Summary about Disease
Glanders is a highly contagious and often fatal infectious disease that primarily affects horses, mules, and donkeys. It can also infect humans and other animals, although this is less common. It is caused by the bacterium Burkholderia mallei. Glanders is considered a zoonotic disease, meaning it can be transmitted from animals to humans. The disease is characterized by the formation of nodular lesions in the lungs, skin, and mucous membranes. Historically, glanders was a significant concern, but it has been largely eradicated from many parts of the world.
Symptoms
Symptoms of glanders vary depending on the form of the disease and the host animal. In horses, three forms are typically recognized:
Nasal glanders: Characterized by ulcers and mucopurulent discharge from the nasal passages. Swollen lymph nodes under the jaw are also common ("farcy buds").
Cutaneous glanders (Farcy): Characterized by nodules and ulcers on the skin, particularly on the limbs, flanks, and chest. Lymphangitis (inflammation of the lymphatic vessels) is also common.
Pulmonary glanders: Characterized by pneumonia, coughing, and difficulty breathing. In humans, symptoms can include:
Fever
Muscle aches
Chest pain
Headache
Nasal discharge
Skin lesions
Pneumonia
Septicemia
Causes
Glanders is caused by the bacterium Burkholderia mallei. The bacteria typically enter the body through:
Ingestion of contaminated food or water
Inhalation of aerosolized bacteria
Contact with infected skin lesions or mucous membranes
Contact with contaminated fomites (e.g., equipment, bedding)
Medicine Used
Treatment of glanders typically involves long-term antibiotic therapy. The specific antibiotics used and the duration of treatment can vary depending on the severity of the infection and the host species. Common antibiotics used include:
Meropenem
Imipenem-cilastatin
Doxycycline
Trimethoprim-sulfamethoxazole (TMP-SMX)
Ciprofloxacin
Ceftazidime
Amoxicillin-clavulanate Combination therapy may be necessary to improve outcomes. Treatment courses are often prolonged (weeks to months) to prevent relapse.
Is Communicable
Yes, glanders is a communicable disease. It can be transmitted between animals and from animals to humans (zoonotic). Transmission can occur through:
Direct contact with infected animals or their bodily fluids
Inhalation of aerosolized bacteria
Ingestion of contaminated food or water
Contact with contaminated fomites (e.g., equipment, bedding).
Precautions
Preventing the spread of glanders involves several precautions:
Early detection and reporting: Promptly identify and report suspected cases to veterinary and public health authorities.
Quarantine: Isolate infected animals to prevent further transmission.
Euthanasia: In many cases, euthanasia of infected animals is necessary to control the disease and prevent further spread.
Disinfection: Thoroughly disinfect contaminated areas, equipment, and fomites using appropriate disinfectants.
Personal protective equipment (PPE): Individuals handling infected animals or contaminated materials should wear appropriate PPE, including gloves, masks, and eye protection.
Avoidance: Avoid contact with animals in regions where glanders is known to be present.
Vaccination: There is no widely available or effective vaccine for glanders.
Education: Educate animal handlers and the public about the disease and how to prevent its spread.
How long does an outbreak last?
The duration of a glanders outbreak can vary depending on several factors, including:
Early detection and intervention: Prompt identification and implementation of control measures can shorten the outbreak.
Extent of the outbreak: Larger outbreaks with more infected animals will generally take longer to control.
Effectiveness of control measures: The effectiveness of quarantine, euthanasia, and disinfection measures will influence the duration.
Environmental factors: Environmental conditions can affect the survival and spread of the bacteria. Outbreaks can last for several weeks to months, or even longer if control measures are not effectively implemented. In some cases, eradication efforts can take years.
How is it diagnosed?
Diagnosis of glanders involves a combination of clinical signs, laboratory tests, and epidemiological information. Diagnostic methods include:
Clinical examination: Assessing the animal for characteristic symptoms, such as nasal discharge, skin lesions, and swollen lymph nodes.
Bacterial culture: Isolating and identifying Burkholderia mallei from clinical samples (e.g., nasal discharge, skin lesions, blood).
Serological tests: Detecting antibodies against Burkholderia mallei in blood samples. Common serological tests include the complement fixation test (CFT), mallein test, and ELISA.
Polymerase chain reaction (PCR): Detecting Burkholderia mallei DNA in clinical samples.
Mallein test: An older test involving the intradermal injection of mallein (a bacterial extract) and observation for a local reaction. This test is less commonly used now due to concerns about sensitivity and specificity.
Timeline of Symptoms
The incubation period for glanders is typically 1-14 days, but can sometimes be longer. The progression of symptoms varies depending on the form of the disease:
Early Stage (Days 1-14 after exposure):
Fever may be present.
General malaise and muscle aches.
Nasal Form:
Onset of nasal discharge (initially serous, then mucopurulent).
Ulcers develop in the nasal passages.
Swelling of the lymph nodes under the jaw (farcy buds).
Cutaneous Form (Farcy):
Nodules appear on the skin, particularly on the limbs.
Nodules ulcerate and discharge pus.
Lymphangitis (inflammation of lymphatic vessels) develops.
Pulmonary Form:
Coughing.
Difficulty breathing.
Pneumonia.
Late Stage (Without treatment):
Progressive debilitation.
Spread of infection to other organs.
Septicemia.
Death.
Important Considerations
Glanders is a serious zoonotic disease with a high mortality rate, particularly if left untreated.
Prompt diagnosis and treatment are crucial for improving outcomes.
Control and eradication efforts require a coordinated approach involving veterinary and public health authorities.
Strict biosecurity measures are essential to prevent the spread of the disease.
Due to its potential as a biological weapon, Burkholderia mallei is considered a select agent, and its possession, use, and transfer are strictly regulated.
Although eradicated from many parts of the world, glanders remains a concern in certain regions, particularly in parts of Asia, Africa, and South America.
Surveillance and monitoring are important for detecting and responding to potential outbreaks.
Research is ongoing to develop improved diagnostic tests and treatments for glanders.