Characteristics of syphilis. Etiology. Conditions and routes of infection with syphilis. Experimental syphilis. General course of syphilis. Syphilis in animals Syphilis in animals

Reinfection is re-infection. It is important to know for sure that the patient has recovered after the first infection. A number of signs indicate reinfection:

1. During reinfection, the location of the developing primary syphiloma is far from the site of localization of the chancre during the first infection.
2. Typical picture of newly developing primary syphiloma.
3. The presence of pale spirochetes in the lesion.
4. Development of fresh regional bubo.
5. The transition from negative serological reactions to positive ones at the beginning of the development of primary syphiloma.
6. Reliability of a previous infection and thorough treatment of it in the past.
7. Absence of recurrent rash.
8. Diagnosis of syphilis in a partner (i.e., confrontation).

There is no innate immunity to syphilis in humans. Those who have recovered from syphilis also do not have strong immunity and may become infected again (reinfection).
In the body of a patient with syphilis, non-sterile infectious immunity develops, which occurs 10-14 days after the appearance of chancre. And while Treponema pallidum is in the patient’s body, he is practically not susceptible to new infection. Immunity exists as long as the pathogen is present in the body and disappears as soon as recovery occurs.

Nonsterile immunity is accompanied by an allergic reaction. With the disappearance of infectious immunity, infectious allergies disappear. Consequently, with syphilis, the body’s reactivity changes in two directions: increased (allergy) and decreased (immunity).
The most important factor of immunity is phagocytosis, in which macrophages and histiocytes capture the treponema surrounded by a lymphocyte, and part of it passes into the lymphocyte, which becomes sensitized to these antigens. In response to the presence of treponema in the body, immunoglobulin antibodies are formed: IgM (reagins), IgG (immobilisins), IgA (fluoresceins).

Immunity in syphilis is not passively transmitted, although specific antibodies to the pale spirochete (agglutinins, lysines) were found in the serum of a patient with syphilis.

Superinfection is the layering of an additional mass of pale spirochete onto those existing in the body. During the incubation period and in the first 10-14 days of the primary period of syphilis, when infectious immunity has not formed, additional infection is manifested by the development of a new chancre. It is smaller in size and arose after a shortened incubation period Such chancres are called sequential. In the secondary period, a papule or pustule appears at the site of infection, in the tertiary period, a tubercle or gumma appears.

EXPERIMENTAL SYPHILIS

Long before the discovery of Treponema pallidum, scientists made attempts to infect animals with syphilis. Now it is difficult to establish who was the first to do this, since the animal clinic was not supported by the discovery of the pathogen.
I.I. Mechnikov and Roux successfully inoculated two chimpanzees with syphilis in 1903. The first experiments on infecting a rabbit in the eye are attributed to Jense (1881); Bertarelli (1906) infected a rabbit with syphilis by rubbing it into a scratch on the cornea of ​​the eye. In 1907, Parodi first infected a rabbit by injecting material from a syphilitic papule under the tunica vaginalis.
Currently, the rabbit is the main animal for experiments to obtain experimental syphilis. Animals are infected with a suspension of pale treponema, extracted from syphilitic manifestations, by introducing intratesticularly (early orchitis), intradermally on the scrotum (receiving chancre), on the side into the shaved surface of the skin, by rubbing into the scarified surface of the skin or intradermally, into the anterior chamber of the eye, suboccipitally, into the brain.
After an incubation period (2-3 weeks), a small compaction appears at the site of administration of Treponema pallidum, gradually increasing in size and acquiring a cartilaginous consistency. Necrosis and chancre, covered with a small bloody crust, form in its center. A huge amount of treponema is found in the chancre contents. There are no inflammatory phenomena along the periphery of the chancre. After about 3-4 weeks, the chancre softens and the number of treponemas decreases. Serological reactions become positive, their titer gradually increases.
Simultaneously with the chancre, regional lymph nodes up to the size of a pea are palpated in the rabbit. 2.5-3 months after the formation of chancre, the animal may
Secondary manifestations may occur (papular, papulocrustal, rupee-shaped rashes), in the contents of which pale treponema is found. Roseolas do not appear. The percentage of occurrence of secondary manifestations in rabbits varies. Most often, secondary manifestations are localized in the skin of the scrotum, limbs, roots of the ears, and superciliary arches. The secondary period of syphilis in rabbits is characterized by baldness. The development of parenchymal keratitis is also observed, the number of which varies depending on the time of year.
The manifestation of the tertiary period of syphilis is very rare. There is no convincing evidence of damage to the nervous system yet. Involvement of the internal organs of rabbits in the pathological process is observed: aortitis, changes in the liver, etc. (L. S. Zenin, 1929; S. L. Gogaishis, 1935). There are isolated reports in the literature (P.S. Grigoriev, K.G. Yarysheva, 1928) about successful experiences of obtaining congenital syphilis from them. Sometimes, when infected with treponema pallidum, rabbits do not develop any signs of illness or there are no clinical manifestations if the pathogen is present in the lymph nodes or internal organs (such rabbits are called nullers - they have infectious immunity to syphilis).
The therapeutic effectiveness of drugs is being studied using an experimental model of syphilis.
In recent years, reports have appeared that after immunizing rabbits with treponemal vaccines, it was possible to obtain protection from subsequent infection of these animals with a suspension of pathogenic treponema pallidum. However, these results were not confirmed by N. M. Ovchinnikov et al.

