who ate a tiny amount of cooked acorn squash — butter and brown sugar, usually yum — developed severe intestinal discomfort.

The squash tasted very bitter, which stopped her from eating more. The bitter taste, in fact, was the telltale clue: Plants in the family Cucurbitaceae (squash, pumpkins, zucchini, cucumbers, melons and gourds) produce a bitter toxin — cucurbitacin — as a defense mechanism against insects, said Dr. Tao Sheng Kwan-Gett in the latest issue of “Epi-Log,” a communicable disease and epidemiology newsletter produced by Public Health — Seattle & King County.

Sometimes, for various reasons, a few squashes or other plants will overproduce cucurbitacin. In this case, the offending squash was traced to a local farm, wrote Kwan-Gett, but no other complaints about it came in to health officials, the Washington Department of Agriculture, the Washington Poison Center or the grocery store where the squash made its way into the woman’s shopping cart.

In the case of suspected honey intoxication, it’s likely that insects were to blame again, this time more directly. The trouble began about an hour after a man ate two or three tablespoons of vanilla-infused honey he bought at a local farmer’s market. The man, who experienced vomiting and intestinal difficulties lasting about 24 hours, alerted Poison Control, the farmer’s market and the honey producer, Kwan-Gett wrote.

His symptoms led to the conclusion that his troubles were likely caused by grayanotoxin poisoning, also known as rhododendron poisoning and “mad honey intoxication.” The problem is typically caused by bees that snacked on rhodies, picking up the natural neurotoxin.

A sample of the honey, tested by the agriculture department, didn’t turn up the toxin, but not all types were detectable by the test, Kwan-Gett wrote. He noted that honey from small producers is more likely to contain the toxin, because commercial processing mixes large amounts of honey from many different sources.

Fatalities from grayanotoxin are rare, but it can cause arrhythmias, sweating, dizziness, excessive salivation, vomiting and diarrhea.

Ahi tuna was the culprit in the scombroid fish poisoning case, which began when a woman ate a tuna salad at a local seafood restaurant in May. About 30 minutes later, she felt hot and dizzy, then flushed and short of breath. Friends took her to an emergency room, where she was diagnosed with scombroid poisoning, given IV fluids and an antihistamine.

The doctor called the restaurant, which pulled the tuna from the menu and contacted Public Health. The FDA collected the tuna for testing and results are pending, Kwan-Gett wrote.

Dr. Jeff Duchin, chief of communicable-disease control for Public Health — Seattle & King County, said that unlike the first two toxins, scombroid fish poisoning is relatively common, occurring when certain types of fish — tuna, mackerel, mahi mahi and marlin, among others — are not kept cold.

The amino acid histidine, which occurs naturally in the fish tissue, is converted at warm temperatures into histamine, typically causing a burning sensation in the mouth, a rash and a drop in blood pressure, along with sometimes serious gastrointestinal symptoms.

In most cases, these toxins won’t produce long-lasting illness but are a subject of fascination for those who study foodborne illness.

“It’s cool stuff,” Duchin said. “Unusual stuff is cool.”

Posted in: Family safety