What is the history of Anthrax in America and other countries?

The first reports of anthrax in the U.S. were documented in 1868 when Dr. Silas Stone described eight patients with symptoms of anthrax. As the cause of symptoms was unknown, Stone referred to the condition as “malignant pustules.” All eight were linked to a factory processing animal hair in Massachusetts. Six of the eight had severe symptoms, and two died as a result, likely from meningitis. 

Multiple experiments on anthrax took place during the 19^th Century. While anthrax was never confirmed by culture, it was believed to be an organism capable of multiplying in the body, invading the bloodstream, and causing death by sepsis. In 1876, Robert Koch proved that Bacillus anthracis (B. anthracis) was responsible for anthrax and conducted animal experiments. He also discovered what environmental conditions were favorable to the anthrax spore’s survival and determined that certain pastures could be deadly to animals as spores could survive for decades in the soil. 

Louis Pasteur discovered that the remains of animals who had died from anthrax and were buried could still cause anthrax infections, and earthworms could carry anthrax spores to the surface. Pasteur also determined that B anthracis itself could cause anthrax and not a toxic substance produced by the bacterium, as some believed was the case. 

Inhalation anthrax was also recognized in the 19^th Century and was initially labeled as “woolsorters” disease, but also came to be known as Bradford disease after many cases occurred in the Bradford, England area. This disease was first seen in 1847 among British woolsorters working with alpaca hides from Peru and goat hairs from Asia Minor.   

In 1880, Bradford physician John H. Bell published a paper on this disease and described where affected woolsorters would rapidly die from their symptoms. He also discovered B anthracis in the victims’ blood and concluded that this was the cause of the disease.   

Rules regarding the care and treatment of the raw materials were put forth, and in 1897, these rules, known as the Bradford rules, became law. Between 1899 and 1907, there were 447 cases of anthrax and 120 deaths from all forms of anthrax. 

In 1905, the Anthrax Investigation Board was formed and added a bacteriologist, F.W. Eurich. Eurich spent years investigating anthrax and methods to eliminate the bacterium from animal hairs. After many experiments, Eurich discovered that two percent formaldehyde at 100 degrees F for 30 minutes would kill the spores. 

Great Britain enacted the Anthrax Prevention Act in 1919, which required animal hairs considered high-risk for anthrax to be decontaminated before being imported. No additional cases of inhalation anthrax related to the British hair and wool industry were reported after 1929. 

Anthrax was also reported as a health problem in the U.S. during this time and linked to the handling of animal hides. In 1916, an outbreak occurred in Massachusetts, affecting 25 people, of which 23 had direct contact with animal hides. Twenty of those were directly linked to a single source of hides shipped from China. 

In 1919, the U.S. Public Health Service issued a warning about anthrax and shaving brushes. In this report, public health officials warned that the recommended sterilization processes were not being followed, which had resulted in cases of facial anthrax. During World War I, the supply chain disruption was blamed for the rise in cases, as animal hairs used in the production of the brushes were not being properly disinfected. Horsehair and pig bristles imported into the U.S. from Russia, China, and Japan for use in shaving brushes were previously sent to France or Germany and disinfected before shipping to the U.S.; however, due to the war, direct shipments from Asian countries were now commonly occurring. As few brushes were labeled with any mark to trace their origins, public health officials could not pinpoint where the source of the anthrax-containing brushes were from. 

Between 1919 and 1924, 61 anthrax cases and 19 deaths were reported in New York City, and shaving brushes accounted for just over half of the cases. Except for three cases, all sources of anthrax were confirmed as being related to the manufacturing, handling, transporting, or usage of contaminated items made from animal byproducts. 

In the U.S., between 1919 and September 1, 1925, 632 anthrax cases and 177 deaths were documented from 33 reporting states. When the sources of anthrax were known, most were connected to the leather industry. Anthrax related to shaving brushes was reported as declining and was attributed to the increasing awareness of the dangers. 

