New cases of injectional anthrax reported in Western Europe appear to be genetically related to strains seen in a previous drug-related anthrax outbreak, recent study data found.
Additionally, the resurfacing of drug abuse-related anthrax suggests that heroin use may act as an ongoing means of transmission for Bacillus anthracis in Western Europe, according to researchers from Germany and Arizona who collaborated on this project funded by the US Department of Homeland Security Science and Technology Directorate.
The researchers obtained culture-positive samples from some of the patients affected by the 2009-2010 outbreak of drug abuse-related anthrax that occurred in the United Kingdom and Germany. These samples were collaboratively genotyped using a high-resolution molecular approach. This analysis was aimed at determining the epidemiology and geographic origin of the strains, according to the study findings published recently as a letter in Emerging Infectious Diseases.
All cases in this outbreak were related to a single B. anthracis strain type belonging to a large Trans-Eurasian B. anthracis group, Ba4599. Strains related to those identified in association with European drug use, which belong to the A.Br. 008/011 canSNP cluster, have been found to originate in Turkey. However, the researchers continue to investigate additional isolates from other relevant areas to determine their geographic origins.
After the 2012 appearance of two new cases of heroin-related injection anthrax in Bavaria, subsequent cases were reported in Germany, Denmark, France and the United Kingdom. As of August 2013, there were 26 deaths resulting from this resurgence.
The study researchers used phylogenetic methods to assess the relationship between these strains and Ba4599. Genotyping results established that these strains were along the branch A.Br.008 within the Trans-Eurasian group of B. anthracis. Additional fine-scale typing of these isolates determined that all isolates were identical at the single nucleotide polymorphisms (SNPs). Further evaluation by multiple locus variable number tandem repeats indicated that all strains differed at just two markers and were closely related. The researchers hypothesized that all of the injectional anthrax isolates likely originated from the same location.
The researchers said the study demonstrates the utility of molecular genotyping in discovering the origins of infectious disease vehicles. In addition, the recent reappearance of injectional anthrax, which has particularly high death rates, could serve to impart an educational and cautionary message to the public.
“Ideally, this unfortunate deadly incident could offer an opportunity to sensitize heroin users to the risks for severe infection and educate public health officials to be vigilant for this rare disease,” the researchers wrote.
Disclosure: The researchers report no relevant financial disclosures.