Of drums and heroin: Anthropogenic spread of anthrose negative Bacillus anthracis

Keywords: anthrax, heroin, drums, medical geography, global health, infectious disease
Abstract Type: Paper Abstract

Abstract

Bacillus anthracis causes anthrax. The bacteria can sporulate and survive dormant for years or decades. Anthrax spores infect ungulate mammals through environmental reservoirs in soil. Humans can be infected from contaminated soils; however, anthrax is more commonly contracted from infected animals or their contaminated agricultural byproducts causing inhalational, cutaneous, and gastrointestinal anthrax depending on route of infection. When an animal dies of anthrax, its tissues are heavily contaminated with spores and consumption or close contact with those materials can infect humans. In recent history, export-related anthrax has been the cause of high-profile public health incidents. Our study initially focused on genetic signatures originally constrained to West African B. anthracis (Nigeria, Chad, Mali, and Cameroon). Those strains contained genomic mutations in the anthrose biosynthetic operon. Anthrose is found on the surface of spores as part of the exosporium nap and plays a role in interactions with the host and environment; removal of anthrose alters these interactions. Genome analysis found several unrelated B. anthracis strains lacked anthrose through disparate genetic mechanisms. These strains caused human anthrax cases across Europe and were linked to djembe drumskins and the illicit heroin trade. Some anthrose-negative strains were found in the US and Turkey. While these incidents are linked to human cultural practices and not to human agricultural practices that have become tightly regulated in the modern age, other livestock-related strains were found in Chile. Collectively, our genomic analysis revealed diverse mechanisms for losing anthrose and a near global distribution over recent decades.