We do not have the opportunity to list and analyze here all domestic work on experimental syphilis. We will only point out the work carried out by the Leningrad school - M. V. Veksel, A. Ya. Vilenchuk, S. E. Gorbavitsky, P. G. Oganesyan, S. T. Pavlov and others; Moscow school - P. S. Grigoriev, V. A. Rakhmanov, M. A. Rozentul, Yu. A. Finkelshtein and others; Odessa school - G. I. Boevskaya, M. M. Israel, I. D. Perkel and others.

Syphilis- a chronic infectious disease that occurs when infected with Treponema pallidum. Infection occurs predominantly through sexual contact, but transmission is possible transplacentally (congenital syphilis), through household contact (domestic syphilis) and through blood transfusion (blood transfusion).

Etiology

The causative agent of syphilis is Treponema pallidum, which belongs to the order Spirochaetales, family Spirochaetaceae, genus Treponema. Morphologically, treponema pallidum (pale spirochete) differs from saprophytic spirochetes (Spirochetae buccalis, Sp. refringens, Sp. balanitidis, Sp. pseudopallida). Under a microscope, Treponema pallidum is a spiral-shaped microorganism that resembles a corkscrew. It has on average 8-14 uniform curls of equal size. The total length of the treponema varies from 7 to 14 microns, thickness - 0.2-0.5 microns. Treponema pallidum is characterized by pronounced mobility, in contrast to saprophytic forms. It is characterized by translational, rocking, pendulum-like, contractile and rotatory (around its axis) movements. Using electron microscopy, the complex morphological structure of Treponema pallidum was revealed. It turned out that the treponema is covered with a thick cover of a three-layer membrane, a cell wall and a mucopolysaccharide capsule-like substance. Under the cytoplasmic membrane there are fibrils - thin filaments that have a complex structure and cause diverse movement. Fibrils are attached to the terminal turns and individual sections of the cytoplasmic cylinder using blepharoplasts. The cytoplasm is finely granular, containing a nuclear vacuole, nucleolus and mesosomes. It was established that various influences of exo- and endogenous factors (in particular, previously used arsenic preparations, and currently antibiotics) had an impact on Treponema pallidum, changing some of its biological properties. Thus, it turned out that pale treponema can turn into cysts, spores, L-forms, grains, which, when the activity of the patient’s immune reserves decreases, can reverse into spiral-shaped virulent varieties and cause active manifestations of the disease. The antigenic mosaic nature of Treponema pallidum has been proven by the presence of multiple antibodies in the blood serum of patients with syphilis: protein, complement-fixing, polysaccharide, reagin, immobilisin, agglutinin, lipoid, etc.

Using an electron microscope, it was found that treponema pallidum in lesions is most often located in intercellular spaces, periendothelial space, blood vessels, nerve fibers, especially in early forms of syphilis. The presence of pale treponema in the periepineurium is not yet evidence of damage to the nervous system. More often, such an abundance of treponemes occurs during septicemia. During the process of phagocytosis, a state of endocytobiosis often occurs, in which treponemes in leukocytes are enclosed in a multimembrane phagosome. The fact that treponemes are enclosed in polymembrane phagosomes is a very unfavorable phenomenon, since, being in a state of endocytobiosis, treponema pallidums persist for a long time, protected from the effects of antibodies and antibiotics. At the same time, the cell in which such a phagosome has formed seems to protect the body from the spread of infection and progression of the disease. This precarious balance can persist for a long time, characterizing the latent (hidden) course of a syphilitic infection.

