Congenital syphilis includes early congenital syphilis, late congenital syphilis, and congenital latent syphilis. If syphilis in pregnancy is adequately treated before 16 weeks of gestation, congenital syphilis in the next generation can be almost completely prevented. Risk factors associated with the development of congenital syphilis include: pregnant women with sexually transmitted diseases, poverty, and drug use; inadequate prenatal care or prenatal care but no syphilis serologic screening; asymptomatic or high syphilis serum titers; some recent syphilis infections that have not yet developed serum antibodies at the time of screening and those with unknown disease.
Early congenital syphilis develops before birth to 2 years after birth, usually within the first 3 months of life and mostly within 5 weeks of birth. Some fetuses with severe intrauterine infection may be stillborn. Despite treatment with antibiotics, some children die in the early neonatal period. Some infected newborns may have no clinical manifestations and are not diagnosed until they show clinical signs of multi-organ involvement. Late onset congenital syphilis is a late manifestation of congenital syphilis that often develops between 5 and 8 years of age, with multiple symptoms appearing at 13 to 14 years of age, and late onset symptoms appearing at 20 years of age or later. Children with congenital latent syphilis have no clinical symptoms, but have a positive serologic test for syphilis.
Infants born to mothers with syphilis in pregnancy should be tested and evaluated for syphilis if the mother has
1. has untreated syphilis
2. if syphilis treatment was started less than one month before delivery
3, who have been treated with non-penicillin therapy during pregnancy
4, after anti-syphilis treatment, non-syphilis spirochete antibody titers have not been reduced as expected
5, lack of evidence of adequate anti-syphilis treatment
6, has been treated, but the efficacy of treatment has not been determined.
The following clinical and laboratory tests and evaluations should be performed for infants born to pregnant women who meet the above criteria.
1. a complete physical examination for signs of congenital syphilis
2. non-syphilis spirochete antibody titer test.
3. cerebrospinal fluid examination
4. long bone x-ray.
5, other tests required for clinical purposes.
6.Syphilis spirochete antigen test.
The main diagnostic basis for congenital syphilis includes.
1, mother’s history of syphilis.
2, typical clinical symptoms and signs.
3, finding syphilis spirochetes from the lesion site, placenta or umbilical cord.
4, positive syphilis serology test.
The main problems in the laboratory diagnosis of congenital syphilis are.
1, diagnosis of congenital latent syphilis in the neonatal period, i.e., asymptomatic occult infection, is more difficult, with congenital latent syphilis accounting for more than 50% in high-risk infants.
2. The establishment of follow-up and comprehensive assessment system for infants at high risk of congenital syphilis, with syphilis serologic diagnosis as the core link: long follow-up period, at least 6 months (3 times) and up to 18 months; poor acceptability of cerebrospinal fluid and other tests; often insignificant antibody changes in syphilis serologic follow-up, leading to patient misunderstanding; poor compliance due to social and family reasons.
3, there is no laboratory diagnostic tool with ideal diagnostic efficacy.
4. The progress of pathogenic diagnosis is slow and has not yet been applied in clinical practice.
Traditional serological tests are mainly divided into the following categories according to the serum markers detected
(1) Non-TP-specific serological tests: detect cardiolipin or lipid-like antibodies in serum, mainly including: USR, VDRL, TRUST and RPR, etc. It is often used for quantitative (titer) analysis, mother-infant titer comparison, follow-up and efficacy determination.
(2) TP-specific serological tests: The detection of anti-TP-specific antibodies in serum includes the syphilis spirochetal brake test (TPI), the microhemagglutination test for syphilis spirochetal antibodies (MHA-TP), the syphilis spirochetal hemagglutination test (TPHA), the syphilis spirochetal passive gelatin particle agglutination test (TPPA), and the fluorescent dense spirochetal antibody absorption test (FTA-ABS).
The significance of traditional serological tests in the diagnosis of congenital syphilis are.
(1) Non-TP-specific serological test for newborns: NCLS can be diagnosed when its titer is greater than or equal to 4 times or more than the mother’s titer; for those who are not infected or treated in the neonatal period, the titer should decrease after 3 months and turn negative within 6 months.
(2) TP-specific serological test: If the test remains positive until 15-18 months after birth, the diagnosis of CS can be made, and it is only used as a retrospective diagnosis in the diagnosis of NCLS.
Disadvantages are.
1, poor specificity: because it cannot distinguish between syphilis spirochete IgG (TP-IgG) and IgM (TP-IgM) antibodies, and maternal TP-IgG can enter the fetal circulation through the placenta, so when the serum of asymptomatic newborns is positive for RPR, TPPA, etc., it cannot be diagnosed as NCLS; in addition, a theoretically negative test cannot exclude the diagnosis of NCLS.
Poor sensitivity: NCLS can be diagnosed when the titer of non-TP-specific serological test in newborns is greater than or equal to 4 times the mother’s titer, but only 22% of non-TP-specific serological test titers in children with confirmed CS are greater than or equal to 4 times the mother’s titer, and the rate is presumed to be even lower in NCLS. Only a very small number of children with congenital syphilis become symptomatic in the neonatal period, and some children with untreated or poorly treated congenital syphilis become symptomatic later in life, while others remain asymptomatic. The diagnosis of congenital syphilis lacks a gold standard and often requires a comprehensive analysis based on clinical, x-ray and serological analysis.
Treatment principles for congenital syphilis: penicillin or procaine penicillin is preferred for congenital syphilis, and if treatment is interrupted for more than one day, the entire course of treatment must be started from the beginning. Infants should be treated if they have
1. any manifestation of active syphilis physical examination or x-ray
2. a positive cerebrospinal fluid VDRL or rapid plasma reactin ring card test (RPR).
3. abnormal cerebrospinal fluid examination (e.g., white blood cell count >5 cells/mm, or protein >500 g/L) regardless of VDRL or RPR test results.
4. non-syphilis spirochete serum antibody titers that are more than four times higher than those of the mother.
5. Positive syphilis spirochete antigen. 6 Even if the test is normal, if the mother’s syphilis is untreated, or if there is a basis for recurrence or reinfection after treatment.