Glanders

Glanders is defined as a zoonotic infectious disease caused by the Gram-negative bacterium Burkholderia mallei, a member of the B. pseudomallei complex within the Burkholderia genus ^[1][2]. The disease nomenclature originates from historical terms denoting glands, reflecting the characteristic nodular lesions observed during infection, with regional synonyms including Latin malleus, Spanish muermo, German Rotz, and Norwegian snive ^[1]. Species within this genus exhibit substantial intrinsic antimicrobial resistance driven by modified lipopolysaccharides, restricted porin-mediated drug penetration, efflux pump activity, and β-lactamase expression, which complicates microbiological identification and clinical management ^[2].

Clinical illness typically follows either an acute or chronic trajectory and presents with nonspecific symptoms that frequently impede rapid diagnosis ^[1]. The acute variant progresses rapidly through coughing, fever, and infectious nasal discharge before advancing to septicaemia and mortality within days ^[1]. Conversely, the chronic form involves the gradual development of nasal and subcutaneous nodules that eventually ulcerate, potentially leading to death over several months while survivors may function as asymptomatic carriers ^[1]. Affected equids similarly develop pulmonary nodules and upper respiratory tract mucosal ulcerations ^[1].

The disease maintains endemic circulation in African, Asian, Middle Eastern, and Central and South American regions, where it predominantly infects horses, mules, and donkeys with documented cross-species transmission to companion animals, livestock, and humans ^[1]. Systematic veterinary monitoring, targeted animal destruction, and strict import quarantines successfully eliminated the pathogen from North America, Australia, and much of Europe ^[1]. Historical human incidence in non-endemic countries is exceptionally low, with the United States recording its last natural case in 1945 and the United Kingdom reporting none since 1928, aside from isolated laboratory exposures ^[1].

Pathogen entry into humans occurs through direct contact with infected animal tissues and bodily fluids, facilitating inoculation via dermal abrasions, oral or nasal mucosal surfaces, and respiratory inhalation ^[1]. Primary establishment of infection in reservoir hosts generally results from consuming contaminated feed or drinking water ^[1]. Because the organism readily crosses species barriers to infect people, it is formally categorized as a zoonotic agent ^[1].

Current preventive strategies rely heavily on historical veterinary protocols, including systematic animal inspection, immediate culling of symptomatic individuals, and stringent quarantine measures governing international livestock trade ^[1]. There is currently no licensed vaccine available in the United States, a therapeutic gap that has accelerated research efforts given the microorganism's potential for weaponization ^[1]. Mitigation in high-risk environments therefore depends on rigorous biosafety practices and environmental controls rather than immunization ^[1].

1. 1Wikipedia contributors. Glanders - Wikipedia [Internet]. Wikipedia. cited 4 Sept 2026.Available from: https://en.wikipedia.org/wiki/Glanders
2. 2Rhodes KA et al. Antibiotic resistance in Burkholderia species. Drug Resist Updat. 2016 Sep. PMID: 27620956. doi: 10.1016/j.drup.2016.07.003.PubMed: https://pubmed.ncbi.nlm.nih.gov/27620956/