In the early 20th century, anthrax treatment consisted of anthrax antiserum given locally or intravenously. Surgical excision of the anthrax pustule was also used but often found to be ineffective or harmful.  Physicians treating anthrax found that many cases of cutaneous anthrax would resolve on their own and surgical interventions often caused septicemia, which was frequently fatal. 

Between 1945 and 1951, there were 372 reported anthrax cases, with over 300 cases occurring in the seven northeastern states and linked to industrial exposures. Twenty-nine cases were associated with agriculture exposures and were reported as cutaneous anthrax. Additionally, there were 658 outbreaks of anthrax among animals between 1945 and 1950, and an estimated 8,505 died as a result. 

In 1951 and 1952, numerous anthrax outbreaks among animals were reported and linked to bone meal. Most cases occurred in Indiana, Ohio, and other Midwestern states. There were no human cases associated with this outbreak. The use of penicillin and anthrax antiserum assisted in halting the outbreak. 

Despite an increase in animal anthrax cases, there were fewer human cases and no reports of transmission from animals to humans through meat or milk. Antibiotics were considered effective against anthrax, and public health officials believed that the use of antibiotics could potentially replace antiserum. 

By the 1950s, cases and deaths from anthrax had dropped significantly in the U.S.; however, disease rates remained high in most countries globally. Countries with higher rates were noted to have poor sanitation practices, and health officials suspected that rates were likely even higher than what was being reported.   There were 45 reported anthrax cases in the U.S. in 1953. 

The first known outbreak of inhalation anthrax in the U.S. occurred in 1957 at a goat hair factory in New Hampshire. Five individuals developed inhalation anthrax within ten weeks. Four cases were fatal.  In total, for 1957, there were 26 reported anthrax cases. 

In 1960, 23 anthrax cases were reported. All cases were cutaneous and none fatal. Twenty were associated with industrial exposures, with 15 reported from one South Carolina mill that had recently begun processing imported goat hair. This increased from 1959 when 15 cases were reported, and from 1958, which had 17 reported cases. 

Anthrax cases continued to decline, and during the 1960s, there were an average of five cases per year and a total of two deaths.    By 1980, an average of two cases occurred yearly.  Rates continued to decrease, and between 1981 and 2000, there were only six reported anthrax cases. 

In the fall of 2001, 22 cases and five deaths from anthrax occurred due to an anthrax bioterrorism attack. Additionally, one separate anthrax case was reported in 2001 and traced to an anthrax-infected animal.   

Between 2002 to 2020, nine human anthrax cases were reported in the United States.                Several of these cases resulted from exposure to drums made from anthrax-contaminated animal skins.       

B. anthracis can be found worldwide but is endemic in South America, the Middle East, Africa, and Central Asia. 

One of the largest anthrax outbreaks occurred in Zimbabwe (Rhodesia) in the late 1970s and early 1980s during a period of civil unrest. Researchers estimate that the outbreak infected over 170,000 cattle and over 17,000 humans and caused approximately 200 deaths. 

In 2009 and 2010, an outbreak of anthrax occurred among injection drug users in Europe and the United Kingdom. Anthrax-contaminated heroin was blamed for the outbreak. Fifty-four cases and 17 fatalities were attributed to this outbreak. 

In World War I, the German army attempted to use anthrax to poison animals and animal feed in several countries; however, their efforts were not successful. From 1932 to 1945, Japanese troops occupying China experimented with anthrax and other biological weapons, and it is estimated that 10,000 prisoners may have died as a result. During World War II, the British military tested anthrax delivery systems on an island off the Scottish Coast. The U.S. military also worked on developing anthrax bioweapons and filled more than 5,000 bombs with the substance for use against Germany.     

