Deadly Dinners: Mushrooms, Botulism, and Salmonella 


By Andy Oppenheimer

Andy Oppenheimer discusses recent cases of poisoning by mushrooms and the risk that foodborne toxins such as Clostridium botulinum and Salmonella could be used in bioterrorism.

The term “CBRN” has long been synonymous with weapons of mass destruction. Chemical, biological, radiological, and nuclear weapons, as well as their components and delivery systems, are usually viewed as likely to cause mass casualties.  

However, other definitions are more borderline. Incidents involving a biotoxin like ricin, for example, rarely cause mass injuries and casualties but are still included in the CBRN pantheon of potential lethality, and are termed as “non-conventional weapons”. 

A Lethal Lunch Down Under 

This kind of incident, ordinarily involving a cytotoxic substance causing a small number of casualties, recently hit the headlines in Australia and beyond. In early November an Australian woman, Erin Patterson, was charged on three counts of murder and five counts of attempted murder.  

What aroused the extraordinary media attention was that the three people who died had symptoms consistent with eating death cap mushrooms following a lunch of Beef Wellington, which contained mushrooms, cooked and served by the accused in Leongatha, Victoria, on July 29, 2023. Death cap mushrooms are responsible for 90% of all mushroom-related deaths.  

The fatalities included the accused’s former parents-in-law, as well as the former mother-in-law’s sister. Her husband remained critically ill in hospital for two months, but survived. Of added interest is that four of the attempted murder counts relate to incidents of alleged poisoning of the accused’s ex-husband, Simon Patterson, in 2021 and 2022. Mr. Patterson had been invited to the lethal lunch on July 29, but was unable to make it. 

The accused has claimed that she bought button mushrooms from a major supermarket chain and dried mushrooms from an Asian grocery store in Melbourne. The case comes to trial in May 2024. 

While such an incident is not related to nation-state or terrorist CBRN, as a criminal case it still warrants attention due to the suspected toxic materials involved. In any such case, the source must be traced, and outbreak types identified as natural, accidental, or deliberate. 

Death Caps 

Preliminary toxicology reports suggest that the victims consumed death cap mushrooms (Amanita phalloides), but at the time of writing in December 2023 this is yet to be confirmed. Death caps contain cytotoxins – amatoxins and phallotoxins – and are among the deadliest mushroom types found. 

A single bite on an aptly named death cap mushroom can be fatal. Severe gastrointestinal upset is followed by jaundice, kidney damage, and liver failure. There is no antidote and liver transplant is the only treatment. 

Mushrooms are a popular food – increasingly so since the rise of veganism – and in the case of magic mushrooms have long been picked and consumed for hallucinogenic intoxication. This type is sometimes misidentified by mushroom pickers and turn out to be death caps.

Amanita phalloides: the lethal deathcap mushroom, seen here in Piacenza, Italy, ©Wikimedia Commons

Mushroom Poisoning on the Rise 

Poisoning often occurs following mushroom picking and ingestion of toxic species – even when eaten along with edible ones – as well as poor cooking of ordinary mushrooms and contamination with bacteria or viruses. Another mushroom type implicated in rare poisoning cases is Russula subnigricans, which causes multi-organ failure.  

The increased consumption of toxic mushrooms has led to a rise in poisoning cases worldwide. As an example, in August 2023 the French Health Security Agency recorded more than 250 cases of mushroom poisoning – double the number recorded in France during the same month last year – and following a similar increase in 2022. 

The Russian Scientist Case 

More controversially, a month after the Australian poisoning case came to light, reports alleged that a Russian scientist had perished from mushroom poisoning.  

Prof. Vitaly Melnikov, who was the director of Russia’s Department of Rocket and Space Systems at the spacecraft manufacturer RSC Energia, died in hospital on August 31 at the age of 77 from kidney failure, reportedly from “severe poisoning” two weeks after he fell ill after eating “inedible” mushrooms.  

Circumstances surrounding the alleged poisoning are not clear. In one report in a Russian newspaper, Moskovskij Komsomolets, Melnikov’s family said he picked the mushrooms alone in a nearby forest outside Moscow – which he had done regularly with no problems.  

His death joined a long list of critics of the Putin regime who have died in suspicious – and varied – circumstances. Melnikov also worked with the Russian state space agency Roskosmos and was not a Putin critic; in his case it may have been as a result of national embarrassment. His death came weeks after Russia’s first lunar mission in 47 years failed when its unmanned spacecraft crashed on the Moon’s surface.

