Top 5 Takeaways

1. Fatal Cases in Welders: Two cases of pneumonia in welders caused by Bacillus cereus group bacteria containing anthrax toxin genes were confirmed in 2020, one of which was fatal.
2. High Mortality Rate: Among seven reported cases of pneumonia caused by these bacteria since 1994, five patients died, and two had critical illness with prolonged recovery.
3. Geographic and Occupational Risk: All affected individuals were welders or metalworkers in Louisiana or Texas, highlighting a specific occupational and geographic risk.
4. Environmental Exposure: A bacterial isolate from a soil sample at one patient’s worksite matched the clinical isolate, suggesting environmental exposure as a potential source.
5. Preventive Measures: Employers should educate workers about the hazards of welding, conduct hazard assessments, and consider the use of NIOSH-approved respirators to minimize exposure risks.

Original Article Author and Citation

Corresponding Author

William A. Bower, wab4@cdc.gov

Suggested Citation

Dawson P, Schrodt CA, Feldmann K, et al. Notes from the Field: Fatal Anthrax Pneumonia in Welders and Other Metalworkers Caused by Bacillus cereus Group Bacteria Containing Anthrax Toxin Genes — U.S. Gulf Coast States, 1994–2020. MMWR Morb Mortal Wkly Rep 2021;70:1453–1454. DOI: http://dx.doi.org/10.15585/mmwr.mm7041a4

Summary

In 2020, the CDC confirmed two cases of pneumonia in welders caused by Bacillus cereus group bacteria containing anthrax toxin genes, with one case being fatal. Since 1994, seven such cases have been reported in the U.S., primarily among welders and metalworkers in Louisiana and Texas. The bacteria, typically found in soil and dust, can cause severe pulmonary infections, particularly in individuals exposed to welding fumes.

Methods

The investigation included clinical diagnoses, environmental sampling, and genetic matching of bacterial isolates from patients and their work environments. The CDC conducted a detailed examination of the patients’ workplaces to identify potential sources of infection.

Discussion

The findings highlight a specific occupational risk for welders and metalworkers in the U.S. Gulf Coast states. Long-term exposure to welding fumes may increase susceptibility to severe pulmonary infections. The study underscores the need for targeted preventive measures and awareness among workers and employers in these industries.

Conclusion

To reduce the risk of fatal pneumonia caused by Bacillus cereus group bacteria, it is crucial for employers to educate workers, conduct hazard assessments, and implement respiratory protection programs. Clinicians should consider these bacteria in differential diagnoses for welders with severe pneumonia and pursue appropriate testing and treatment protocols.

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