Bacteria, Epidemiology, Infectious Diseases, Microbiology, rare infectious disease

Glanders, The Rare Infectious Disease That’s Also a Deadly Biological Weapon

Author Chandana Balasubramanian , 21-Nov-2023

Glanders is a highly contagious bacterial infection mainly affecting horses, donkeys, and other animals. While human glanders’ infections are rare, the disease can be transmitted to people through direct contact with infected animals or contaminated materials.


You may wonder, “If glanders is such a rare, infectious disease, why bother learning about it?”


The answer lies in the dark history of glanders being used as a biological weapon in war and the possibility that it may be used again. 


Staying informed, tracking outbreaks, and taking the right precautions can help save lives from known bioterror agents. 


This article explores the history of the zoonotic disease glanders, including its use in war, the first recorded human case, symptoms, diagnostic methods, available treatment, and preventive strategies. 




Glanders, caused by the bacteria Burkholderia mallei, has a long history dating back to ancient times. The disease was first described in horses by Greek and Roman veterinarians. It is believed to have originated in the Middle East and spread during military campaigns and trade routes.

Glanders was a significant concern in the 19th and early 20th centuries, affecting horses and mules used for transportation, agriculture, and warfare.

The first documented case of human glanders was in 1793. Since then, sporadic cases of glanders in humans have been reported, mostly in individuals working with infected animals or regions where the disease is endemic.

It was first used as a bioweapon during World War I, primarily by the German army. At the time, horses were reportedly infected and used to contaminate the clothing, food, and water supplies of enemy forces. The former Soviet Union has also been reported to have used Glanders as a biological weapon of terror in their fight against Afghanistan in 1982-1984. 

Glanders can be an effective biological weapon because:

  • It is highly contagious; small amounts of the bacteria can quickly transmit the infection to more people.
  • The Glanders bacteria, b.mallei, can be easily aerosolized and dispersed as fine particles, which an unsuspecting public can inhale. It can even contaminate public water supplies.
  • It has a high fatality rate when untreated. Even when antibiotic therapy is provided, if the infection spreads throughout the body, the death rate is a high 50%.
  • Glanders symptoms can take up to five days to appear. During this incubation period, infected individuals who do not know they are sick may spread the disease.
  • Glanders in humans is rare, and symptoms may be misdiagnosed, leading to larger outbreaks.


Glanders gets its name from the old French word for glands to signify the swollen lymph nodes under the jawbone (submandibular lymph nodes). Other names for glanders include equinia, droes, malleus, and farcy.



Glanders has a wide range of hosts, including horses, donkeys, mules, and other animals. It can affect domesticated pets like dogs and cats as well. 

The disease has been eliminated from the United States but is found in Africa, Asia, the Middle East, Central America, and South America.

People who have direct contact with infected animals, such as veterinarians, laboratory workers, and horse handlers, are at the highest risk of contracting the disease.

Most glanders cases in humans occurred before antibiotics were available. Back then, more than 90% of people who got infected with b.mallei died. With antibiotic treatment, the mortality rate is 50%. 


How is it spread?

Glanders can be transmitted to humans through direct contact with the body fluids or tissues of infected animals, according to the US CDC (Centers for Disease Control and Prevention). 

In humans, the bacteria can enter the body through skin abrasions or infected droplets in the eyes or nose. 


Biology of the disease

Once inside the body, the gram-negative bacteria Burkholderia mallei can cause a range of symptoms depending on the route of infection. 

The bacteria can invade various organs, including the lungs, skin, lymph nodes, and liver, forming nodules, abscesses, and ulcers. 

Glanders can manifest as acute or chronic forms, with symptoms such as fever, fatigue, respiratory distress, skin lesions, and swollen lymph nodes. It can often be a lung infection that shows up as a localized infection on X-rays.

If the bacteria enters the bloodstream, these infections are highly fatal and can lead to death within 7-10 days. 



Symptoms of glanders can develop within 1-5 days of getting infected.

Common glanders symptoms include:

  • Fever
  • Chills
  • Sweating
  • Muscle pain
  • Chest pain
  • Headache.


Some people may experience light sensitivity and tearing of the eyes. However, as glanders can infect the body through various routes, symptoms can vary depending on the type of infection.

In humans, glanders is 95% fatal without treatment. With treatment, the mortality rate drops to 50%, which is still a high percentage.



There is no one specific test to help diagnose glanders. Identifying the bacterial infection involves isolating the bacteria using different tests. Blood cultures, polymerase chain reaction (PCR) assays, and serological tests may be used to confirm the presence of Burkholderia mallei in the body. 

However, the disease is rare, which means specialized laboratories and expertise may be required for an accurate diagnosis. It may also be often misdiagnosed with melioidosis, another rare bacterial infection. Melioidosis  is commonly known as Whitmore’s disease.



There is limited information on treating glanders because the disease is rare in humans. However, being a bacterial infection, glanders is treated with a combination of antibiotics. The US CDC recommends two rounds of antibiotics, the first intravenously and the second orally.

Glanders can be challenging to treat, but the US CDC notes that Sulfadiazine has been effective.



Currently, there is no vaccine for glanders.

Primarily, preventing glanders involves strict biosecurity measures. This includes isolating and quarantining infected animals, implementing proper hygiene practices, and disinfecting contaminated areas. 

Prevention efforts should focus on improving animal health management, surveillance, and public awareness.



In conclusion, understanding the rare but potent threat of glanders can help safeguard against its use as an agent of bioterror. B.mallei, the bacteria causing glanders, is highly contagious and can be aerosolized; the disease is often misdiagnosed, making it difficult to treat in time. 

With a dark history in biological warfare, this bacterial infection requires vigilance to mitigate risk and prevent widespread devastation. While the disease has been eliminated in some regions, it persists globally, so ongoing awareness and prevention efforts are necessary to prevent outbreaks. 

Adding to the danger, no vaccine exists. Strict animal handling protocols, tracking outbreaks, and developing better diagnostic tools and treatment can help lower the threat level from glanders.


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Chandana Balasubramanian

Chandana Balasubramanian is an experienced healthcare executive who writes on the intersection of healthcare and technology. She is the President of Global Insight Advisory Network, and has a Masters degree in Biomedical Engineering from the University of Wisconsin-Madison, USA.

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