Brucellosis of the eye

Brucellosis (Bang's disease, Malta fever, melitococcus) is a common infectious-allergic disease belonging to the group of zoonoses.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ], [ 8 ]

Causes and epidemiology of brucellosis of the eye

The causative agent of brucellosis is bacteria of the Brucella type. For humans, Br. melitensis is the most pathogenic. Infection occurs through contact with sick animals (goats, sheep, cows, pigs), through the use of infected dairy and contaminated meat products. Wool, leather, karakul, and contaminated excrements of sick animals are dangerous. People with brucellosis are not carriers of the infection. The entry points for brucellosis can be the skin if there are abrasions, small wounds, mucous membranes of the digestive tract and respiratory tract, i.e. the infection is transmitted by alimentary, contact and airborne routes.

Pathogenesis of brucellosis of the eye

Brucella, penetrating the body, first enter the regional lymph nodes, and from there into the blood. From the bloodstream, they settle in the organs of the reticuloendothelial system (liver, spleen, bone marrow, lymph nodes), where they can remain intracellular for a long time. During exacerbations of the process, brucellae again multiply rapidly, enter the bloodstream, causing repeated waves of generalization. In the pathogenesis of brucellosis manifestations, allergic reactions play a significant role, which can be observed from the 2nd-3rd week of the disease. Changes in the organ of vision in brucellosis occur during the dissemination of brucellae from the primary focus to already sensitized tissues of the eye or during super- or reinfection, as well as during infection of vaccinated people.

Symptoms of brucellosis of the eye

The incubation period lasts 1-3 weeks, sometimes several months. Significant polymorphism of clinical manifestations of brucellosis is noted. The disease can occur in the form of acute, chronic brucellosis and in a latent form.

Acute brucellosis is characterized by the absence of focal lesions. Acute brucellosis is characterized by an increase in body temperature, chills, profuse sweating with a satisfactory general condition. Only from the 2nd week of the disease does hepatosplenic syndrome develop.

Chronic brucellosis is characterized by a variety of clinical manifestations caused by damage to various organs and systems, a recurring course over many years. Typical lesions are the musculoskeletal system (arthralgia, arthritis, bursitis, spondylitis, etc.), the central nervous system (functional disorders, meningomyelitis, meningitis, encephalitis, meningoencephalitis), liver, spleen and other organs. Eye disease mainly occurs in chronic and latent brucellosis. At the same time, patients may feel clinically healthy, remaining carriers of the infection, which, under the influence of unfavorable factors (hypothermia, fatigue, colds), can cause damage to the uveal tract, optic nerve, cornea. More often with brucellosis, uveitis is observed, which is metastatic or toxic-allergic in nature. The clinical picture of brucellosis uveitis does not have any specific features.

The following forms of brucellosis uveitis are distinguished:

1. exudative iritis;
2. anterior exudative choroiditis;
3. metastatic ophthalmia;
4. nodular iritis;
5. disseminated chorioretinitis;
6. central chorioretinitis;
7. total uveitis.

The most common form of brucellosis uveitis is exudative iridocyclitis. It can be acute or chronic, with relapses, sometimes over many years. The process is usually unilateral. In the clinical picture, along with typical signs of iridocyclitis, folds of Descemet's membrane are often observed. On the back surface of the cornea, in addition to the usual precipitates, coarser exudate deposits in the form of lumps, sometimes hypopyon, may appear. In chronic iridocyclitis or relapses, newly formed vessels, coarse posterior synechiae, and even fusion and overgrowth of the pupil develop in the iris. In such cases, secondary glaucoma and cataracts occur. In severe cases, panuveitis may develop, ending in atrophy of the eyeball.

Anterior exudative choroiditis is characterized by opacity of the vitreous body of varying intensity without visible changes in the anterior part of the eye and fundus. Choroiditis can be focal or diffuse. Brucellosis choroiditis is characterized by the presence of foci with weak perifocal edema. Ophthalmic forms of brucellosis uveitis are observed much less frequently. Individual cases of brucellosis keratitis in the form of superficial coin-shaped, deep or phlyctene-like are described.

Nummular keratitis is characterized by the appearance of yellowish infiltrates located over the entire surface of the cornea. With timely treatment, the infiltrates can completely resolve or undergo disintegration and ulceration due to secondary infection. Deep brucellosis keratitis is often unilateral, has a recurrent course with the localization of the main focus in the center, the presence of folds of Descemet's membrane, precipitates. At first, the process is avascular, then minor vascularization occurs. Changes in the cornea in brucellosis do not have any specific picture, and diagnosis is possible using serological reactions.

In chronic brucellosis against the background of meningitis, meningoencephalitis, acute bilateral retrobulbar neuritis may develop. The clinical picture of brucellosis retrobulbar neuritis does not differ from neuritis of other etiologies and is characterized by a violation of visual functions. In brucellosis, changes in the optic nerve are described in the form of papillitis in the absence of changes in the central nervous system. Sometimes papillitis is combined with uveitis.

