Sexually Transmitted Diseases - I. I. Mavrov 2005

Endemic Treponematoses

Endemic treponematoses (pinta, yaws, bejel) are infectious diseases widely distributed in many countries around the world. They pose a serious public health threat in Latin America, Africa, Southeast Asia, and the Pacific Islands. Recent WHO data raise serious concerns regarding the rising incidence of treponematoses, which are characterized not only by localized outbreaks but also by foci spanning rather vast geographic areas.

Pinta is a chronic tropical infectious disease characterized by the appearance of erythematous-squamous Skin patches prone to hyperpigmentation followed by subsequent depigmentation, accompanied by polyadenitis.

Etiology. The CAUSATIVE AGENT OF pinta is Treponema carateum, which shares morphological and biological properties with the Syphilis spirochete. In experimental settings, it has been inoculated into human volunteers who subsequently developed typical signs of pinta. This disease presents positive biological tests for syphilis. T. carateum cannot be cultivated on artificial nutrient media, but it can infect monkeys.

Routes of transmission. Pinta spreads through direct skin-to-skin contact in the presence of numerous skin abrasions. The penetration of T. carateum into the body is facilitated by the lack of clothing and the presence of skin trauma. Flies of the genus Hippelates are considered potential vectors of the causative agent of pinta (R. Willcox, 1964).

Epidemiology and general pathology. Pinta is an endemic treponematosis prevalent in the jungles of Central America and the northern part of the South American continent (Mexico, Venezuela, Colombia, Peru, Ecuador). The disease is also found in Argentina, Cuba, Haiti, Chile, and the Dominican Republic. Cases of pinta have likewise been reported in Tajikistan.

Human susceptibility to pinta is very high. The epidemiology and Pathogenesis of this disease remain incompletely understood in many aspects. The reservoir or source of infection is an infected individual during the active (contagious) stage of the disease. Instances of simultaneous or sequential infection among multiple family members are well documented. Pinta affects both adults and children, occurring more frequently in rural residents, particularly in humid low-lying areas.

The incubation period averages 2 to 3 weeks. A primary lesion (a non-ulcerated papule) develops at the site of pathogen entry. Several weeks later, a flat hyperpigmented patch forms on the skin, which subsequently undergoes depigmentation and hyperkeratosis. In later stages, the disease may be complicated by cardiovascular and Nervous system disorders.

Clinical manifestations. The course of pinta is divided into three periods. The primary period is characterized by The Development of a papule at the site of treponemal penetration. It is predominantly located on exposed PARTS OF THE body: the face, upper and lower extremities, Nose, neck, and especially the ear region. Over 30–50 days, the papule indurates, transforming into a large, scaling plaque (1.5–2.5 cm in diameter). In some cases, smaller papules appear near this primary lesion, which may coalesce with one another and with the primary plaque. The latter sometimes persists into the secondary stage of the illness, remaining indistinguishable from secondary rash elements.

In the secondary period, skin eruptions appear several months or even years after the primary lesions. The rash first emerges on exposed areas of the skin and subsequently spreads to cover almost the entire Integumentary System. Its elements (pintids) can be of three types: erythematous, erythematous-pigmented, and erythematous-hypochromic (see insert IX, 5). The red coloration of the patches ranges in hue from light pink to violet. Hyperpigmentation may be yellow, brown, or even black. Hypochromia develops either primarily or through the transformation of erythematous and hyperpigmented lesions. Secondary pintids typically scale, and pruritus is observed in A number of cases. Polyadenitis may develop during this period. The secondary stage lasts from 1 to 5 years.

In the tertiary period, depigmented and hyperpigmented patches spread across the entire body, giving the skin a mottled appearance. The affected areas during this stage are predominantly white (resembling vitiligo), as well as pink, copper-red, brownish, and cyanotic. Scaling is absent or minimally pronounced.

The distinctiveness of the aforementioned skin changes is most prominent on the flexor surfaces of the extremities and the face, where depigmented patches are distributed symmetrically. In some cases, xerosis accompanied by diffuse or finely focal hyperkeratosis may develop on the soles and palms. Occasionally, scarring alterations resembling atrophic scars can be found within areas of depigmentation.

Alongside cutaneous manifestations, patients exhibit lymphadenopathy, involvement of Internal Organs (gummatous aortitis, aortic aneurysms), The Nervous System (paralysis), and the osteoarticular apparatus (Arthritis, osteitis).

Diagnosis. Establishing a diagnosis takes into account the medical history, clinical picture of the disease, results of treponemal detection tests, and the Wassermann reaction. Serological tests characteristic of syphilis and other treponematoses are also positive in patients with pinta.

Cytology/practical/136.html">Differential diagnosis OF pinta is carried out to distinguish it from leprosy, vitiligo, syphilis, neurodermatitis, psoriasis, prurigo, pityriasis versicolor, lichen planus, and trichophytosis.