Experimental observations by N.M. Ovchinnikov and V.V. Delectorsky are consistent with the works of the authors who believe that when infected with syphilis, a long-term asymptomatic course is possible (if the patient has L-forms of Treponema pallidum in the body) and “accidental” detection of infection in the stage of latent syphilis (lues latens seropositiva, lues ignorata), i.e. i.e. during the period of presence of treponema in the body, probably in the form of cyst forms, which have antigenic properties and, therefore, lead to the production of antibodies; this is confirmed by positive serological reactions to syphilis in the blood of patients without visible clinical manifestations of the disease. In addition, in some patients, stages of neuro- and viscerosyphilis are detected, i.e., the disease develops as if “bypassing” the active forms.

To obtain a culture of Treponema pallidum, complex conditions are required (special media, anaerobic conditions, etc.). At the same time, cultural treponemes quickly lose their morphological and pathogenic properties. In addition to the above forms of treponema, the existence of granular and invisible filterable forms of pale treponema was assumed.

Outside the body, treponema pallidum is very sensitive to external influences, chemicals, drying, heating, and exposure to sunlight. On household items, Treponema pallidum retains its virulence until it dries. A temperature of 40-42°C first increases the activity of treponemes and then leads to their death; heating to 60°C kills them within 15 minutes, and to 100°C kills them instantly. Low temperatures do not have a detrimental effect on treponema pallidum, and currently, storing treponemes in an oxygen-free environment at temperatures from -20 to -70 ° C or frozen dried is a generally accepted method for preserving pathogenic strains.

Conditions and routes of infection with syphilis

The causative agent of syphilis, Treponema pallidum, enters the human body through damaged skin or mucous membranes. The entrance gate through which the syphilis pathogen enters may be so insignificant that it goes unnoticed by the examiner. A patient with syphilis is contagious to others, especially during the period of active manifestations of the infection, on the surface of which pallid treponema are “washed out” along with serum from the depths of the tissues due to friction (during walking), friction (during sexual intercourse), irritation (mechanical or chemical) , as well as with food (if syphilitic papules are found in the oral cavity).

Currently, the main route of infection with syphilis should be recognized as sexual contact between a patient and a healthy person; cases of household contamination (when using shared utensils, cigarettes, pipes, etc.) are rare. Extrasexual infection can occur if there are eroded syphilitic elements in the patient’s mouth. Much less frequently, cases are observed when treponemes found in the discharge of syphilitic elements end up on household items, which become an intermediary in the transmission of infection (in a humid environment, treponemas remain viable for a long time outside the human body). Doctors and other medical personnel can become infected when examining a patient with syphilis or during treatment procedures. Such cases were observed among midwives, surgeons, obstetricians-gynecologists, dentists, venereologists, and laboratory workers who conducted research on Treponema pallidum. To avoid such infection, you need to work with the patient wearing gloves, monitor the integrity of the skin of the hands, and after examining the patient (especially with the contagious stage of syphilis), wipe your hands with a disinfectant solution and wash them with soap.

Cases of infection with syphilis through direct blood transfusion from a donor with syphilis are very rare. It is believed that the patient’s saliva is infectious due to the presence of Treponema pallidum in it only if the patient has syphilitic elements in the oral cavity. It has been suggested that the milk of a nursing woman with syphilis is contagious, even if there are no visible syphilitic changes in the area of ​​the breast.

The question of the contagiousness of sperm is also interpreted, despite the absence of manifestations of the disease on the genitals of a patient with active syphilis. At the same time, it is believed that the urine and sweat of patients with syphilis are not contagious. One of the possible routes of transmission of syphilitic infection is placental: from a sick mother to the fetus through the placenta. As a result, congenital syphilis may develop.

It has been experimentally established that the amount of pathogen introduced into the body of the experimental animal also plays a role in the development of syphilitic infection. It can be assumed that this also has a certain significance in people (therefore, in persons who have repeatedly had sexual contact with a patient with active form of syphilis, the possibility of infection is much greater compared to those who have had a single and short-term sexual relationship). At the same time, the lack of infection criteria forces venereologists to carry out preventive treatment to all persons who have had sexual contact with a patient with an infectious form of syphilis, as well as to those persons (especially children) who were in close household contact.

