Two fatal drumming-related inhalational anthrax incidents occurred in 2006 and 2008 in the UK. One individual was a drum maker and drummer from the Scottish Borders, most likely infected whilst playing a goat-skin drum contaminated with Bacillus anthracis spores; the second, a drummer and drum maker from East London, likely became infected whilst working with contaminated animal hides.

We have collated epidemiological and environmental data from these incidents and reviewed them alongside three similar contemporaneous incidents in the USA. Sampling operations recovered the causative agent from drums and drum skins and from residences and communal buildings at low levels. From these data, we have considered the nature of the exposures and the number of other individuals likely to have been exposed, either to the primary infection events or to subsequent prolonged environmental contamination (or both).

Despite many individual exposures to widespread low-level spore contamination in private residences and in work spaces for extended periods of time (at least 1 year in one instance), only one other individual acquired an infection (cutaneous). Whilst recognising the difficulty in making definitive inferences from these incidents to specific residual contamination levels, and by extending the risk to public health, we believe it may be useful to reflect on these findings when considering future incident management risk assessments and decisions in similar incidents that result in low-level indoor contamination.

Bacterial endospores are resistant to many environmental factors from temperature extremes to ultraviolet irradiation and are generally more difficult to inactivate or kill than vegetative bacterial cells. It is often considered necessary to treat spores or samples containing spores with chemical fixative solutions for prolonged periods of time (e.g., 1–21 days) to achieve fixation/inactivation to enable electron microscopy (EM) examination outside of containment laboratories. Prolonged exposure to chemical fixatives, however, can alter the ultrastructure of spores for EM analyses. This study was undertaken to determine the minimum amount of time required to inactivate/sterilize and fix spore preparations from several bacterial species using a universal fixative solution for EM that maintains the ultrastructural integrity of the spores. We show that a solution of 4% paraformaldehyde with 1% glutaraldehyde inactivated spore preparations of Bacillus anthracis, Bacillus cereus, Bacillus megaterium, Bacillus thuringiensis, and Clostridium perfringens in 30 min, and Bacillus subtilis in 240 min. These results suggest that this fixative solution can be used to inactivate and fix spores from several major groups of bacterial spore formers after 240 min, enabling the fixed preparations to be removed from biocontainment and safely analyzed by EM outside of biocontainment.

In a Belgian wool-processing factory, living anthrax spores were found in raw goat hair and air dust, but confirmed anthrax cases had never been reported. Anthrax vaccines are not licensed nor recommended in Belgium. We conducted a B. anthracis seroprevalence study to investigate risk factors associated with positive serology and advise on protective measures. Overall 12·1% (8/66) employees were seropositive; 30% of persons processing raw goat hair and 20% of persons sorting raw goat hair were seropositive compared to 3% in less exposed jobs [adjusted prevalence ratio (aPR) 44·4, P=0·001; aPR 14·5, P=0·016, respectively). The number of masks used per day was protective (aPR 0·3, P=0·015). Results suggest a dose–response association for those processing raw goat hair. Host-related factors probably played a role as antibody response varied from person to person within an exposure group. Workers exposed to raw goat hair should be offered higher protection against anthrax and have access to anthrax vaccines.

Since 2003, Connecticut laboratories have reported Gram-positive rod (GPR) isolates detected within 32 h of inoculation from blood or cerebrospinal fluid. The objectives were to rapidly identify inhalational anthrax and unusual Clostridium spp. infections, and to establish round-the-clock laboratory reporting of potential indicators of bioterrorism. From 2003 to 2006, Connecticut's GPR surveillance system identified 1134 isolates, including 657 Bacillus spp. (none B. anthracis) and 241 Clostridium spp. Reporting completeness and timeliness improved to 93% and 92%, respectively. Baseline rates of Bacillus spp., Clostridium spp. and other GPR findings have been established and are stable. Thus far, no cases of anthrax and no unusual clusters of Clostridium spp. have been detected by the GPR surveillance system. This system would probably have confirmed the inhalational anthrax case in Pennsylvania in 2006 3 days sooner than traditional reporting. Using audits and ongoing evaluation, the system has evolved into a highly functional 24/7 laboratory telephone reporting system with almost complete reporting.

Anthrax is the disease caused by the Gram-positive bacterium Bacillus anthracis. Two toxins secreted by B. anthracis – lethal toxin (LT) and oedema toxin (OT) – contribute significantly to virulence. Although these toxins have been studied for half a century, recent evidence indicates that LT and OT have several roles during infection not previously ascribed to them. Research on toxin-induced effects other than cytolysis of target cells has revealed that LT and OT influence cell types previously thought to be insensitive to toxin. Multiple host factors that confer sensitivity to anthrax toxin have been identified recently, and evidence indicates that the toxins probably contribute to colonisation and invasion of the host. Additionally, the toxins are now known to cause a wide spectrum of tissue and organ pathophysiologies associated with anthrax. Taken together, these new findings indicate that anthrax-toxin-associated pathogenesis is much more complex than has been traditionally recognised.