Development of bioweapons continued in the 1950s and 60s; however, concern over their potential use began growing. In 1969, President Nixon ended the bioweapons program through an executive order. This order also called for the destruction of all bioweapons and a commitment by the U.S. to refrain from using toxic or biological weapons. In 1972, over 100 countries signed a treaty that prohibited the development, stockpiling, and use of biological weapons. 

Despite signing the treaty in 1972, the Soviet Union continued research on bioweapons. In 1979, a large anthrax outbreak occurred in Sverdlovsk (now Ekaterinburg, Russia). Soviet officials claimed that the outbreak was related to anthrax-contaminated animals sold on the black market; however, in 1992, Russian officials admitted that the outbreak occurred due to an accident at a bioweapons factory. A clogged air filter was removed but not replaced, and this incident allowed for the release of anthrax. Soviet Officials reported that 64 of the 96 affected individuals died from gastrointestinal anthrax.   

One article published in the medical literature suggested that the Russians had developed a genetically engineered strain of anthrax. During the Gulf War in the 1990s, there were fears that Iraq might have this genetically engineered anthrax strain that would make the vaccinated U.S. troops vulnerable. However, there has been no public confirmation that Iraq or any other country outside of Russia has developed a genetically engineered, weaponized strain of anthrax that can be successfully deployed in the form of a bioterrorism weapon to harm U.S. citizens.     

In July 1993, an attempted anthrax attack occurred in Japan by members of a religious organization. This attack, however, was not confirmed at the time since there were no reports of anthrax-associated illnesses during the days in question. Confirmation that the liquid suspension aerosolized from the rooftop of a building in Tokyo contained anthrax spores did not occur until November 1999, when the one remaining sample was sent to a lab in Arizona for identification. This lab confirmed the presence of anthrax with a genotype found to be identical to the strain used in the anthrax vaccine targeting animals in Japan. 

In 2001, a bioterrorism attack caused 22 individuals to develop anthrax (11 inhalation and 11 cutaneous) after envelopes containing anthrax spores were mailed to various U.S. government officials and news media outlets. Twenty of the 22 cases were linked to handling mail items, and five people died as a result. 

Genetic testing on the anthrax-contaminated letters confirmed the Ames strain variant of anthrax, developed during experimental research originating at the U.S. Army Medical Research Institute of Infectious Disease (USAMRIID) at Fort Detrick, Maryland. 

Reportedly, the Ames strain of anthrax was provided to other labs doing anthrax research, including Porton Down, a British military lab; Louisiana State University; Northern Arizona University; as well as Dugway Proving Ground Military Research facility in Utah, where anthrax spores were reportedly processed into the powder form that can be inhaled easily. The fact that the genetically engineered and weaponized anthrax strain used in the anthrax-contaminated mail could be traced back to a U.S. military research facility suggested internal lab security issues that needed to be addressed.   

Federal health officials and military anthrax experts urged Capitol Hill staffers and thousands of U.S. Postal Service employees in Washington D.C, New York, and New Jersey, possibly exposed to mail contaminated with the experimental strain of anthrax, to receive anthrax vaccines.     

The civilians were urged to get the shots and complete a two-month course of antibiotics. Health officials maintained that anyone exposed to the experimental anthrax bacteria could harbor anthrax spores in their lungs and become ill once they stop using the antibiotics.  

There hasn’t been a successful delivery of weaponized inhalation anthrax to any large population through a bomb, missile, crop duster, or any other means. If the anthrax bacteria is used as a biological weapon to kill large numbers of people, it will most likely be used in the deadly aerosol form so that large numbers of people will inhale it. This will mean that the anthrax strain and size of spores will have to be designed explicitly for weapons purposes and will require an effective delivery system.  

IMPORTANT NOTE: NVIC “Quick Facts” is not a substitute for becoming fully informed about anthrax and the anthrax vaccine. NVIC recommends consumers read comprehensive information NVIC provides on anthrax, the vaccine manufacturer product information inserts, and speak with one or more trusted health care professionals before making a vaccination decision for yourself or your child.