Toxin troubles —
The aim was to slow digestion, but it instead led to life-threatening paralysis.
– Mar 16, 2023 9:17 pm UTC
Enlarge / Micrograph of Clostridium botulinum.
Health officials in Europe are warning of an outbreak of botulism linked to botched weight-loss procedures carried out in Turkey that aimed to paralyze stomach muscles to reduce appetite. So far, authorities have identified 67 cases—53 in Turkey, 12 in Germany, and one each in Austria and Switzerland.
Botulism is a life-threatening neuroparalytic condition caused by the botulinum toxin, which is made by the bacterial species Clostridium botulinum. There are several forms of botulism, but in this outbreak, the cases are a form called iatrogenic botulism, which occurs when too much toxin is injected during medical procedures. Iatrogenic botulism is associated with generalized muscle weakness, drooping eyes, difficulty swallowing, and difficulty breathing. The cases in the outbreak have ranged from mild to severe, with a number of people ending up in intensive care, the European Centre for Disease Prevention and Control (ECDC) reported.
The botulinum toxin is one of the most poisonous natural substances known; a dose of just 1 nanogram per kilogram weight is lethal. Nevertheless, it has been used for cosmetic purposes, such as smoothing facial wrinkles, and some therapeutic purposes, such as treating an overactive bladder and chronic migraine headaches.
It has also been used in the stomach for weight-loss purposes, though studies on this application have been mixed in terms of efficacy. The idea is that the toxin paralyzes stomach muscles, slowing down digestion and how quickly the stomach empties. This is intended to keep people feeling full longer, leading to reduced appetite for as long as the toxin’s effects last, which can be around three months. The injection is carried out using an endoscope, a tube-like device that is equipped with a syringe to inject the toxin directly into the stomach muscle after snaking down the mouth and throat.
But things go badly when too much botulism is injected, as appears to be the case in Turkey. Officials in Europe traced the cases in Germany, Austria, and Switzerland to a single clinic in Istanbul. The cases in Turkey also link to that clinic, except for three that were traced to a private hospital in Izmir, Turkey. The ECDC noted that European patients coordinated their risky medical tourism via a WhatsApp group.
In the past, such iatrogenic botulism clusters have been linked to counterfeit toxin products, as was the case in an outbreak in Egypt in 2017. Last August, the World Health Organization warned of counterfeit batches of a botulism toxin product called Dysport. The bad batches had been detected in several countries, including Turkey. But a Turkish investigation of the current outbreak found it involved legitimate, licensed products, though ones that were not approved for use in the stomach, the ECDC reported. Turkish authorities have reportedly suspended medical procedures at both the health facilities identified and have begun further investigations into the medical providers involved.
The patients with botulism, meanwhile, face a long, harrowing road. Recovery can take weeks to months. In the 2017 outbreak linked to a counterfeit product, patients took between six and 12 weeks to fully recover. Because iatrogenic botulism is relatively rare, the mortality rate is unclear. But food-borne botulism—caused by ingesting improperly preserved or canned foods that become contaminated with the toxin—has a fatality rate of between 5 and 10 percent, the ECDC noted.
Botulism treatment can involve mechanical ventilation in the case of respiratory failure, as well as doses of an antitoxin called heptavalent botulinum antitoxin (HBAT), which is made from horses. HBAT contains antibodies from horses that have been immunized with wee doses of botulinum toxin. HBAT antibodies work by binding to the toxin while it’s in the blood, before it can irreversibly bind to presynaptic nerve endings and lead to paralysis. As such, the antitoxin can only prevent further paralysis; it can’t reverse whatever paralysis has already occurred. Still, while current fatality rates are lower than 10 percent, before the development of antitoxin, the fatality rate was 50 percent, according to the US Centers for Disease Control and Prevention.
Horses are often used for such antibody-based therapies because their large body size means a large blood volume, which in turn means that a large amount of antibodies—or other valuable proteins—can be harvested. In the US, a single thoroughbred horse named First Flight was the sole source of botulism antitoxin serum from its initial development in the 1970s to the 1990s.
First Flight was a retired racehorse who briefly worked as a caisson horse in military funerals at Arlington National Cemetery before reportedly bolting with a general’s coffin. In 1978, at the age of 10, he was transferred to the US Army Medical Research Institute of Infectious Diseases at Fort Detrick, Maryland, where he became the country’s only living factory for botulism antitoxin while also establishing a reputation for his feisty personality. After giving nearly 16,000 liters of blood during the 1980s and 1990s, First Flight was retired. He died in his Fort Detrick paddock of natural causes at the ripe age of 31. His halter and lead are held at the Smithsonian National Museum of American History.