Russian Professor Vitaly Melnikov died in hospital on August 31 at the age of 77 after suspected mushroom poisoning, © Entropy Institute

Foodborne Toxins: Botulism 

A number of incidents have occurred where accidental and potentially lethal poisoning from food involved botulinum toxin (BoNT). Botulism is a serious neurological condition caused by the highly potent toxin – said to be 100 billion times more toxic than cyanide – produced by the bacterium Clostridium botulinum. It is more popularly known as a cosmetic treatment for facial wrinkles. 

Initial symptoms of foodborne botulism may appear from several hours to eight days following consumption. They include severe fatigue, weakness, vertigo, blurred vision, difficulty swallowing, opening the eyes, speaking, vomiting, diarrhoea, constipation, and abdominal swelling. Descending, flaccid paralysis then causes respiratory failure. Around 250 cases of infant botulism occur in the U.S. annually, but many more may be undiagnosed.  

Antitoxin is available exclusively from public health authorities but are only effective before the toxins enter the victim’s motor neurons. 

Inhalational botulism could result from aerosolization of BoNT, and iatrogenic botulism can result from injection of toxin. It is, however, most commonly found in poorly preserved or inadequately canned foods, or in home canning. C. botulinum forms a spore that survives standard cooking and food-processing measures. 

Canned tuna has been implicated in several cases in the U.S., including in March 1963 when three Detroit women were clinically diagnosed as victims of botulism following a meal of tuna fish salad sandwiches. Two died.  

The largest recorded outbreak of foodborne botulism in the U.K. occurred in June 1989 and was traced to cartons of contaminated hazelnut yoghurt. Of 27 patients affected, one died.

Photomicrograph of Clostridium botulinum bacteria. The nerve toxin it produces causes the rare but often fatal botulism, ©Wikimedia Commons

French Outbreak and Response 

More recently, in September 2023, French local public health authorities in Bordeaux and Ile-de-France identified 15 cases of suspected botulism, of which one died. The source of infection was homemade preserved sardines, on different dates, at a restaurant in Bordeaux.

  • Sept 11-14, 2023: Food and serum samples were shipped to the French National Reference Center for Anaerobic Bacteria and Botulism, Institute Pasteur, Paris. BoNT was confirmed in serum samples and in a food sample (sardines).
  • Local health authorities inspected the restaurant and all products prepared by the restaurant were recalled.
  • National health authorities issued risk communication advice to healthcare workers about symptomatology and treatment.
  • Information on cases reported among citizens from foreign countries was shared with relevant health authorities in those countries. 
BabyBIG® human antitoxin for the treatment of infant botulism, ©CDC/California Department of Public Health

Use in Bioterrorism 

Highly toxic microorganisms are more likely to cause accidental illness or death rather than be deployed as a malicious biological warfare agent. However, botulinum toxin could, nevertheless, be disseminated via aerosol or by contamination of water or food supplies, causing widespread casualties.  

In a paper published by the Indian Journal of Medical Research in 2010, it was asserted that, assuming an average weight of 70kg each of 5.6 billion people, only 39.2g of pure BoNT would be sufficient to wipe out humankind. Therefore, assuming a global population of 8.1 billion, only 56.7g of pure BoNT would be enough to do the same at the time of publication. 

The Japanese death cult Aum Shinrikyō attempted to use BoNT three times from April 1990 to March 1995 but failed. It is more likely that a deliberate attack would be an act of biocrime on a restaurant or other food outlet.  

The most notorious incident to date did not involve botulism or mushrooms, but deliberate contamination by Salmonella of salad bars at ten restaurants in The Dalles, Oregon, by followers of the Rajneeshee cult in late 1984. Some 751 people suffered food poisoning; 45 were hospitalized. While no fatalities occurred, this incident remains the single biggest recorded bioterrorist attack in U.S. history. 

Although poisoning from mushrooms and microorganisms is thankfully relatively rare, as with all outbreaks causing illness, injury, and fatalities, preparedness is vital. These non-conventional weapons represent unique challenges to healthcare professionals, but their ability to kill huge numbers of people should not be underestimated. 

Andy Oppenheimer is the author of IRA: The Bombs and the Bullets – A History of Deadly Ingenuity (2008) and a former editor of CBNW and Jane’s NBC Defense. He is a Member of the International Association of Bomb Technicians & Investigators and an Associate Member of the Institute of Explosives Engineers, and has written and lectured on CBRNe since 2002.  

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