Diagnostics of brucellosis lesions of the visual organ

The polymorphism of the clinical picture and the stereotypical nature of the course of a number of infectious diseases make it difficult to diagnose brucellosis. Eye changes in brucellosis are also non-specific. Every patient with uveitis, neuritis, keratitis of cingulate etiology who has consulted an ophthalmologist must be examined for brucellosis in the department of especially dangerous infections at republican, regional, territorial sanitary and epidemiological stations. Establishing the fact of brucellosis infection does not yet mean recognizing the brucellosis etiology of the eye process. A comprehensive examination of the patient and exclusion of any other etiology of the eye disease (tuberculosis, leptospirosis, toxoplasmosis, syphilis, etc.) are necessary.

In diagnosing brucellosis and its ocular manifestations, bacteriological and serological methods of research are of decisive importance: the Wright and Huddleson agglutination reaction, the passive hemagglutination reaction (RPGA) and the Burnet skin-allergic test. In brucellosis, the bacteriological method of diagnosis is reliable - the isolation of brucellae from blood, urine, cerebrospinal fluid, fluid of the anterior chamber of the eye, etc.

The Wright agglutination test is one of the main diagnostic methods for acute forms of brucellosis. It becomes positive early after infection. A titer of agglutinins in the serum being tested of at least 1:200 is considered diagnostically reliable.

The generally accepted method of rapid diagnostics of brucellosis is the Huddleson plate agglutination test. The reaction is specific, positive in the early period and persists for a long time.

RPGA is highly sensitive and specific for brucellosis infection. It allows to detect antibodies not only in patients, but also in the serum of people who have had contact with the source of infection. It is considered positive starting from a dilution of 1:100. The Coombs reaction is widely used to diagnose chronic forms of brucellosis - the determination of incomplete antibodies.

The skin-allergic test is based on the ability of the organism, sensitized by the brucellosis allergen, to respond with a local reaction to the intradermal administration of brucellin. The test becomes positive in 70-85% of cases by the end of the first month of the disease (but there are cases of earlier onset) and remains so for a very long time. It can be positive during the latent period of the disease and in vaccinated people. When examining patients for brucellosis, it is necessary to take into account that the allergen is introduced during the skin-allergic test, therefore, to conduct the agglutination reaction, blood must be taken before the skin-allergic test. Serological reactions and the skin-allergic test are not equivalent in their diagnostic value at different periods of the disease, which determines the use of a complex of the seroallergic method for diagnosing brucellosis.

[ 9 ], [ 10 ], [ 11 ], [ 12 ], [ 13 ], [ 14 ]

Treatment of brucellosis of the eye

Treatment of patients with brucellosis of the eye in the presence of signs of process activity is carried out in an infectious diseases hospital under the supervision of an ophthalmologist. Patients with chronic brucellosis can be hospitalized in any department depending on the clinical manifestations. In the acute period, long-term (up to 1 month) use of various antibiotics (except penicillin) in therapeutic doses is indicated. However, antibiotics do not act on brucellae located intracellularly and do not prevent relapses, so they can be prescribed only in the presence of bacteremia. In the treatment of brucellosis, hemodez, brucellosis gamma globulin, polyglucin, rheopolyglucin, vitamins (especially C and group B) are widely used. In chronic forms, when eye disease is more often observed, the main method of treatment is vaccine therapy. Brucellosis vaccine is used intradermally, subcutaneously, intramuscularly or intravenously, strictly individually. The first dose of the vaccine is administered depending on the results of the skin allergy test. The interval between injections depends on the post-vaccination reaction: if the reaction is strong, the dose is repeated or even reduced, if it is weak, on the contrary, it is increased, and the interval is reduced. The course of treatment is 8-12 injections of the vaccine. Contraindications for treatment with the vaccine are chronic diseases of the central nervous system, heart, etc. In the relapse phase of the chronic form of brucellosis, the use of corticosteroids is pathogenetically justified. Local treatment for uveitis is reduced to the administration of mydriatics, corticosteroids, enzymes, desensitizing agents. In case of optic neuritis of brucellosis genesis, in addition to specific therapy, it is advisable to use dehydrating, vasodilators, corticosteroids according to indications.

Prevention of brucellosis

Prevention of brucellosis involves eliminating sources of infection (curing brucellosis in animals, disinfecting animal care items, products and raw materials of animal origin), and vaccinating individuals at risk of infection.

Prevention of brucellosis of the eyes consists of early diagnosis of brucellosis and timely treatment.

Working capacity in case of brucellosis of the visual organ is determined by the clinical form of the disease, the state of vision, and damage to other organs and systems. In case of uveitis, neuritis, and keratitis of brucellosis etiology, due to the tendency to recurrence, the prognosis for vision remains serious.