Abstract: Glanders is an infectious disease that occurs primarily in horses, mules, and donkeys. It can be contracted by other animals such as dogs, cats and goats. It is caused by infection with the bacterium Burkholderia mallei, usually by ingestion of contaminated food or water. Symptoms of glanders include the formation of nodular lesions in the lungs and ulceration of the mucous membranes in the upper respiratory tract. The acute form results in coughing, fever and the release of an infectious nasal discharge, followed by septicaemia and death within days. In the chronic form, nasal and subcutaneous nodules develop, eventually ulcerating. Death can occur within months, while survivors act as carriers.
Glanders is endemic in Africa, Asia, the Middle East, Central and South America. It has been eradicated from North America, Australia and most of Europe through surveillance and destruction of affected animals, and import restrictions.
Burkholderia mallei is able to infect humans and is therefore classed as a zoonotic agent. Transmission occurs by direct contact with infected animals and entry is through skin abrasions, nasal and oral mucosal surfaces, or by inhalation.
The mallein test is a sensitive and specific clinical test for glanders. Mallein (ATCvet code: QI05AR01), a protein fraction of the glanders organism (Burkholderia mallei), is injected intradermo-palpebrally or given by eye-drop. In infected animals, the eyelid swells markedly in 1 or 2 days.
Glanders has not been reported in the United States since 1945.
Due to the high mortality rate in humans and the small number of organisms required to establish infection, Burkholderia mallei is regarded as a potential biological warfare (BW) or bioterrorism agent, as is the closely related organism, Burkholderia pseudomallei, the causative agent of melioidosis. During World War I, Glanders was believed to have been spread deliberately by German agents to infect large numbers of Russian horses and mules on the Eastern Front. Other agents attempted to introduce the disease in the United States and Argentina. This had an effect on troop and supply convoys as well as on artillery movement, which were dependent on horses and mules. Human cases in Russia increased with the infections during and after WWI. The Japanese deliberately infected horses, civilians, and prisoners of war with B. mallei at the Pinfang (China) Institute during World War
The U.S. studied this agent as a possible BW weapon in 1943–44 but did not weaponize it. U.S. interest in Glanders (Agent LA) continued through the 1950s, except it had an inexplicable tendency to lose virulence in the lab, making it difficult to weaponize. The Soviet Union is also believed to have been interested in B. mallei as a potential BW agent after World War II (Wikipedia, 2012).