Bartonella bacillus in humans: where to test, what to treat with

The bacterium Bartonella is a hemotrophic microorganism belonging to the genus of the same name Bartonella, which, in turn, is a representative of the class of alpha-proteobacteria.

The bacterium affects human erythrocytes; in chronic cases, the endothelial tissue of the microcirculation system also suffers. The source of infection can be sick animals (or carriers), most often rodents, dogs, cats or monkeys.

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Structure bartonellae

Bartonella belongs to gram (-) bacteria, under the microscope it looks like a shortened rod, with approximate dimensions of 0.4 by 2 mm. In the section of affected tissues, the bacterium may look curved, small, pleomorphic. Microorganisms tend to gather in small groups (clusters).

Round varieties of Bartonella have diameters of about one and a half millimeters. They can have flagella and a three-layer structure, with a small genome size.

Bartonella reproduces by simple transverse division.

Currently, 25 varieties of Bartonella are known, but only half of them can pose a danger to humans.

The most common Bartonella hensleyi, which causes acute cat scratch disease, lymphadenopathy, and angiomatosis, can be cultured on complex blood media. Bartonella hensleyi is considered an obligate aerobe by its nutritional nature. The bacteria can be acquired through contact with skin lesions or through the mucous membrane of the eye.

Bartonella quintana can cause trench fever or endocarditis. This type of bacteria is transmitted by lice, mice, ectoparasites, and scabies mites.

Bartonella bacilliformis is the cause of Carion's disease. It is spread by mosquitoes and, less commonly, mice.

Bartonella claridgei can cause manifestations of angiomatosis, persistent fever, lymphadenopathy. The bacterium is transmitted through carriers - cats.

Bartonella elizabeth causes inflammation of the endocardium, although the carrier of this type of bacteria has not been identified.

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Life cycle bartonellae

Once in the host's body, Bartonella continues its development over cellular structures, penetrates into erythrocytes and vascular endothelium and the endocardial layer. A typical feature of Bartonella is its ability to activate cellular proliferation of the endothelium and enlargement of capillaries, which can cause excessive proliferation of blood vessels.

The nutritional method of Bartonella is aerobic-hematotrophic. Before entering the mammalian organism, the bacterium can be cultivated inside insects (lice, mosquitoes, fleas), or on a nutrient medium of solid or semi-liquid consistency, with the addition of up to 10% of blood elements.

Bartonella can remain viable in lice secretions for quite a long time – up to 13-12 days. At the same time, the lice do not experience any symptoms from the bacteria.

Bartonella can survive in the bodies of cats or dogs for more than 12 months, and in insects for life.

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Symptoms

The incubation period for infection with Bartonella ranges from 15 to 40 days, less often – up to 90-100 days.

The disease typically progresses in two stages. In the acute period (the so-called Oroya fever stage), the temperature rises to 39° and even 40°C, and the fever does not subside for 2-4 weeks, after which the symptoms slowly subside.

In addition to the feverish state, other symptoms are also observed:

• general intoxication;
• excessive sweating;
• severe pain in the head, muscles, joints, bones;
• sleep disorders;
• delirious and apathetic states;
• loss of appetite;
• dyspepsia.

Hemorrhages may occur on the skin surface. The sclera may be yellow, against the background of an enlarged liver.

In severe cases, the disease can be fatal (in about 20% of patients). The most favorable outcome is expected with the onset of the latent stage, which after 90-180 days transforms into a period of skin rash (the stage of Peruvian warts). This period is characterized by the formation of spots, tubercles, nodules on the skin: this stage can last 8-12 weeks.

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Diagnostics

Diagnostic procedures are performed after the patient is admitted to the infectious diseases department of the hospital.

Often, a Bartonella infection can be suspected if the patient indicates recent contact with an animal (especially if there were scratches or bites).

To confirm the diagnosis, the doctor will definitely prescribe additional tests. For example, you can send blood, tissue elements or discharge from pustules and papules for analysis for Bartonella.

Cultivation of Bartonella on a special nutrient medium is actually difficult and lasts at least 14 days of incubation (sometimes up to one and a half months) before the first isolation. In addition, if the bacteria is not present in the blood, then isolating it becomes even more difficult.

In most cases, the most informative diagnostic test is serology for Bartonella, or more precisely, for its antibodies. There are two ways to conduct a serological test - enzyme immunoassay and fluorescence analysis. If specialists detect IgM antibodies during the study, this indicates an acute course of the pathology. Such antibodies can be in the bloodstream for more than three months from the moment of infection. The IgG antibody type can be determined only 6-7 months after the moment of infection. In about a quarter of patients, IgG antibodies can remain in the bloodstream for more than 12 months.

The main goal of diagnostics is to detect Bartonella in the patient's tissue structures. As a rule, the following main stages of the polymerase chain reaction are used for diagnostics:

• amplification of the 16 S rRNA gene;
• amplification of the citrate synthase gene;
• stimulation of the bacterial HtrA gene.

The analysis for Bartonella is very specific, but infectious disease specialists determine its sensitivity to be about 43-76%. The isolation of Bartonella from the taken elements during the PCR reaction is equivalent to the level of technical isolation of the culture.

In Ukraine, Bartonella testing is carried out by such well-known laboratories as Sinevo and Dila.

In Russia, Helix, a laboratory service, accepts Bartonella tests.

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Treatment

• To treat infection caused by Bartonella, antibiotic therapy is prescribed in all cases:
• taking chloramphenicol 500 mg up to 4 times a day;
• streptomycin injections 500-1000 mg daily;
• taking tetracycline antibiotics 200 mg up to 4 times a day.

During the acute stage of Bartonella, intravenous infusions of novarsenol are successfully used - 300-450 mg once or twice a week.

Additionally, fluoroquinolone drugs may be prescribed - for example, tarivid 200 mg twice a day as an intravenous infusion (for 4 days), followed by oral administration of the drug (for a week).

As an adjuvant treatment, it is appropriate to use blood transfusions, antianemic drugs, and medications to support liver function. Such drugs are often combined with vitamin therapy (tocopherol, ascorbic acid, cyanocobalamin, folic acid), taking cytochrome-C, cyto-MAC, etc.

In case of infection of skin rashes, antiseptic solutions and antibacterial ointments, proteolytic enzyme preparations are prescribed.

Prevention bartonellae

Preventive measures include limiting personal contact with rodents, stray cats and dogs, and not allowing them into the house. In case of accidental contact, wash your hands with laundry soap, under a sufficient amount of running water. If there are scratches and abrasions on the skin, treat them with a solution of hydrogen peroxide or any alcohol solution.

Prophylactic use of antibiotics is considered inappropriate, as is prophylactic treatment of animals.

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Forecast

In most cases, the prognosis for patients with Bartonella infection is relatively good, unless the patient does not receive medical care for some reason. Signs of infection can sometimes persist for several months, with complications developing only in extreme cases. After proper antibiotic therapy, Bartonella is eliminated without a trace, without relapses.

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