Burkholderia mallei and Burkholderia pseudomallei as Bioterrorism Agents: National Aspects of Emergency Preparedness
Jacob Gilad MD1,2, Idit Harary MD1, Tsvika Dushnitsky MD1, David Schwartz PhD2 and Yoram Amsalem MD1
CBRN Medicine Branch, Israel Defense Forces Medical Corps, Tel Hashomer, Israel Clinical Microbiology Laboratory, Tel Aviv Sourasky Medical Center, Tel Aviv, IsraelKey words: bioterrorism, burkholderia, melioidosis, glanders, preparedness
Burkholderia mallei and Burkholderia pseudomallei are the causative organisms of glanders and melioidosis, respectively. Although now rare in western countries, both organisms have recently gained much interest because of their unique potential as bio terrorism agents . Despite being uniqueorganisms, B. mallei and B. pseudomallei share many similarities and may be considered together in the context of a deliberaterelease event. These pathogens are less familiar to medical and labora tory personnel than other select bioterrorism bacterial agents such as Bacillus anthracis, Yersinia pestis and Francisella tularensis and, therefore, a review of glanders and melioidosis is crucial inorder to guide emergency preparedness and response to a deliberaterelease event. The aim of this paper is to review the unique characteristics of these organisms in the context of bioterrorism, with special emphasis on national aspects of preparedness in Israel.
in Iran, and suspected cases in Egypt, the Gulf Emirates and Saudi Arabia, but not Israel. Glanders primarily affects animals and canbe transmitted both from animal to animal and animal to human, while human tohuman transmission is rare, at least in nature. Most human cases during the 20th century were occupational infections among laboratory workers, horse handlers, butchers and veterinarians .
Table 1. Key features contributing to the bioterrorism potential of B. mallei and B. pseudomallei
Aspect Key featuresEpidemiology
• Rare diseases in western countries • Melioidosis endemic in Southeast Asia and Oceania, glanders rare and mostly sporadic • Not a reportable disease in Israel • Environmental persistence (weeks for B. mallei, years for B. pseudomallei) • Infection through inhalation, ingestion or percutaneous inoculation • Low infective doses • Highly variable incubation period • Acute, subacute orchronic disease; possibility of relapse and late reactivation • Wide spectrum of manifestations – “great imitators” • High prevalence of severe sepsis and septic shock • Significant morality • • • • • • • • • • • • • • • Lack of experience among both clinicians and laboratory personnel Identification by routine laboratory methods difficult to impossible Need for specialized laboratory reagents,equipment and expertise Unusual biosafety requirements Complex protocols utilizing intravenous antimicrobials Long duration of therapy (months) Frequent need for surgical interventions and supportive critical care Antimicrobial resistant isolates not uncommon Species highly accessible No national reference laboratory Difficulty in stockpiling relevant antimicrobials Antimicrobial resistance No availablevaccine No evidence regarding postexposure prophylaxis Lack of awareness in Israeli medical community
What makes B. mallei and B. pseudomallei “attractive” bioweapons? These pathogens have many characteristic features that make them nearly “perfect” agents for biological terrorism. Some of these characteristics are shared by the two bacteria, while oth ers are unique or moreprominent in one of them. It should be stressed that despite the abundant literature relating to B. pseudomallei, much of the knowledge of B. mallei relies on indirect evidence or expert opinion. Relevant key features are summarized in Table 1 and are elaborated below. Epidemiology Melioidosis is endemic in several parts of Southeast Asia. During the 20th century, sporadic cases also occurred in...