Experimental syphilis

Attempts to infect various animals with syphilis in order to create an experimental model of infection (to study issues of etiology, pathogenesis, therapy, etc.) were made back in the last century. However, the first experiments on experimental infection of animals with syphilis, which received universal recognition, were carried out by I.I. Mechnikov and Roux in 1903. The authors not only successfully infected two chimpanzees with syphilis, but also observed the development of manifestations of the secondary period of the disease (papules on the abdomen and limbs).

Pathogenesis

The reaction of the patient's body to the introduction of Treponema pallidum is complex, diverse and insufficiently studied. Infection occurs as a result of penetration of Treponema pallidum through the skin or mucous membrane, the integrity of which is usually compromised. However, a number of authors admit the possibility of the introduction of treponema through an intact mucous membrane. At the same time, it is known that in the blood serum of healthy individuals there are factors that have immobilizing activity against Treponema pallidum. Along with other factors, they make it possible to explain why infection is not always observed upon contact with a sick person.

Syphilis is a classic venereal disease. Syphilis in men, women and children at different stages is characterized by such signs as damage to the skin, mucous membranes, internal organs (cardiovascular system, stomach, liver), osteoarticular and nervous systems.

Symptoms of the disease, among other manifestations, may include:

• fever (temperature);

The causative agent - treponema pallidum, or pale spirochete - was discovered in 1905. "Pale" - because it is almost not stained with the usual aniline dyes used for this purpose in microbiology. Treponema pallidum has a spiral shape, resembling a long, thin corkscrew.

Stages of syphilis

Syphilis is a very long-term disease. A rash on the skin and mucous membranes gives way to periods when there are no external signs and the diagnosis can be made only after a blood test for specific serological reactions. Such latent periods can drag on for a long time, especially in the later stages, when, in the process of long-term coexistence, the human body and Treponema pallidum adapt to each other, achieving a certain “equilibrium.” Manifestations of the disease do not appear immediately, but after 3-5 weeks. The time preceding them is called incubation: bacteria spread through the flow of lymph and blood throughout the body and multiply quickly. When there are enough of them, and the first signs of the disease appear, the stage of primary syphilis begins. Its external symptoms are erosion or ulcer (hard chancre) at the site of infection entering the body and enlargement of nearby lymph nodes, which disappear without treatment after a few weeks. 6-7 weeks after this, a rash appears that spreads throughout the body. This means that the disease has entered the secondary stage. During this period, rashes of various types appear and, after existing for some time, disappear. The tertiary period of syphilis occurs after 5-10 years: nodes and tubercles appear on the skin.

Symptoms of primary syphilis

Hard chancre (ulcers), one or more, are most often located on the genitals, in places where microtraumas usually occur during sexual intercourse. In men, this is the head, foreskin, and less commonly, the shaft of the penis; sometimes the rash may be located inside the urethra. In homosexuals, they are found in the circumference of the anus, in the depths of the folds of skin that form it, or on the mucous membrane of the rectum. In women, they usually appear on the labia minora and majora, at the entrance to the vagina, on the perineum, and less often on the cervix. In the latter case, the ulcer can only be seen during a gynecological examination on a chair using mirrors. Chancres can practically appear anywhere: on the lips, in the corner of the mouth, on the chest, lower abdomen, on the pubis, in the groin, on the tonsils, in the latter case resembling a sore throat, in which the throat hardly hurts and the temperature does not rise. Some patients develop thickening and swelling with severe redness, even bluing of the skin, in women - in the labia majora, in men - in the foreskin. With the addition of a “secondary”, i.e. additional infection, complications develop. In men, this is most often inflammation and swelling of the foreskin (phimosis), where pus usually accumulates and you can sometimes feel a lump at the site of an existing chancre. If, during the period of increasing swelling of the foreskin, it is moved back and the head of the penis is opened, then the reverse movement is not always successful and the head ends up pinched by the sealed ring. It swells and if not released, it may become dead. Occasionally, such necrosis (gangrene) is complicated by ulcers of the foreskin or located on the head of the penis. About a week after the appearance of chancre, nearby lymph nodes (most often in the groin) painlessly enlarge, reaching the size of a pea, plum, or even a chicken egg. At the end of the primary period, other groups of lymph nodes also increase.

