The Microbiological Disease Syphilis in Pregnancy-Clasification

Introduction
For several decades, syphilis has been out of sight, mind, and memory, but the incidence in the Western world is now on the rise again and it could once more become a major health concern. This change has followed the rapidly rising number of human immunodeficiency virus (HIV) positive individuals worldwide, together with the advent of health tourists, economic migrants, asylum seekers, and the easy availability of low-cost travel.
Just as syphilis has all but disappeared as an entity in the working memory of most anaesthetists, it has suddenly re-emerged as a co-existing condition in women presenting for Caesarean section.
Incidence of Syphilis
The 1999 WHO estimates suggest an annual rate for syphilis of ~12 million active infections. The risk of contracting syphilis through a sexual contact with a person with primary or secondary syphilis is 30–50%. More than 80% of women with syphilis are in reproductive age; therefore, there is a serious risk of vertical transmission to the fetus.[6] Worldwide, a million pregnancies are adversely affected each year by syphilis because of maternal infection. About 270 000 babies are born with congenital syphilis, 460 000 pregnancies end in abortion or perinatal death, and 270 000 babies are born prematurely or with low birth weight.[7]

Aetiology[1]
Treponema pallidum is the causative organism for syphilis. It is a delicate, motile spirochete bacterium. Humans are its only natural source. Syphilis is usually transmitted by sexual contact through exposure to mucocutaneous syphilitic lesions that contain infectious spirochetes. The infecting organism in body fluid gains access through microscopic abrasions in skin or mucosal surfaces, and begins to replicate locally. After inoculation, the incubation period is around 3 weeks (10–90 days), at the end of which a primary sore develops at the site of infection, usually the genitalia.

Classification
Syphilis is classified[2] as congenital or acquired. There are four stages of syphilis: primary, secondary, latent, and late (tertiary).

Primary Syphilis
The first development is a chancre at the site of inoculation, classically in the anogenital region which is a painless, solitary, round indurated ulcer with a bright red margin.[1] Chancres appear on average about 3 weeks after sexual contact and heal in 3–6 weeks. However, with a small inoculum, this incubation period may be as long as 90 days. One of the common sites for lesions is the cervix; therefore, the clinical manifestations of primary syphilis may go unnoticed by the patient and her partner.[3]
Secondary Syphilis
Untreated patients will progress to secondary syphilis after the signs for primary syphilis resolve (within 4–10 weeks[3]). The lesions are numerous, variable, and affect many systems. A symmetrically distributed, maculopapular, non-irritating rash is found on the palms and the soles with painless lymphadenopathy. The highly infectious condyloma lata are found on warm and moist areas such as genitalia, perianal region, perineum, and axillae. Both meningism and headache can occur, especially at night. Their cause can be confirmed by the presence of an elevated cell count and elevated proteins in cerebrospinal fluid. Less common accompaniments to secondary syphilis include alopecia, laryngitis, mild hepatitis, nephrotic syndrome, bone pain, and uveitis.
Latent Syphilis
The natural history of untreated secondary syphilis is marked by spontaneous resolution after a period of 3–12 weeks, leaving the patient entirely free of symptoms. This naturally attained asymptomatic state is called latency.[4] The latency is arbitrarily subdivided into early (<2 yr from the onset of the infection) and late (>2 yr) stages. During this time, the patient remains serologically positive for syphilis. Approximately 60% of patients remain latent for the rest of their lives. In the early latent stage, 25% will relapse with a secondary syphilitic manifestation, whereas the likelihood of such relapses in the late latent stage is small.[1]
Late Syphilis (Tertiary Syphilis)
Tertiary syphilis develops in 30–40% of untreated patients. The three main manifestations of late syphilis are cardiovascular, gummatous, and neurosyphilis. Cardiovascular syphilis usually occurs 15–30 yr after primary syphilis and may occur in any large vessel. It is characterized, by an aortitis, aortic incompetence, coronary ostial stenosis (presenting as angina), and aortic medial necrosis causing aortic aneurysm. Gummatous syphilis is granulomatous locally destructive lesions that usually occur 3–12 yr after inoculation. They can occur in almost any tissue. Neurosyphilis presents with a variety of syndromes including general paresis, tabes dorsalis, syphilitic meningitis, and meningovascular syphilis. The incubation period is 5–12 yr.[5]
Syphilis in Pregnancy
Antenatal syphilis poses a significant threat to the pregnancy and fetus. T. pallidum readily crosses the placenta, resulting in fetal infection. Vertical transmission can occur at any time during pregnancy and at any stage of syphilis.[6] Risk of transmission correlates with the extent of spirochetal presence in the circulation. Vertical transmission of syphilis is more common in primary (50%) and secondary syphilis (50%), compared with early latent (40%), late latent (10%), and tertiary syphilis (10%). Seventy to one hundred per cent of infants born to untreated infected mothers are infected. Pregnancies complicated by syphilis may result in intrauterine growth restriction, non-immune hydrops fetalis, stillbirth, preterm delivery, and spontaneous abortion in up to 50% of pregnancies. Women who had documented treatment for syphilis in the past do not need treatment during current or subsequent pregnancies.
Congenital Syphilis
In spite of a downward trend in the incidence of syphilis, congenital syphilis, an infection passed from mother to child through the placenta during fetal development or birth, remains a great concern. An infected woman’s potential to infect her fetus remains for many years, although the risk of infecting a fetus declines gradually during the course of untreated illness. After 8 yr, there is little risk, even in the untreated mother. Nearly half of all children infected with syphilis during gestation die shortly before or after birth.
Infants who survive develop early-stage and late-stage symptoms of syphilis, if not treated. Early-stage symptoms include irritability, failure to thrive, non-specific fever, a rash and condyloma lata on the borders of the mouth, anus, and genitalia. Some of these lesions may resemble the wart-like lesions of adult syphilis. A small percentage of infants have a watery nasal discharge (sniffles) and a saddle nose deformity resulting from destruction of the cartilage of the nose. Bone lesions are common, especially in the upper arm (humerus). Later signs appear as tooth abnormalities (Hutchinson teeth), bone changes (sabre shins), neurological involvement, blindness, and deafness.