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Bacterial Disease - Glanders

Synonym: Farcy

Glanders is a contagious, acute or chronic, usually fatal disease of Equidae caused by Burkolderia mallei (previously pseudomonas mallei) and characterized by serial development of ulcerating nodules that occur most commonly in the upper respiratory tract, lungs, and skin. Man, Felidae, and other species are susceptible, and infections usually are fatal.

Prevalent

It was prevalent worldwide. It has now been eradicated or effectively controlled in many countries, including the USA. In recent years, the disease has been reported in Iraq, Turkey, India, Mongolia, and China.

Etiology

Burkolderia mallei (previously pseudomonas mallei) is present in exudates of the nose and ulcerated skin of infected animals and the disease is commonly contracted by ingesting food or water contaminated by the nasal discharge of carrier animals. The organism is susceptible to heat, light and disinfectants; it is unlikely to survive in a contaminated area for >6 wk. Humid, wet conditions favor survival of the organism.

Clinical findings

After an incubation period of 2 week, affected animals usually have septicemia and high fever (upto 106°F [41°C]) and, subsequently, a thick, mucopurulent nasal discharge and respiratory signs.

v Death occurs within a few days. The chronic disease is common in horses and occurs as a debilitating condition with nodules or ulcerative cutaneous and nasal lesions.

Infected animals may live for years and disseminate the organism. The prognosis is unfavorable. Recovered animals may not develop immunity.

There are three forms of glanders

Nasal form

Nodules develop in the mucosa of the nasal septum and lower part of the turbinate's. The nodules degenerate into deep ulcers with raised irregular borders. Characteristic star-shaped cicatrices remain after the ulcers heal. In the early stage, the sub maxillary lymph nodules are enlarged and edematous, and later become adherent to the skin or deeper tissues.

Pulmonary form

Small tubercle-like nodules, which have caseous or calcified centers surrounded by inflammatory zones, are found in the lungs. If the disease process is extensive, consolidation of the lung tissue and pneumonia may be present. The nodules tend to break down and may discharge their contents into the bronchioles, resulting in extension of the infection to the upper respiratory tract.

Cutaneous form (farcy)

Nodules appear along the course of the lymph vessels, particularly of the extremities. These nodules degenerate and form ulcers that discharge a highly infectious, sticky pus. The liver and spleen also may show typical nodular lesions.

Diagnosis

The typical nodules, ulcers, scar formation, and debilitated condition may provide sufficient evidence for a clinical diagnosis. However, because these signs usually do not develop until the disease is well advanced, specific diagnostic tests should be used as early as possible.

The mallein test is the procedure of choice. Complement fixation is also accurate, although occasionally a false positive result occurs.

An ELISA has been shown to be more sensitive than complement fixation but has not been widely tested.

Culture of exudate from lesions reveals the presence of the causative organism.

Prevention and Treatment

There is no vaccine. Prevention and control depend on early detection and elimination of affected animals, as well as complete quarantine and rigorous disinfection of the area involved. Treatment is given only in endemic areas.

Antibiotics are not very effective. Combinations of sulfazine or sulfamonomethoxine with trimethoprim were found to be efficient in the prevention and treatment of experimental glanders.

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