The disease of cat scratch( felinosis) - Causes, symptoms and treatment. MF.

One of the list of human infectious diseases that can be infected from an animal is felinosis or cat scratch disease. For the first time described more than 80 years ago the disease for a long time did not have a clear identification with regard to the pathogen, as some or other data on the causes of the illness were cited. And only by 1983, microorganisms were finally identified, "guilty" in the emergence of characteristic symptoms of felinosis, and since 1988 they managed to cultivate them.

Felinosis Felinosis ( from Latin felinus - feline, cat scratch disease or benign lymphoreticulosis, or granuloma Mollyare) is an acute infectious disease that belongs to the bartonellosis group, which has a clear relationship with scratches or bites of cats, manifested by the appearance of a primary focus( affect)or local damage, as well as inflammation of the lymph nodes from the side of the lesion, and rarely the appearance of a general intoxication of the body and the defeat of internal organs. The disease is considered to be not severe and self-sufficient.

infection reservoir A bit of history: benign lymphadenopathy after cat scratches was first described in 1932 by the scientists A.Debre and K.Foshey, then in 1950, V.Mollare and his co-authors repeated the description;to determine the pathogens of the disease at first it was difficult: they considered and viruses, then chlamydia. In 1983, found a gram-negative bacillus, which was called Alipia felis. However, in the subsequent it was not possible to detect it in the blood of patients with felinosis, and there were also no antibodies to it. In this regard, the search for causes continued. A few years later, from the affected lymph nodes, Bartonella henselae was identified, the DNA of which is revealed in the vast majority( 96 and more%) of patients with felinosis.

Causes of "cat scratch disease"

Causes of "cat scratch disease" or felinosis.

The main causative agent of felinosis - Bartonella henselae - gram-negative( in Gram stain it does not stain violet, it is a microbiological concept) of a small bacillus having a different shape( polymorphism).For cultivation, it is quite capricious: it grows slowly - for 10-15 days on special nutrient media with an optimum growth temperature of 35-37º, a certain carbon dioxide ratio of 5-10%, humidity of about 40%.There are two genotypes of the pathogen, but the disease in both cases proceeds in the same manner. The causative agent is unstable to heating, but it maintains low temperatures. Also, the causative agent of felinosis can be Bartonella quintana with similar properties.
In 15% of patients with felinosis, the association of the disease with this pathogen has not been established( it makes sense to think that the role of Alipia felis, discovered earlier in the etiology).

The main reservoir of infection is - infected cats. According to the literature, up to 45-50% of wild and domestic cats are infected, that is, B. henselae is found in the blood. The disease in cats continues for a long time for several years, has a small symptomatology or asymptomatic. It is believed that B. henselae is part of the normal flora of the mouth of cats. The carriers of B. henselae among cats are the cat fleas( Ctenocephalides felis), in the intestinal contents of which the pathogen of the filinosa lives for 9 days from the time of their infection. Direct transfer of B. henselae from fleas to humans is excluded. In the literature, other reservoirs of the pathogen are described - the dog, rodents, monkeys, but cases of human infection are rare. From person to person, the infection is not transmitted.

Mechanism of infection with felinosis - traumatic household contact through the skin and mucous membranes( with bites or scratches of an infected cat).Infected with the saliva of the infected cat, especially when exposed to the mucous membranes of the eyes.

Scratches from cat

Summer-autumn seasonality is characteristic, which is determined by the development cycle of fleas and pathogen.
Population susceptibility is universal, but more often young people fall ill to 18-20 years. Up to 5% of the population have antibodies to B. henselae, which indicates a certain immune stratum of the population, usually it is the owners of cats( up to 25% of the total number of immunized).

Outcomes of infection are associated with the initial state of human immunity. When immunodeficiency can occur a common form of infection, if the immunity is within normal limits, then the symptoms of the disease may be limited to the local process.

After the transferred illness the stable immunity forms.

Symptoms of "cat scratch disease"

In the place of bite or scratch, "primary affect" occurs in 50-55% of patients: dermal elements( papules) are formed, which soon acquire the nature of suppuration. At the same time, inflammatory changes occur in the regional( close) to the primary focal lymph nodes. Histologically, in the lymph nodes there is hyperplasia of cells, the formation of granulomas, abscesses, characteristic "star" necrosis, and sometimes fistulas. Over time, the inflammation resolves, and in place of the granulomas, sclerosing foci are formed. In case of insufficient activity of immunity, the pathogen can penetrate into the blood and spread through the body, and various internal organs( liver, heart, vascular system and others) with development of granulomas like them can be affected.

Clinical forms of "cat scratch disease"

The incubation period( the period from the moment of infection to the onset of symptoms of the disease) in felinosis is on average 1-2 weeks, but it can be shortened to 3 days and extend to 4x6 weeks.
The disease can occur in typical and atypical forms.

A typical form of infection has a certain cyclicity - the presence of three periods:
1) the initial period;
2) the period of the height of the disease;
3) the period of convalescence( recovery).

The initial period of the is characterized by the appearance of the so-called "primary affect" - in place of the
bite or scratches, often after the healing appears exanthema - a rash in the form of papules( small nodule-sized pea) red, not accompanied by itching or painful sensations. In most cases, patients pay no attention to them.

After a while( 2-3 days), the is at its peak : in place of the papules, the festering elements appear which are opened and the crusts appear afterwards. Crusts dry up and fall off, after which there are no defects, no skin pigmentation. This process can last from 1 to 3 weeks.

