Healthy 18-year-old nearly died in ninth reported case of 'welder's anthrax'

Public health investigators say a healthy 18-year-old welder nearly died after infection with an anthrax-toxin–producing Bacillus, the ninth such puzzling case linked to metalworkers. CDC researchers in 2022 identified an unexpected pattern: since 1997 seven cases of infections from Bacillus group bacteria that produce the anthrax toxin had all occurred in metalworkers.

Six of those seven were welders and one was a foundry worker who ground metal. Of six cases where the species was identified, B. tropicus was responsible; the newly reported case also involved B. tropicus. The teen worked about four hours a day, four days a week, often in poorly ventilated or confined spaces and frequently without personal respiratory protection.

Environmental testing at his workplace found anthrax-toxin–producing Bacillus in 28 of 254 spot samples. Experts say it is unclear why welders appear uniquely vulnerable. They have speculated the risk may come from a combination of weakened lung immune defenses after inhaling toxic metal fumes and gases and increased exposure to Bacillus in some workplaces.

Investigators have also suggested iron exposure could matter: Bacillus bacteria require iron to thrive, and metalworking can lead to excess iron in the respiratory tract. In this case the welder was using carbon steel and low-hydrogen carbon steel electrodes.

Key Topics

Health, Bacillus Tropicus, Welder's Anthrax, Welders, Cdc, Louisiana