Injectional anthrax at a Scottish district general hospital

Abstract

This retrospective, descriptive case-series reviews the clinical presentations and significant laboratory findings of patients diagnosed with and treated for injectional anthrax (IA) since December 2009 at Monklands Hospital in Central Scotland and represents the largest series of IA cases to be described from a single location. Twenty-one patients who fulfilled National Anthrax Control Team standardized case definitions of confirmed, probable or possible IA are reported. All cases survived and none required limb amputation in contrast to an overall mortality of 28% being experienced for this condition in Scotland. We document the spectrum of presentations of soft tissue infection ranging from mild cases which were managed predominantly with oral antibiotics to severe cases with significant oedema, organ failure and coagulopathy. We describe the surgical management, intensive care management and antibiotic management including the first description of daptomycin being used to treat human anthrax. It is noted that some people who had injected heroin infected with Bacillus anthracis did not develop evidence of IA. Also highlighted are biochemical and haematological parameters which proved useful in identifying deteriorating patients who required greater levels of support and surgical debridement.

Heroin-associated anthrax with minimal morbidity

“…As stated, the lesion in this case had certain features which would potentially be compatible with CA—papular in appearance, local oedema and golden vesicles. Despite the latter being described with CA, they have been seen both in other local IA cases4 and described in IA by other investigators 7. The notable absence of necrotic eschar in PWID anthrax has been considered to be more characteristic of IA than CA 10.…”

“…They were all heroin users 3. Sporadic cases of IA have occurred since the outbreak was declared over 4 5…”

“…The minority of local IA cases required aggressive surgery, and two patients required no surgery in a local review of cases 4. Jallali et al 7 report two further IA cases in London who also required no surgical intervention.…”

Anthrax Toxins in Context of Bacillus anthracis Spores and Spore Germination

“…A comparatively new form of human disease, injectional anthrax, has been observed among intravenous drug users, i.e. , heroin addicts in Western Europe [ 29 , 30 , 31 , 32 , 33 , 34 ]. This disease can range from cutaneous/intradermal to septicemic anthrax [ 32 ].…”

Anthrax in injecting drug users: the need for increased vigilance in the clinic

“…A number of further diagnostic tests may be employed to confirm IA cases; these fall broadly into assays which detect the presence of the bacteria, such as fluorescence immunoassays and mass spectrometry identifying cell-associated proteins [25][26][27] and assays which detect the presence of antibodies to PA and LF [28,29]. Several caveats must be borne in mind though when considering these methods, as phenotypic characteristics may vary between strains and hemolytic, motile bacilli, which are resistant to phage lysis, have been identified in B. anthracis isolates, closely related Bacillus species may lead to misdiagnosis, and (perhaps most importantly) antimicrobial therapy rapidly decreases the sensitivity of these assays [30]. Although it has been found that LF-specific IgG can be detected early in infection [29], assays based upon the development of an immune response to anthrax antigens may have limited utility in the clinic [30], and instead may be useful in retrospective epidemiological investigations [19,24].…”