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Biological incidents

Incidents where biological substances have been used offensively are relatively rare. In most cases, suspected attacks turn out to be hoaxes or accidental incidents. However, historically there have been a number of examples of weaponisation and application of biological substances. Below is a list of selected historical examples to illustrate the span of incidents:






Goal and application 


585 BC


The Greeks

Helleborus toxin

Contamination of water supply

Incapacitation of besieged city(1)



The Tatars 


Besieged city catapulted with carcasses

Presumably severe illness and multiple deaths. Contributed to an European epidemic(2)


Fort Pitt (today Pittsburg in the USA)

British army


Attack on Indians using contaminated

Possibly an outbreak of smallpox among native Americans(3)


USA, Argentina, Romania, Norway, Spain 


Anthrax, Glanders

Horses and mules being shipped to the Entente Powers were infected with anthrax or glanders

Unknown numbers of dead horses and mules(4)

1928-1992Soviet UnionCommunist regimeAnthrax, Smallpox, Marburg, Plague, TyphoidOffensive biological programmeSeveral accidents, including: Aralsk (1971)(5), Sverdlovsk (1979)(6)




Plague, Anthrax, Cholera, Typhoid

Brutal human experiments on civilians. Contamination of water supply and
airstrikes on cities

Hundreds of thousands died or became severely ill(7)

1940-1944Poland, GermanyPolish home army ZWZ-AKTyphoid, Anthrax, Dysentery, Glanders, Rabies, Cholera, Botulism, Staphylococcus aureusPrimary German troops, Nazi, SS and Gestapo, but also German civiliansAccording to Polish sources several thousand deaths and severe illness. German numbers are much lower(8)
1941-1944Soviet Union
(Ukraine and Belarus)
Soviet partisans and special forcesTyphoid and AconitinePrimary German occupation troops and Soviet collaboratorsAt least 100 died in Slavuta in Ukraine in 1942(9)
1975-1980RhodesiaGovernment forcesCholera, Botulinum toxin, anthraxEliminate communist insurgency movement171,990 cattle and 17,199 human cases of anthrax infection. 200 humans died from anthrax(10)


South Africa

The South African Apartheid regime

Anthrax, Plague, Cholera, Botulinum toxin, Ricin 

Anthrax was used for individual assassinations, and cholerae for contaminating water supplies in Namibia

Unknown number of fatalities and cases of illness among people(11)



Saddam Hussein’s dictatorship

Anthrax, Botulinum toxin, Ricin, Aflatoxin, Perfrigens toxin 

Offensive programme  

 No known cases were such weapons were used(13)


Dalles, OR, USA

Religious sect 


Food contamination (salad bars)

751 persons food poisoned(12)



Aum Shinrikyo

Anthrax (Non-pathogenic strain), Botulinum 

Aerosol dissemination in Tokyo 

No reported fatalities and probably no cases of illness(14)


Dallas , TX, USA



Food contamination (doughnuts)

12 food poisoned(15)





Anthrax letters sent to news agencies and senators via US Postal Service

22 cases of illness and 5 deaths(16)

2018GermanyIslamic StateRicinAttempt to build cluster bomb to disseminate ricinGerman police arrested the terrorists(17). According to German sources, the bomb could have killed more than 100 people(18)
2019TunisiaIslamic State?AnthraxLetters send to journalists, activists and politiciansThe letters were intercepted before they reached their intended victims(19)
2019ChinaCriminal gangsAfrican swine fever virus Drones were used to drop pork products contaminated with the virus on pig farmsUnknown, but presumably the attacks worsened an already existing outbreak of the virus in Chinese pig farms(20)



  1. Amanda Foreman: "The Ugly Arsenal of Poison and Pestilence". Wall Street Journal. September 20, 2013.
  2. Mark Wheelis: "Biological Warfare at the 1346 Siege of Caffa". Historical Review, volume 8, no. 9. September 2002.
  3. W. Seth Carus: "A Short History of Biological Warfare: From Pre-History to the 21st Century". CSWMD Occasional Paper 12. Page 7-9.
  4. Mark Wheelis: "Biological sabotage in World War I". Chapter in "Biological and Toxin Weapons". Editor Erhard Geissler and John Ellis van Courtland Moon. Oxford University Press, 2003. Page 35-62.
  5. Kristian Hveysel Bork: "Aralsk ’71 hændelsen". 2003.
  6. Kristian Hveysel Bork: "Sverdlovsk ulykken". 2003.
  7. Jeanne Guillemin: "Crossing the Normative Barrier: Japan's Biological Warfare in China in World War II". Chapter in "Biological Threats in the 21st Century". Editor Filippa Lentzos. Imperial College Press, 2016. Page 17-40.
  8. Robert Petersen: ”When a nation is being murdered” – The secret biological and chemical war against the Third Reich". Zeszyty Naukowe AON no. 2 (103), 2016.
  9. Alexander Gogun: "Stalin’s Commandos". I. B. Tauris, 2016. Page 134-135, 140-146.
  10. James M. Wilson, Walter Brediger, Tom Albright & Julie Smith-Gagen: "Reanalysis of the Anthrax Epidemic in Rhodesia, 1978-84". BioRxiv, May 17, 2016.
  11. Alistair Hair: "The South African Biological Warfare Program". Chapter in "Biological Threats in the 21st Century". Editor Filippa Lentzos. Imperial College Press, 2016. Page 137-158.
  12. W. Seth Carus: "A Short History of Biological Warfare: From Pre-History to the 21st Century". CSWMD Occasional Paper 12. Page 42.
  13. Tim Trevan: "The Iraqi Biological Warfare Program". Chapter in "Biological Threats in the 21st Century". Editor Filippa Lentzos. Imperial College Press, 2016. Page 113-129.
  14. Richard Danzig, Marc Sageman, Terrance Leighton, Lloyd Hough, Hidemi Yuki, Rui Kotani & Zachary M. Hosford: "Aum Shinrikyo - Insights Into How Terrorists Develop Biological and Chemical Weapons". Center for a New American Security, December 2012.
  15. Shellie A. Kolavic, Akiko Kimura, Shauna L. Simons; Laurence Slutsker, Suzanne Barth & Charles E. Haley: "Outbreak of Shigella dysenteriae Type 2 Among Laboratory Workers Due to Intentional Food Contamination". Journal of American Medical Association, Volume 278 Issue 5, August 6, 1997. Page 396-398.
  16. Jeanne Guillemin: "American Anthrax: Fear, Crime, and the Investigation of the Nation's Deadliest Bioterror Attack". Times Books, 2011.
  17. CBB: "Islamisk Stat og brug af ricin til terror". Notat. April 12, 2019.
  18. Clemens Schminke: "Terroranschlag geplant Gericht fällt Urteil im Rizin-Bomber-Prozess". Kölner Stadt-Anzeiger. March 2, 2020.
  19. "Anthrax toxin letters – Tunesia: (Tunis) Human targets, suspected, request for information". ProMED, March 4, 2019.
  20. Liu Zhen: "Chinese criminal gangs spreading African swine fever to force farmers to sell pigs cheaply so they can profit". South China Morning Post. December 14, 2019. & Min Zhang, Tom Daly: "Commercial pig farm in China jams drone signal to combat swine fever crooks". Reuters. December 20, 2019.