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.
