A group of prisoners from Utah were admitted to hospital after getting severe botulism from potato-based wine brewed behind bars.
Eight prisoners were admitted to hospital with trouble swallowing, double vision, difficulty speaking and weakness around 54 hours after drinking the home brew known as pruno.
The incident took place in 2011, but a study into the poisoning has now been published in the Annals of Emergency Medicine.
Botulism is an extremely rare and sometimes fatal paralytic illness that can be caused by consuming food contaminated with the botulinum toxin.
Megan Fix, from the Division of Emergency Medicine at the University of Utah in Salt Lake City, said: "Evidently the incorporation of an old baked potato in the pruno recipe allowed botulism to develop.
"The patient who cooked the wine had cooked this recipe approximately 20 times previously without a potato, but his decision to experiment sickened him and seven other inmates.
"The patients' initial reluctance to confess their consumption of pruno could have been deadly since botulism requires fast intervention."
CDC 'only source' for anti-toxin
The amount of wine each prisoner consumed varied widely, with some saying they had drunk more than two gallons. Three of the worst-affected patients had respiratory failure and had to be intubated.
Botulism caused by food is very rare, with around 20 cases recorded in the US every year.
US authorities hold stockpiles of botulism anti-toxin in case of a bioterrorism attack. Supplies are held by the Centres for Disease Control and Prevention and the process of obtaining the anti-toxin can be time consuming for this reason.
Experts studied the case to see how quickly the patients were treated because of the rarity of the outbreak. They were all treated within 12 hours of being admitted to hospital, the report said.
Fix said: "The CDC is the only source for botulism anti-toxin. However, there are a number of steps involved in obtaining it. The CDC recommends that emergency physicians treat patients first, if botulism is suspected, rather than waiting for a positive test. Therefore it's important to contact the CDC to obtain the anti-toxin based on clinical suspicion as we can't treat the disease without having the anti-toxin in hand."
The largest ever botulism outbreak in the US took place in 1977, when 59 individuals were poisoned after eating at the same Mexican restaurant and had eaten a hot sauce made from home-canned jalapeno peppers.