Symptoms of secondary syphilis

Secondary syphilis begins with the appearance of a profuse rash throughout the body, which is often preceded by a deterioration in health, and the temperature may rise slightly. The chancre or its remains, as well as enlarged lymph nodes, are still preserved by this time. The rash usually appears as small pink spots that evenly cover the skin, do not rise above the surface of the skin, do not itch or peel. This kind of spotty rash is called syphilitic roseola. Since they do not itch, people who are inattentive to themselves can easily overlook it. Even doctors can make a mistake if they have no reason to suspect a patient has syphilis, and diagnose measles, rubella, scarlet fever, which are now often found in adults. In addition to roseola, there is a papular rash, consisting of nodules the size of a match head to a pea, bright pink, with a bluish, brownish tint. Much less common are pustular, or pustular, similar to common acne, or a rash with chicken pox. Like other syphilitic rashes, pustules do not hurt. The same patient may have spots, nodules, and pustules. The rashes last from several days to several weeks, and then disappear without treatment, only to be replaced by new ones after a more or less long time, opening a period of secondary recurrent syphilis. New rashes, as a rule, do not cover the entire skin, but are located in separate areas; they are larger, paler (sometimes barely noticeable) and tend to cluster together to form rings, arcs and other shapes. The rash can still be macular, nodular or pustular, but with each new appearance the number of rashes becomes smaller and the size of each of them larger. For the secondary relapse period, nodules on the external genitalia, in the perineal area, near the anus, and under the armpits are typical. They enlarge, their surface becomes wet, forming abrasions, the weeping growths merge with each other, resembling cauliflower in appearance. Such growths, accompanied by a fetid odor, are little painful, but can interfere with walking. Patients with secondary syphilis have so-called “syphilitic tonsillitis,” which differs from the usual one in that when the tonsils become red or whitish spots appear on them, the throat does not hurt and the body temperature does not rise. Whitish flat formations of oval or bizarre shapes appear on the mucous membrane of the neck and lips. On the tongue there are bright red areas of oval or scalloped outlines, in which there are no papillae of the tongue. There may be cracks in the corners of the mouth - so-called syphilitic jams. Brownish-red nodules sometimes appear on the forehead - the “crown of Venus”. Purulent crusts may appear around the mouth, simulating ordinary pyoderma. A rash on the palms and soles is very common. If any rashes appear in these areas, you should definitely check with a venereologist, although skin changes here may also be of a different origin (for example, fungal). Sometimes small (the size of a little fingernail) rounded light spots, surrounded by darker areas of skin, form on the back and sides of the neck. "Necklace of Venus" does not peel and does not hurt. There is syphilitic baldness (alopecia) in the form of either uniform hair thinning (up to pronounced) or small numerous patches. It resembles moth-eaten fur. Eyebrows and eyelashes often also fall out. All these unpleasant phenomena occur 6 or more months after infection. An experienced venereologist only needs a quick glance at the patient to diagnose him with syphilis based on these signs. Treatment quickly leads to restoration of hair growth. In weakened patients, as well as in patients who abuse alcohol, there are often multiple ulcers scattered throughout the skin, covered with layered crusts (the so-called “malignant” syphilis. If the patient is not treated, then several years after infection he may enter the tertiary period.

