Syphilis is a sexually transmitted bacterial infection (STIs) due to infection with Treponema pallidum. It is characterized by four stages: primary, secondary, latent and tertiary.

1.      Primary syphilis is manifested by the emergence of a papule which over time becomes depressed leading  to the development of a ulceration – tough chancre. Chancre occurs at approximately three weeks (7-90 days) from sexual contact and heals, on average, after three to six weeks. Tough chancre has variable localizations according to sexual behavior (most commonly in the anogenital area). If it appears in the cervix, the infection may go unnoticed in the initial stages. Untreated persons develop secondary syphilis.

2.      Secondary syphilis can occur 4-10 weeks after primary infection. It manifests itself through maculopapular lesions, localized anywhere on the body. Pale papules may be observed at the level of mucous membranes (condiloma lata).

Attention! There have been recorded situations in which patients with secondary syphilis have not shown signs of prior primary syphilis. Both primary and secondary lesions are highly contagious.

3.      It is estimated that one third of cases are healed, a third stays in latent syphilis stage (detectable by serological laboratory techniques), and the rest evolve towards tertiary syphilis.

4.      Tertiary syphilis may occur after 2-15 years after primary infection. It has a relatively frequent cardiovascular, neurological (granulomatous lesions) manifestation.

Congenital syphilis is the result of mother-to-child transmission. A pregnant woman infected with Treponema pallidum, can transmit bacterium:

• to fetus through the placenta between the 10-15 weeks of gestation. The bacterium can be transmitted transplacental at all stages of the infection with syphilis.
• at any time of pregnancy and at any stage of the infection, being more common in primary syphilis and in secondary syphilis and resulting in various effects on the fetus.

Effects of infection on the Fetus:

·         Fetal Hydrops,

·         Intrauterine growth restriction,

·         Premature birth,

·         Fetus born dead,

·         Spontaneous abortion in up to 50% of pregnancies.

Children with congenital syphilis may be born:

-with obvious signs of syphilis (early congenital syphilis)

–apparently healthy (tardy congenital syphilis)

Manifestations of early congenital syphilis:

-Skin Lesions

-Syphilitic Coryza

-Necrotizing Funiculitis

-Generalised Adenopathy

-Hepatosplenomegaly

-Osteochondritis and Perichondritis

-Renal impairment

Manifestations of tardy congenital syphilis:

-Sensory deafness

-Interstitial keratitis

-Hutchinson Teeth

-Nose in saddle

-Periostitis

-Cheek bone hypoplasia

-Anomalies of the central nervous system

Tests for the screening of syphilis in the pregnant woman shall be performed on the first antenatal visit and shall be repeated at the beginning of the third trimester of pregnancy.

• Initial diagnostic tests are nontreponemic tests, which detect antibodies, for example:

-VDRL (Veneral Disease Research Laboratory),

-RPR (Rapid plasma reding).

• Nontreponemic tests must be confirmed with tests using treponemic antigens to exclude false positive results, these are called Treponemic tests, which detect specific-species antibodies, for example:

-TPHA passive haemagglutination test (Treponema Pallidum Haemagglutination assay),

– FTA-Abs indirect immunofluorescence test (Fluorescent Treponemal antibody Test).

• If the pregnant infection is old, healed before pregnancy, the nontreponemic tests are negative, and the treponemic ones are positive.

The pregnant woman has the possibility of a false positive reaction related to pregnancy. In these situations, determination by the  (EIA)-IgM imunoenzimatic test of antitreponemic IgM antibodies allows the differentiation of an old syphilis with residual antibodies of a new, progressive syphilis. The first antibodies that occur are specific antitreponemic IgM antibodies, which can be detected at the end of the second week of infection; antitreponemic IgG antibodies appear later in the fourth week. Thus, at the onset of clinical symptoms, the majority of patients present IgM and IgG antibodies.

Diagnosis of Newborn

All newborns with seropositive mothers are tested within the first month of birth, in parallel with the mother, by quantitatively VDRL from the serum. If the antibodies titer detected in the newborn is four times greater than the mother antibodies titer is considered congenital syphilis. The diagnosis can be confirmed by direct viewing of Treponema pallidum in microscopy with dark background from lesions (more frequently in nasal secretions). In cases of confirmed serology at birth, is also mandatory mother and child testing for HIV infection.

For neonatal screening, serum is preferred to umbilical cord blood, which leads to more false-positive reactions.

In early phases of the infection the serological tests may be unreactive.

At birth of a newborn from a HIV positive mother, the baby has the same serological profile as the mother from which the passive transfer of IgG type antitreponemic antibodies has been made and, in the case of an uninfected child, which will disappear within the first 3-6 months.

The serological control of the uninfected child is made in order to monitor the progressive decrease of antibody titers through quantitative tests.

In the infected and treated child, antitreponemic antibodies persist for a long time and only the significant decrease of VDRL allows the treatment efficacy follow up. The dosage of IgM type antitreponemic antibodies in the newborn, differentiates between the passive passage of antibodies from the mother (IgG type) and the active synthesis of antitreponemic antibodies of IgM type by the newborn. A serological profile with antitreponemic antibodies of IgM negative type does not preclude the diagnosis of congenital syphilis if the mother was tardy infected during pregnancy.

Nota Bene. In this document, the laboratory diagnosis in infection with Treponema pallidum s.s. pallidum has not been detailed, but only few elements related to pregnancy and newborn were pointed. For complete diagnosis of this infection, those interested will address to the Dermatovenerologist colleagues.

The infectious agent

Syphilis is due to infection with a more peculiar bacterium. It is Treponema pallidum, a spirocheta belonging to Spirochaetaceae family, the Spirochaetales order. There are three subspecies, that morphologically, can not be differentiated: Treponema pallidum S.S. Pallidum, Treponema pallidum S.S. Endemicum (endemicsyphilis or Bejel) and Treponema pallidum S.S. Pertenue (piano).