Treatment of pinta involves the administration of benzylpenicillin, erythromycin, and Other Antibiotics. Total cumulative antibiotic doses typically reach 5,000,000 to 10,000,000 IU. The prognosis for this disease is favorable. Preventive measures boil down to detecting and treating infected individuals and their close contacts.

Yaws is a tropical infectious disease belonging to the treponematosis group, characterized by lesions of the skin, mucous membranes, as well as Bones and joints. Internal organs are not affected. Yaws is classified into primary yaws—the stage of the disease marked by a yaws papilloma (framboesioma), lymphangitis, and regional lymphadenitis; secondary yaws—the stage of generalized infection manifested by a massive rash on the torso and extremities; and tertiary yaws—The final stage of the illness, proceeding with The formation of gumbas in the skin, subcutaneous tissue, bones, and joints.

Etiology. The causative agent of yaws is Treponema pertenue, which shares morphological and biological similarities with the syphilis spirochete. It is clearly visible under dark-field Cell/15.html">Microscopy. The pathogen is maintained in laboratory conditions either through animal inoculation, in special solutions, or by freezing infected tissue at -70 °C. In regions where yaws is endemic, T. pertenue has been detected in monkeys, which may serve as a natural reservoir for this infection. Experimental animals (rabbits, hamsters) infected with the agent exhibit clinical manifestations of the infection, whereas other animals (rats, mice) display an asymptomatic course.

Routes of transmission. Yaws is transmitted primarily through direct contact between an infected person and a healthy individual, via household items, bed linens, etc. Sexual transmission is also possible. Flies of the genus Hippelates play a certain role in the spread of the infection (R. Willcox, 1964).

Epidemiology. The disease is widespread in Central Africa, Southeast Asia, Indonesia, Thailand, Laos, and Cambodia. Isolated cases are reported on islands located in the western Pacific Ocean. This infection is endemic (particularly among children) in many countries with hot, humid, and tropical climates.

Infection occurs mainly during childhood. Various minor abrasions of the skin and mucous membranes serve as the portal of entry for the infection. Infected children and adolescents constitute the primary source of its dissemination. They predominantly suffer from the early, most contagious forms of yaws, which poses a particular epidemiological hazard.

The incubation period for yaws ranges from 3 to 6 weeks, though it may extend to several months. During this time, the patient's general well-being either remains unchanged or is marked by prodromal phenomena (malaise, slight fever, loss of appetite, headache, myalgia, arthralgia, etc.).

Immunity in yaws develops more slowly and less robustly than in syphilis. A pronounced cross-immunity exists between yaws and syphilis. A syphilitic infection induces greater resistance to yaws than yaws does to syphilis.

Clinical manifestations. The primary lesion (an ulcerated papule) is typically localized on the skin of the extremities. A hallmark clinical sign of the disease—the framboesioma at the site of pathogen entry—sometimes appears on the mucous membranes as well.

The initial yaws chancre is observed predominantly in children and is usually located on the shins (see insert IX, 4). It may also localize on the face, upper extremities, oral mucosa, and occasionally on the external genitalia.

The primary element of yaws is a solitary, flat, roundish, pink, non-painful, pruritic papule measuring 1–1.5 cm in diameter, surrounded by a narrow yet very vivid pink halo. The papule soon undergoes superficial ulceration. The red Base of the chancre is covered with a "diphtheroid" exudate and a yellow crust, beneath which lie soft, pink, slightly bleeding vegetations. Important initial symptoms of the illness include pruritus and the absence of induration at the base of the framboesioma. The causative agent can be readily detected within the yaws lesion.

The primary stage is characterized by a reaction of the regional Lymph Nodes. They become slightly enlarged and may be painless, especially in cases of secondary infection of the frambesioma. In addition to lymphadenitis, a regional lymphangitis may develop, presenting as a pinkish cord along the lymphatic vessel that is slightly tender upon Palpation. The patient's general condition usually remains typical of the course of yaws.

The initial yaws lesion lasts from 2–3 weeks to several months. In some cases, it changes little over time and may even persist alongside later clinical manifestations of the disease. However, sooner or later, the frambesioma gradually resolves, leaving a temporary or permanent whitish atrophic scar. Scars frequently form at the sites of skin lesions.

Typically, 3–6 months after the appearance of the primary lesion, an early (secondary) generalized rash develops, which relapses 2–3 times During the first 3–5 years. The onset of the secondary stage indicates further generalization of the infection. Like the primary stage, it may be preceded by mild constitutional symptoms.