Symptoms of tertiary syphilis

Single large nodes up to the size of a walnut or even a chicken egg (gumma) and smaller ones (tubercles), located, as a rule, in groups, appear on the skin. The gumma gradually grows, the skin becomes bluish-red, then a viscous liquid begins to be released from its center and a long-term non-healing ulcer with a characteristic yellowish bottom of a “greasy” appearance is formed. Gummous ulcers are characterized by a long existence, lasting for many months and even years. Scars, after they have healed, remain for life, and from their typical star-shaped appearance one can understand after a long time that this person had syphilis. Tubercles and gummas are most often located on the skin of the anterior surface of the legs, in the area of ​​the shoulder blades, forearms, etc. One of the common sites of tertiary lesions is the mucous membrane of the soft and hard palate. Ulcerations here can reach the bone and destroy bone tissue, the soft palate, wrinkle with scars, or form holes leading from the oral cavity to the nasal cavity, causing the voice to acquire a typical nasal tone. If gummas are located on the face, they can destroy the bones of the nose, and it “falls through.” At all stages of syphilis, internal organs and the nervous system can be affected. In the first years of the disease, some patients develop syphilitic hepatitis (liver damage) and manifestations of “latent” meningitis. With treatment they go away quickly. Much less often, after 5 or more years, compactions or gumma, similar to those that appear on the skin, sometimes form in these organs. The aorta and heart are most often affected. A syphilitic aortic aneurysm is formed; in some part of this vital vessel, its diameter sharply expands, and a sac with very thin walls (aneurysm) is formed. A rupture of an aneurysm leads to instant death. The pathological process can also “slide” from the aorta to the mouths of the coronary vessels that supply the heart muscle, and then attacks of angina occur, which are not relieved by the means usually used for this. In some cases, syphilis causes myocardial infarction. Already in the early stages of the disease, syphilitic meningitis, meningoencephalitis, a sharp increase in intracranial pressure, strokes with complete or partial paralysis, etc. can develop. These severe phenomena are very rare and, fortunately, respond quite well to treatment. Late lesions (tabes dorsalis, progressive paralysis). They occur if a person has not been treated or was treated poorly. With tabes dorsalis, treponema pallidum affects the spinal cord. Patients suffer from attacks of acute excruciating pain. Their skin loses sensitivity so much that they may not feel the burn and pay attention only to the damage to the skin. The gait changes, becomes “duck-like”, first there is difficulty urinating, and then urinary and fecal incontinence. Damage to the optic nerves is especially severe, leading to blindness in a short time. Severe deformities of large joints, especially the knees, may develop. Changes in the size and shape of the pupils and their reaction to light are detected, as well as a decrease or complete disappearance of tendon reflexes, which are caused by hitting the tendon below the knee (patellar reflex) and above the heel (Achilles reflex) with a hammer. Progressive paralysis usually develops after 15-20 years. This is irreversible brain damage. A person’s behavior changes sharply: ability to work decreases, mood fluctuates, the ability to self-criticize decreases, either irritability, explosiveness, or, conversely, unreasonable cheerfulness and carelessness appear. The patient sleeps poorly, often has a headache, his hands tremble, and his facial muscles twitch. After some time, he becomes tactless, rude, lustful, and displays a tendency to cynical abuse and gluttony. His mental abilities are fading, he loses his memory, especially for recent events, the ability to count correctly during simple arithmetic operations “in his head”, when writing he misses or repeats letters, syllables, his handwriting becomes uneven, sloppy, his speech is slow, monotonous, as if " stumbling." If treatment is not carried out, he completely loses interest in the world around him, soon refuses to leave his bed, and with symptoms of general paralysis, death occurs. Sometimes with progressive paralysis, delusions of grandeur occur, sudden attacks of excitement, aggression that are dangerous to others.

Diagnosis of syphilis

Diagnosis of syphilis is based on the evaluation of blood tests for syphilis.
There are many types of blood tests for syphilis. They are divided into two groups:
non-treponemal (RPR, RW with cardiolipin antigen);
treponemal (RIF, RIBT, RW with treponemal antigen).
For mass examinations (in hospitals, clinics), non-treponemal blood tests are used. In some cases, they can be false positive, that is, they can be positive in the absence of syphilis. Therefore, a positive result of non-treponemal blood tests must be confirmed by treponemal blood tests.
To assess the effectiveness of treatment, quantitative non-treponemal blood tests are used (for example, RW with cardiolipin antigen).
Treponemal blood tests remain positive after syphilis for life. Therefore, treponemal blood tests (such as RIF, RIBT, RPGA) are NOT used to assess the effectiveness of treatment.

Treatment of syphilis

Treatment of syphilis is carried out only after the diagnosis has been established and confirmed by laboratory research methods. Treatment of syphilis should be comprehensive and individual. Antibiotics are the mainstay of treatment for syphilis. In some cases, treatment is prescribed that complements antibiotics (immunotherapy, restorative drugs, physiotherapy, etc.).

Remember! It is dangerous to self-medicate syphilis. Recovery is determined only by laboratory methods.

Complications of syphilis

An insane number of problems arise in a person who has survived to tertiary syphilis, which is already difficult to treat and can lead to death. A sick pregnant woman will transmit the infection to her child in utero. Congenital syphilis is a severe condition.

Treponema pallidum enters the human body through damaged skin or mucous membranes. Entrance gates can be so small that they go unnoticed. A person with syphilis is contagious to others, especially with active manifestations of the infection. Treponema pallidums can come to the surface with serous fluid from the depths of the tissues due to friction (during walking), friction (during sexual intercourse), irritation (mechanical or chemical), as well as from the oral cavity if syphilitic papules are found there.

