Glanders

Synonym: Farcy, Malleus

• It is highly contagious bacterial disease of equine characterized by formation of nodules and ulcers involving upper air passage, lungs and cutaneous tissues.
• Disease is zoonotic in nature.

Etiology:

• Actinobacillus mallei (Pseudomonas mallei, Malleomyces mallei, Pfifferella mallei, Leofferella mallei)
• At present, organism is known as Burkhoidera mallei.
• Gram-ve, straight or slightly bent, non-spore forming, facultative, intracellular, rod-shaped bacteria
• Organism grow on glycerol dextrose agar (GDA) as smooth, moist and viscid colonies after 24 hours of inoculation.

Epidemiology:

• Disease was first identified by Hippocrates in 4^th century BC
• It is prevalent in most equine rearing countries; common in Asia, Africa, South America, Eastern Europe, and Middle East.
• Disease has also been recorded from various parts of India like Maharashtra, UP, Haryana, Punjab, Uttarakhand, Andrapradesh, Himanchal Pradesh
• It is now eradicated or effectively controlled in many countries, including the US.
• Starting in 2004, however, glanders began reemerging, first in the Middle East, then in India, followed by a reported case in Europe in 2006.
• Countries and regions where the disease has been reemerging include the Middle East (Kuwait, Lebanon, Iran, Iraq, United Arab Emirates, Bahrain), Afghanistan, Pakistan, India, Mongolia, Nepal, the Philippines, China, South America (Bolivia, Brazil), Africa (Eritrea, Ethiopia), Turkey, and Russia.
• During
• natural infection, it varies from 6 days to several
• months
• During
• natural infection, it varies from 6 days to several
• months
• During natural infection, incubation period varies from 6 days to several months.
• In case of aerosolization, incubation period varies from 10-14 days.
• Horse, mules and donkey’s are highly susceptible. Occasionally, sheep and goat become infected.
• Disease occurs as sporadic cases or small outbreaks in equine populations.
• Stress, poor nutrition, and overcrowding enhance spread.
• Horses can be asymptomatic carriers, shedding organisms intermittently.

Transmission:

• Through secretion or excretion of infected animals by close contact
• Organism are present in discharges of skin and nasal mucosa.
• In acute forms, organisms are excreted in feces, urine, saliva and tears.
• Most common route of transmission is inhalation of infected material.
• Ingestion of infected feed and water contaminated by nasal discharge, sputum.
• Dogs, cats, and wild zoo carnivores acquire infection from ingestion of infected horse meat.
• Through inoculation by contaminated needles, syringes, insects.

Pathogenesis:

Clinical Findings:

• There is chronic nasal discharge from one or both nostrils.
• Discharge is grey in color and catarrhal in nature.
• Formation of small grey or yellowish nodules about the size of millet seed on mucosa of URT
• Submaxillary lymph nodes are edematous in nature.
• Formation of nodules and ulcers along the lymphatic channels of skin.
• Acute form of disease shows high rise of temperature along with ocular and nasal discharge.
• Dyspnea due to swelling of nasal mucosa and edema of glottis.
• Animals dies due to anoxia or septicemia.

Chronic form:

• This form persists for few months or even a year.
• Intermittent fever, cough and respiratory distress
• Lymph nodes of mandible becomes firm and nodular.
• Affected animals gradually lose their condition with poor hair coat.
• Edema of hindlimbs down to hock accompanied with discharges from lymph nodes.
• Ulcer of skin gradually heals up leaving irregular star shaped scar.

Zoonotic form:

• Swelling and pain, usually on the hands, lips or eyes along with swelling of neighboring lymph nodes.
• Ulcer may develop on nose and mouth in some cases.
• Development of abscess and pustules on the skin.
• Symptoms are always preceded by high rise of temperature.

PM Findings:

• Nodules and ulcers are noted in nasal septum and turbinate bones.
• Small nodules are observed throughout legs varying in size from millet to pea.
• Lungs will show tubercle like nodules, which have caseous or calcified centres surrounded by inflammatory zones in the lungs.
• Liver and spleen may show typical nodular lesion.
• In cutaneous form, nodules appear along the course of lymph vessels.

Diagnosis:

• Presumptive diagnosis is based on clinical observation of cutaneous nodules exuding honeylike discharge.
• Typical nodules, scar formation, ulceration and patient debilitated condition may be sufficient for clinical diagnosis.
• Isolation and identification of organism by observation in microscope. Pus smear are stained with methylene blue or gram stain.
• Mallein test is used for allergic test. Mallein reagent is injected intradermally in lower eyelid. Positive reaction is characterized by extensive edema of eyelid, congestion of conjunctiva, and mucopurulent secretion.
• In SC test, 1 ml of ordinary or dilute mallein is injected beneath skin. Positive reaction is obtained by swelling at the point of injection and increase in temperature.
• Serological test: CFT, IHA, ELISA
• Molecular test: PCR
• Strauss reaction: Male guinea pig when inoculated intraperitoneally or SC with suspected material, local reaction takes place involving scrotal sac leading to painful orchitis in positive case.

Differential Diagnosis:

1. Strangles:

• Suppurative lymphadenitis with nasal discharge and abscessed submandibular/retropharyngeal lymph nodes.
• Discharge are thick and creamy.
• It usually affects younger horse.

2. Ulcerative lymphangitis:

• Nodular lesion and lymphatic cord-like swellings on limb/trunk.
• Absence of nasal ulcers or nodules in lungs.
• Organisms are identified by culture/microscopy.

3. Equine viral arteritis (EVA):

• There is fever, nasal discharge
• Edema of limbs and scrotum
• No nodular ulceration or farcy buds

4. Equine influenza:

• Acute high fever, cough
• Serous-mucopurulent nasal discharge resolves quickly
• Lack of ulcerative nodules.

5. Pneumonia:

• No specific ulcerative nasal lesions or cutaneous lymphangitis typical of glanders.
• Cough, dyspnea

Treatment:

• Sulphadrugs is drug of choice. Sulphadiazine + Trimethoprim (Sultrimax) inj. @ 10 ml, IM, OD for 1 week.
• Skin ointment for cutaneous lesion.
• For eradication of disease, affected animals should not be treated because it may result a carrier state.

Control Measures:

• For eradication of disease, affected animal must be destroyed and disposed of safely.
• Dead carcass shouldnot be opened.
• Carcass should be either buried or incinerated.
• Manure, bedding and feed residue should be burnt or buried.
• Premises should be vigorously disinfected with appropriate disinfectant such as sodium hypochlorite (bleach), phenolic disinfectant, formaldehyde, quaternary ammonium compounds.
• Feeding utensil and water trough should be properly disinfected.
• All the suspected, incontacted and imported animal must be isolated, properly tested, and all the positive reactors must be slaughtered.
• There is no vaccine for glanders.
• Person handling the carcass or suspected animal should wear PPE kits during handling or treatment of disease.