Clinically, the secondary stage is defined by the appearance of an itchy rash on the trunk and, less commonly, on the extremities—consisting of maculosquamous and papular eruptions, vesiculopustules, papulotubercles, and even ulcers. Most frequently, however, one observes slightly edematous, pink macules the size of a little-finger nail, which rapidly transform into papules with slight central depression.

The morphological elements of the rash are distributed diffusely or show a tendency to group. The eruptions are accompanied by quite intense itching. After 2–3 weeks, some of these elements spontaneously resolve, leaving initially pigmented and subsequently depigmented (with a whitish hue) subatrophy.

A roseolous rash is recorded infrequently; it appears 20–30 days after the primary element. The yaws roseola is small, round, may be scaly, and is poorly visible on the dark skin of indigenous populations, As a result of which patients do not always notice it and rarely seek medical attention.

Simultaneously with the roseola, or in the interval between the appearance of the macular and papillomatous rashes, there may be observed depigmented, branny, scaly patches, dense lichenoid papular elements covered with grayish scales, and larger lenticular papules that in some cases are arranged annularly, resembling a cockade in shape.

Another variety of secondary eruptions is represented by lupoid lesions resembling lentil-sized tubercles of soft-elastic consistency, located predominantly on the face. They frequently ulcerate, become covered with massive crusts, and heal with scar formation. Scars at the site of skin lesions are typical of yaws. In some cases, these scars can be disfiguring, leading to lymphedema—especially on the feet—as well as elephantiasis, joint contractures, and bone deformations.

Hyperkeratosis develops on the soles and palms, presenting as localized or diffuse forms accompanied by deep fissures and ulcers, pain upon walking, and, consequently, a characteristic gait: patients bear weight on the outer edges of their feet, resembling a waddling motion.

The scalp, oral mucosa, nasal mucosa, and conjunctiva are rarely affected initially. Such localization of early eruptions is noted only in hyperendemic areas. The mucous membrane may become involved in the pathological process when rashes spread to it from the skin of the Lips, alae nasi, and eyelids.

During the secondary stage of yaws, the Nails may also be involved in the pathological process, manifesting as destructive changes: they darken, thicken, can become deformed, and may even be shed.

In the tertiary (late) stage, lesions typically appear 3–5 years after the onset of early symptoms or immediately following them, manifesting as gummas, palmoplantar hyperkeratosis, bone changes, juxta-articular nodules, and dyschromia. Gummas and gummatous infiltrates are frequently found on the lower extremities. Gummas are clearly demarcated, rise above the skin level, and have a firm-elastic consistency; the skin over them is pinkish-red, and subjective sensations are absent.

Gummas and gummatous infiltrates are prone to ulceration. The ulcers are painless, often pruritic, with firm, elevated edges; their base is covered with a grayish-bloody discharge and, in places, by crusts, above which pinkish granulations are revealed. They usually heal with the formation of a stellate scar.

Late yaws lesions in adults may manifest as juxta-articular nodules. These are subcutaneous fibrous nodules ranging in size from a walnut to a chicken egg, developing predominantly in the region of the extensor surfaces of the elbow and knee joints. They may be located symmetrically in the knee region and over the greater trochanter of the Femur, and in rare cases are found on the dorsum of the hands. Sometimes, hyperkeratosis develops in the skin overlying the nodules.

Juxta-articular nodules persist for a long time without impairing joint function. A very characteristic feature is their mobility relative to the overlying skin—which, as a rule, remains unchanged—and the underlying Tissues. Usually, these nodules are multiple (4–5 or more) and symmetrical; they can persist for decades, although they occasionally resolve spontaneously, and their ulceration is extremely rare.

In late yaws, periostitis, osteitis, and epiphysitis frequently occur. The long bones are more commonly affected—the Tibia, femur, humerus, radius, and clavicle. Diffuse and nodular osteoperiostitis resemble the lesions seen in tertiary syphilis.

The results of the Wasserman reaction, TPI (Treponema Pallidum Immobilization), and immunofluorescence tests in patients with active forms of yaws are generally positive. The CEREBROSPINAL FLUID is usually unchanged. Complications involving the internal organs and nervous system are rare.

Late manifestations of yaws include distinctive lesions of the bones and soft Tissues of the face, known as goundou and gangosa.

Goundou is characterized by the development of exostoses of the nasal processes of the Maxilla on both sides of the ROOT of the nose (more rarely on one side); these develop at the end of the early stage and more rarely in the late Stages of the disease. It causes considerable suffering to patients.

Gangosa is a disfiguring rhinopharyngitis; a severe manifestation of the late stages of yaws. As the pathological process progresses, significant destruction of the soft and bony tissues of the face occurs, as well as of the soft and hard palate, jaws, eyelids, and even the eyeballs. Only the Tongue is spared from the process. Destruction of the frontal bones and the consequent development of Brain hernias have been described.