Currently, sexual contact should be recognized as the main route of infection with syphilis. Cases of household infection (through dishes, cigarettes, pipes, etc.) are rare. Extrasexual infection is possible if there are eroded syphilitic elements in the patient’s mouth. Much less often, the discharge of syphilitic elements ends up on household items, which become intermediaries

nothing in the transmission of infection (in a humid environment, treponemes remain viable for a long time outside the human body). Health care workers can become infected when examining a patient with syphilis or during medical procedures. Such cases were observed among midwives, surgeons, obstetricians-gynecologists, dentists, venereologists, and laboratory workers who conducted research on Treponema pallidum. To avoid such infection, you need to work with gloves, monitor the integrity of the skin of your hands, and after examining the patient (especially with the contagious stage of syphilis), remove your gloves, wipe your hands with a disinfectant solution and wash them with soap.

Cases of infection with syphilis through direct blood transfusion from a donor with syphilis are very rare. It is believed that the patient’s saliva is contagious only if the patient has syphilitic elements in the oral cavity. It has been suggested that human milk is contagious, even if there are no visible syphilitic changes in the nipple area. The question of the infectiousness of sperm is also interpreted in the absence of manifestations of the disease on the genitals of a patient with active syphilis. At the same time, it is believed that the urine and sweat of patients with syphilis are not contagious. Transmission of infection from a sick mother to the fetus through the placenta is possible. As a result, congenital syphilis may develop.

For the development of syphilis, the amount of the pathogen introduced into the body of the experimental animal is also important. Apparently, this happens in a similar way in humans. For persons who have repeatedly had sexual contact with a patient with an active form of syphilis, the possibility of infection is much greater than for those who have had single and short-term sexual contact. In the blood serum of healthy people there are factors that immobilize Treponema pallidum. Along with other factors, they help explain why infection does not always occur upon contact with a sick person. Domestic syphilidologist M.V. Milich, based on his own data and analysis of the literature, believed that infection may not occur in 49-57% of cases.

Pathogenesis. The main routes of spread of Treponema pallidum in the body are the lymphatic and circulatory systems. Pathohistological studies have shown that in the first days after infection, Treponema pallidum fills the lymphatic gaps and perivascular lymphatic spaces. Only after this they are found in the lumens of small blood vessels and their walls. Explanation

This tropism of Treponema pallidum, which is a facultative anaerobe, is seen in the significantly lower oxygen content in the lymph compared to arterial and venous blood. Treponema pallidums that have entered the body intensively multiply and spread in the lymph, where the oxygen content does not exceed 0.1%, while in venous blood it is 100 times higher, and in arterial blood it is 200 times higher (8-12 and 20%, respectively) .

Along with moving through the lymphatic system, treponemes are carried through the bloodstream to all organs and tissues. This is confirmed by known cases of infection of recipients with the blood of donors in the incubation period of the disease.

During primary and in the first months of secondary syphilis, the spiral form of treponema pallidum predominates, and later it transforms into L-forms and cysts, which serves as a pathogenetic justification for the change from manifest periods of syphilis to latent ones. The phenomenon of seroresistance - the preservation of positive serological reactions after full treatment - is associated with the long-term presence of altered forms of treponema pallidum in the patient's body. Cysts that are not affected by penicillin have antigenic activity, so serological reactions remain positive as long as altered forms of treponema pallidum remain in the body.

The ability of cysts and L-forms to transform back into a virulent spiral form plays an important role in the pathogenesis of clinical and serological relapses of the disease after full treatment. In some patients, after the disappearance of clinical signs of syphilis and negativism of serological reactions, after a few months they suddenly become positive, and in some cases clinical signs of infection reappear. Additional specific (antibiotics) and nonspecific (pyrogenal, vitamins) therapy does not always give the desired results. Only after several months can the titer of serological reactions decrease spontaneously and without additional treatment. Positive serological tests in any case require specific treatment.

The immune system is activated by the interaction of Treponema pallidum with antigen-presenting cells: monocytic cells and Langerhans cells. Having captured the antigen, Langerhans cells enter the mature stage, lose their processes and migrate to the lymph nodes and spleen, where they influence subpopulations

T- and B-lymphocytes enhance the presentation of CD4 antigens, keratinocytes and inflammatory infiltrate cells. In this case, suppression of the cellular component of immunity is observed.