Primary affect in felinosis

10-14 days after the appearance of papules, inflammatory changes of the lymph nodes appear near the local lesion( regional lymphadenitis): either one or a group of lymph nodes are involved in the process, which increase in size( up to 5 cm, less often up to 10cm in diameter), become painful, compacted. The lymph nodes of the inguinal region, axillary hollows, femoral regions and others become more common. The tissues around the affected lymph node remain unchanged. The defeat of lymph nodes can be prolonged - from 1 week to 2 months. Sometimes this is the only symptom of felinosis. Regional lymphadenitis is accompanied by an increase in temperature of different severity, symptoms of intoxication( weakness, headaches, malaise, sweating).Duration of fever to 2 weeks. With a typical course in the midst of the disease, the liver and spleen may increase.

Axillary lymphadenitis in felinosis

Most cases of felinosis result in spontaneous recovery of : the temperature is normalized, the inflammatory process in the lymph nodes gradually passes, they are sclerosed.

Atypical forms of felinosis:

1) The eye shape of the felineosis , which occurs when the causative agent enters the mucous membrane of the eyes. More often this one-sided defeat in the form of ulcerative-granulomatous conjunctivitis. In patients, the puffiness of the eyelid of the affected eye is expressed, reddening or hyperemia of the eye conjunctiva, the formation of ulcers, granulomas, difficulties with the opening of the eyelid. Parotid and submandibular lymph nodes swell.
2) Neuroretinitis - edema of the optic nerve of one eye, a symptom of a "macular star" - spots of a starlike shape on the retina of the eye, the appearance of nodules on the retina, changes in the vessels of the fundus. In patients with a relatively satisfactory state of health, a visual impairment of one eye.
3) Neurological form of felineosis occurs infrequently. It appears in the form of polyneuritis, radiculitis, neuropathy, myelitis, less often encephalitis, meningitis, the possibility of developing cerebral ataxia. Neurologic disorders appear 2-3 weeks after lymph node involvement.
4) Lesion of the liver and spleen - characterized by the appearance of granulomas in these organs and the development of the inflammatory process in them. In such cases, the patient has several temperature waves, an increase in the liver and spleen, a change in the biochemical parameters of the blood: bilirubin, enzymes - ALT, AST, GGTP, APF.When ultrasound is found hypoechoic foci. Typically, these patients are affected by various groups of lymph nodes( generalized lymphadenopathy).
5) Bacillary angiomatosis ( more often detected in HIV-infected patients).On the skin appear red or purple spots, papules with the subsequent formation of large nodes up to 3 cm in diameter, around the knot "collar" of the erosive epidermis of the skin. Liver, spleen, lymph nodes can also be affected.
6) Other more rare atypical forms include: endocarditis, pleurisy, erythema nodosum, osteomyelitis and others.
The prognosis of the disease is more often favorable and the outcome is recovery.

Diagnosis of felinosis

Preliminary diagnosis is made on the basis of the characteristic symptoms of the disease and epidemiological history( the fact of contact with the cat and disruption of the integrity of the skin or mucous membranes).At this stage it is necessary to make a differential diagnosis( exclude similar diseases): it is necessary to exclude infectious mononucleosis or VEB infection, lymphomas, tularemia, plague. With all these diseases, an increase in the lymph nodes is also observed. For differences, it is necessary to remember the "primary affect" characteristic of felinosis and the increase in its majority only of the regional group of lymph nodes.

The final diagnosis is confirmed by the laboratory tests of .

1) The microbiological method of seeding the material on nutrient media can be used, but the result should be expected from 2 weeks to 1.5 months.
2) Biopsy of inflamed lymph nodes or papule contents, followed by histological examination: granulomatous signs and congestion of bacilli of various forms.
3) Serological diagnosis( detection of antibodies to the pathogen by ELISA) is not available in all regions.
4) PCR diagnostics( detection of the 16S gene by the rabbit B. henselae) in the punctate of the lymph nodes.
5) In the general analysis of blood there is an increase in the number of eosinophils, an increase in ESR.

Treatment of "cat scratch disease"

Therapy in a typical form is performed on an outpatient basis. The infection belongs to the category of self-sufficient( it can pass without treatment), however it can be medicated to help the body to cope with the pathogen faster and to alleviate the symptoms of the disease.

Medication:

• Antihistamines( claritin, zirtek, cetrine, erius and others).
• Nonsteroidal anti-inflammatory drugs for the management of inflammatory reactions( ibuprofen, indomethacin, diclofenac and their modern counterparts).
• Etiotropic therapy includes the prescription of antibacterial drugs: azithromycin, doxycycline and its derivatives, erythromycin and its derivatives, and has also been shown to be effective in the felinosis of ciprofloxacin, rifampicin, bactrim, gentamicin. It is believed that such therapy should be prescribed only in severe forms of infection with the development of atypical forms, as well as in the emergence of felinosis in immunocompromised individuals( HIV infection, chronic diseases, organ and tissue transplant recipients, and others).

When abscesses occur in the area of ​​the lymph nodes, surgical care is required( opening, release from the pus), which affects the duration of healing and sclerosing.

Prevention of felinosis

Prevention is limited to limiting contact with cats. There is no specific prevention.

The doctor infektsionist Bykova N.I.