Diagnosis. Diagnosis is relatively straightforward and is based on anamnestic data, consideration of all the aforementioned clinical symptoms, and the results of Laboratory tests (detection of the causative agent, serological reactions—Wasserman, TPI, immunofluorescence). Differential diagnosis is conducted with late manifestations of syphilis, cutaneous leishmaniasis, skin tuberculosis, localized forms of sporotrichosis and blastomycosis, and impetigo.

Treatment. Patients with yaws are prescribed penicillin group drugs, including long-acting formulations, and less frequently, other antibiotics. In continuous treatment, the daily dose of benzylpenicillin should be at least 1,000,000 IU, and the duration of treatment at least 15 days. Good effects can be achieved using tetracycline and erythromycin (daily dose 1.5–2.0 g; course dose 20–30 g).

Prophylaxis. The control of yaws, much like other endemic treponematoses, can be successful only through the long-term and planned Structure/175.html">Implementation of preventive measures and the improvement of the economic, social, and living conditions of the population. Of major importance are the raising of sanitary culture, mass population screenings, and the detection and mandatory treatment of all patients. The yaws control campaign conducted by the WHO has produced significant effects. However, neither epidemiological nor total eradication of this infection has yet been achieved in any territory.

Bejel (endemic syphilis) is a chronic infectious disease manifested in the early period by erythematopapular skin rashes, and in the late period by gummas, most commonly affecting the bones. It is observed predominantly in children.

Etiology. Bejel is caused by a spirochete similar to the syphilis agent, Treponema bejel. In its morphological and biological properties, this microorganism is closely related to T. pallidum, the causative agent of venereal syphilis. Minor antigenic and pathogenic differences between these agents reflect only strain CHARACTERISTICS OF THE same microorganism. Bejel contracted in childhood subsequently "protects" against infection with venereal syphilis.

Modes of transmission. The disease is transmitted primarily through everyday contact involving the skin, particularly among children. It is widespread in humid tropical regions where the population wears minimal clothing—a factor that would otherwise significantly reduce the risk of infection. Transmission occurs more frequently via contact with mucous membranes, contaminated hands, and household items (such as utensils). Sexual transmission of the infection cannot be ruled out.

Epidemiology. Bejel is predominantly found in Africa, the Middle East, and Southeast Asia. To this day, cases of the disease continue to be reported among Bedouin populations in Kuwait, and with particular frequency in Syria, Yemen, Jordan, Iraq, Lebanon, Egypt, Israel, Iran, and Turkey.

Infection most commonly occurs between the ages of 2 and 10. The incubation period of bejel has not been definitively established, though most authors estimate it to average several weeks. The disease exhibits pronounced endemicity, with outbreaks potentially affecting 40–60% of the population in a given region. Among Bedouin communities, bejel is frequently diagnosed in more than half the members of large extended households.

Clinical manifestations. Primary signs of bejel are extremely rare. Consequently, the disease often presents with generalized or localized rashes on the skin and mucous membranes, resembling the secondary-stage eruptions of syphilis. These lesions predominantly appear as papules and macules.

The rash most frequently localizes to the oral mucosa, Pharynx, trunk, and face, and less commonly on the extremities. Eruptions occurring at mucocutaneous junctions are highly characteristic, particularly at the corners of the Mouth, around the anus, and on the genitalia. In areas subject to friction and increased moisture, papules may hypertrophy and develop into broad condylomas, which can also present as isolated lesions.

A distinct sequence of eruptions is typically observed: they first appear in the Oral Cavity, followed by weeping papules in skin folds, and subsequently by a papular rash on the trunk and limbs. The rash persists for 1–2 years. By the 3rd to 5th year, lesions of the skin and mucous membranes develop, closely resembling the gummatous manifestations of venereal syphilis. Bone involvement (osteoperiostitis, Osteomyelitis) likewise mimics syphilitic pathology. Plantar hyperkeratosis and skin achromia are characteristic of the late stage of bejel.

Internal organs and the nervous system are virtually unaffected, and the General condition of patients usually remains undisturbed. Mild malaise, weakness, moderate fever, and—in children—gastrointestinal disturbances may occasionally occur. Lymphadenitis is observed very rarely. The disease is not transmitted hereditarily.

Diagnosis of bejel is based on the Clinical presentation, epidemiological data, and laboratory findings. The causative agent is readily detected in early lesions. Serological tests (Wassermann reaction, TPI, IFA) yield positive results in the majority of cases, although the reagin titer tends to be slightly lower than that observed in syphilis.

Treatment and Prevention. Long-acting penicillin preparations are used successfully to treat bejel, administered in dosages identical to those employed for syphilis. The prognosis is favorable due to the high efficacy of penicillin-Class antibiotics. Preventive treatment is recommended for household contacts of patients, as well as for individuals in close association with them.