Bad sex from food poisoning

I have a particular interest in food poisoning. I admit there is something unhealthy about my fascination but there it is. One of the more interesting ones is ciguatera fish poisoning, and CDC has just reported an unusual cluster from North Carolina. Ciguatera fish poisoning (CFP) happens when a carnivorous fish higher in the food chain (e.g., barracuda, amberjack, red snapper, grouper) eats a smaller plant eating species that itself has dined on a large dinoflagellate called Gambierdiscus, commonly found around coral reefs in the Caribbean and in the Pacific. These little guys have a toxin that is converted to another toxin that interferes with the transport of sodium through cell membranes. In fact the toxin, called ciguatoxin, is the most potent sodium channel toxin known. It's not related to spoilage of the fish and isn't destroyed by cooking. The only way to prevent it is not to eat fish from Gambierdiscus infested reefs. If you do eat ciguatera toxin containing fish, attack rates can be as high as 80% or 90%. One of the unusual and characteristic features of ciguatera poisoning is the reversal of the sensations of heat and cold. In this case, there was an additional unusual feature. Bad sex:

On June 28, 2007, a woman and her husband (the index couple), both aged 31 years, were treated at a hospital emergency department for illness that developed within 24 hours after eating amberjack fish purchased from a local fish market and cooked at their home. Diagnoses of CFP were based on symptoms of mild diarrhea 4--12 hours after eating fish, followed by reversal of hot and cold sensation, abnormal skin sensations, and other neurologic symptoms within 24 hours. Both patients improved after treatment with intravenous mannitol, a long-standing treatment for CFP neurologic symptoms. Upon notification, investigators from the Food and Drug Protection Division of the North Carolina Department of Agriculture and Consumer Services contacted the fish market that sold the amberjack filets and discovered that seven of eight persons at a local dinner party also had become ill after eating amberjack from the same shipment. The one person who did not become ill was a young child who did not eat any fish.

[snip]

For three persons, symptoms reappeared or worsened after alcohol consumption. Six of seven sexually active patients (two males and four females) also reported painful intercourse as a symptom. Both males described painful ejaculation with intercourse. One male stated that ejaculation was painful during the course of 1 week; the duration of the second male's genitourinary symptoms was not reported. All four females described having a burning sensation during intercourse and 15 minutes to 3 hours after intercourse. Two females reported that burning sensations associated with intercourse continued for 1 month. Severity of illness could not be related to the amount of amberjack consumed nor to the incubation period.

Symptoms (i.e., abnormal skin sensations, itching, fatigue, or altered heat-cold sensation) lasted at least 1 month in all nine patients, but cleared within 6 months in six of the patients. Abnormal skin sensations persisted for 6--12 months in one of the nine patients; 1 year after onset of their CFP illnesses, two of the nine patients were still experiencing occasional symptoms of abnormal skin sensations, and one of those two was easily fatigued. (CDC, Morbidity and Mortality Weekly Reports [table cite omitted])

A Food and Drug Administratin (FDA) laboratory was able to detect ciguatera toxin in the fish meat. The levels are extremely low, less than a nanogram per gram of fish tissue (a nanogram is a billionth of a gram, and a gram is 1/28th of an ounce). One of the fascinating aspects of this cluster is the information it provided about the risk of breast feeding. One of the females was nursing her baby and became concerned that the toxin might pass into her breast milk. She had a frozen sample of her breast milk from before eating the fish and afterward. She learned on the internet that breast milk is a possible vehicle but she continued to breast feed her 8 month old, with no apparent ill effects on the baby. The FDA laboratory was unable to detect any ciguatera toxin in breast milk samples taken 1, 2 and 5 days after eating the fish. As far as I know this is the only solid evidence about the risks of breast feeding after ciguatera toxin poisoning.

The report of painful intercourse is an unusual feature of this cluster, although the MMWR cites one paper reporting "sexual transmission of ciguatoxin," (Lange WR, Lipkin KM, Yang GC. Can ciguatera be a sexually transmitted disease? Clin Toxicol 1989;27:193--7). This was a case where a male with ciguatera fish poisoning experienced painful ejaculation and his partner also experienced painful intercourse, although she had not been poisoned. The clear implication was that the ciguatoxin was present in the semen. In the new cluster both partners had been poisoned so we don't know if the symptoms were the result of ciguatoxin in semen only or was the result of the commonly reported neurological symptoms characteristic of the syndrome. While not unprecedented, painful intercourse is not considered a consequence of ciguatera fish poisoning.

One of the other nasty things about this is the persistence of symptoms for a long time after the acute episode. Three people in this cluster continued to have symptoms for as long as 6 months. While CFP is not exceptionally rare -- it's estimated there are 50,000 cases a year worldwide -- it is usually confined to tropical and sub-tropical regions. As sea waters are becoming warmer, affected states are also more northward than previously and North Carolina is now host to some ciguatera contaminated fish (the amberjack in this case, however, was from Georgia). CFP is becoming one of the most common of the fish associated food poisonings.

So when hot sex you were looking forward to turns cold and painful, just blame it on dinner.