Latent syphilis is a variant of the development of syphilitic infection, in which no clinical manifestations of the disease are detected, but positive laboratory results for syphilis are observed. The diagnosis is complex and is based on anamnesis data, the results of a thorough examination of the patient, positive specific reactions to syphilis (TPI, RPR test), detection of pathological changes in the cerebrospinal fluid. To exclude false positive reactions, repeated studies are practiced, repeated diagnosis after treatment of concomitant somatic pathology and rehabilitation of infectious foci. Treatment is carried out with penicillin preparations.
Modern venereology is facing an increase in cases of latent syphilis around the world. First of all, this may be due to the widespread use of antibiotics. Patients with undiagnosed initial manifestations of syphilis undergo antibiotic therapy independently or as prescribed by a doctor, believing that they are sick with another venereal disease (gonorrhea, trichomoniasis, chlamydia), acute respiratory viral infections, colds, sore throats or stomatitis. As a result of such treatment, syphilis is not cured, but acquires a latent course.
Many authors point out that the relative increase in the incidence may be due to its more frequent detection in connection with the recent mass examination for syphilis in hospitals and women’s consultations. According to statistics, about 90% of this disease is diagnosed during preventive examinations.
Early latent syphilis corresponds to the period from primary syphilis to recurrent secondary syphilis (approximately within 2 years from the time of infection). Although patients have no manifestations of syphilis, epidemiologically they are potentially dangerous to others. This is due to the fact that at any moment early latent syphilis can turn into an active form of the disease with various skin rashes containing a large number of pale treponemas and being the source of infection. The diagnosis of early latent syphilis requires antiepidemic measures aimed at identifying domestic and sexual contacts of the patient, his isolation and treatment until complete rehabilitation of the body.
Disease is diagnosed when the possible infection is more than 2 years old. Patients are not considered dangerous in terms of infection, since when the disease enters the active phase, its manifestations correspond to the clinic of tertiary syphilis with damage to internal organs and the nervous system (neurosyphilis), skin manifestations in the form of low-contagious gum and tubercles (tertiary syphilis).
Unspecified (unknown) latent syphilis includes cases of the disease when the patient does not have any information about the prescription of his infection and the doctor cannot determine the timing of the disease.
In establishing the type of latent syphilis and the prescription of the disease, the venereologist is assisted by carefully collected anamnestic data. They may contain an indication not only of sexual contact suspected of syphilis, but also of isolated erosions in the genital area or on the oral mucosa, skin rashes, taking antibiotics in connection with any disease similar to the manifestations of syphilis that have been noted in the patient in the past. The patient’s age and sexual behavior are also taken into account. When examining a patient with suspected latent syphilis, a scar or residual seal formed after the resolution of the primary syphiloma (solid chancre) is often found. Enlarged and fibrosed lymph nodes after lymphadenitis can be detected.
Confrontation can be of great help in the diagnosis — the identification and examination for syphilis of persons who are in sexual contact with the patient. The detection of an early form of the disease in a sexual partner indicates in favor of early latent syphilis. In the sexual partners of patients with a late form of latent syphilis, no signs of this disease are more often detected, late latent syphilis is less often observed.
The diagnosis must be confirmed by the results of serological reactions. As a rule, such patients have a high titer of reagins. However, in people who have received antibacterial therapy, it may be low. The RPR test should be supplemented with TPI and PCR diagnostics.
Diagnosis is a difficult task for a doctor, since it is impossible to exclude the false-positive nature of reactions to syphilis. Such a reaction may be due to malaria previously suffered, the presence of an infectious focus in the patient (chronic sinusitis, tonsillitis, bronchitis, chronic cystitis or pyelonephritis, etc.), chronic liver damage (alcoholic liver disease, chronic hepatitis or cirrhosis), rheumatism, pulmonary tuberculosis. Therefore, studies on syphilis are carried out several times with a break, they are repeated after the treatment of somatic diseases and the elimination of foci of chronic infection.
Additionally, a study is performed on syphilis of cerebrospinal fluid taken from the patient by lumbar puncture. Pathology in the cerebrospinal fluid indicates latent syphilitic meningitis and is more often observed with late latent syphilis.
Patients with latent syphilis are necessarily consulted by a therapist (gastroenterologist) and a neurologist to identify or exclude intercurrent diseases, syphilitic lesions of somatic organs and the nervous system.
Treatment of latent syphilis
Treatment of early latent syphilis is aimed at preventing its transition to an active form, which is an epidemiological danger to others. The main purpose of the treatment of latent syphilis is the prevention of neurosyphilis and lesions of somatic organs.
Therapy of latent syphilis, as well as other forms of the disease, is carried out mainly by systemic penicillin therapy. At the same time, patients with early latent syphilis may experience a temperature reaction of exacerbation at the beginning of treatment, which is an additional confirmation of a correctly established diagnosis.
The effectiveness of treatment is assessed by reducing titers in the results of serological reactions and normalization of cerebrospinal fluid parameters. During the treatment of early latent syphilis, by the end of 1-2 courses of penicillin therapy, there is usually a negation of serological reactions and rapid sanitation of the cerebrospinal fluid. With late latent syphilis, the negation of serological reactions occurs only towards the end of treatment or does not occur at all, despite the therapy; changes in the cerebrospinal fluid persist for a long time and regress slowly. Therefore, it is preferable to start therapy of the late form of latent syphilis with preparatory treatment with bismuth preparations.