Immunity. Superinfection. Reinfection. With a syphilitic infection, non-sterile (infectious) immunity is formed, which persists until the treponemas disappear. Infection occurs in people with insufficiency of humoral and cellular immunity factors, low levels of treponemostatic and treponemocidal substances in the blood serum. According to the WHO classification, syphilis is a disease with immune deficiency. Cellular immunosuppression was established in the early stages of infection, a decrease in the number of T-lymphocytes in the peripheral blood and T-dependent zones of lymphoid organs.

During the incubation period of syphilis, Treponema pallidum quickly spreads through the lymphogenous route. The body's response in the form of primary syphiloma and regional scleradenitis is delayed. At the end of the primary and beginning of the secondary period of syphilis, a massive proliferation of treponemes occurs and their spread throughout the body (treponemal sepsis). This causes the development of general symptoms of the disease (fever, weakness, malaise, pain in bones and joints, polyadenitis). As a result of the mobilization of immunobiological protective mechanisms, most of the treponemes die and the latent period of secondary syphilis begins.

As the protective processes of the macroorganism weaken, treponemes multiply and cause relapse (secondary recurrent syphilis). After this, the defenses are mobilized again, and in the absence of treatment, treponema pallidum (possibly cyst forms) contribute to the persistence of the syphilitic infection. The undulating course of infection in the secondary period reflects the complex relationship between the micro- and macroorganism.

In the secondary period, factors that suppress the proliferative function of lymphocytes are activated, the phagocytic activity of neutrophils decreases, and their ability to form phagosomes increases. The synthesis of antibodies is activated, the concentration of serum immunoglobulins G, A and M increases. It is believed that at the beginning of syphilis the level of serum IgG and IgM is higher, and in later forms only IgG remains. The antigen-antibody reaction, specific for syphilis, supports the wave-like, staged course of the disease, especially pronounced in the primary and secondary periods.

In the tertiary period of syphilis, when only a small amount of pale treponema remains in the tissues, high sensitization to treponemes and their toxins is manifested by a peculiar anaphylactic reaction with necrosis and subsequent scarring. Since after treatment not only the manifestations of syphilis regress, but also the humoral-cellular factors of immune defense, a new infection is possible with repeated contact.

Repeated infection is called reinfection. To diagnose reinfection, a different location of the chancre than during the first infection, the presence of pale treponema and the appearance of regional scleradenitis are necessary. The reliability of reinfection is confirmed by sufficient treatment of the first infection and negative serological reactions after treatment. The existence of a syphilitic infection through sexual contact is taken into account. Reinfection is distinguished from superinfection - re-infection of an uncured patient. In this case, it is as if a new portion of Treponema pallidum is added to the existing ones, therefore, at different periods of the disease, superinfection manifests itself in different ways. Thus, during the incubation period and in the first 10-14 days of the primary period of syphilis, when infectious immunity has not yet formed, additional infection is manifested by the development of a new chancre. This chancre is smaller in size and occurs after a shortened incubation period (up to 10-15 days). Such chancres are called sequential (ulcera indurata seccentu-aria). In other stages of superinfection, the body responds to a new infection with rashes corresponding to the stage in which it was at the time of the arrival of the new “portion” of treponemes. So, in the secondary period, a papule or pustule appears at the site of infection, in the tertiary period - a tubercle or gumma.

Classification of syphilis

The body's reaction to the introduction and reproduction of Treponema pallidum is manifested by a change in active, clinically pronounced periods of the disease and periods without manifestations on the skin and visible mucous membranes (the so-called hidden, latent periods). The French syphilidologist Ricor drew attention to the natural change of periods during the “classical” course of syphilis. During syphilis, incubation, primary, secondary and tertiary periods are distinguished.

In our country there is a unified classification of syphilis. It is based on the stage of the disease at which the patient first sought medical help.

Below is the division of syphilis according to the International Classification of Diseases, 10th revision. The ICD is based on the etiology, anatomical localization, circumstances of the onset of the disease with a diagnostic description of local manifestations, complications, and main disease processes. To obtain reliable statistical data, their centralized processing, especially with the help of computers, analysis of the epidemiological situation, and adequate assessment of the effectiveness of treatment methods, it seems advisable to use a single terminology.

Since 1999, the ICD has replaced all other classifications of diseases in Russia.