Introduction

Syphilis, caused by the Treponema pallidum bacterium, is a sexually transmitted infection. Once someone is infected, there are four stages of syphilis they may go through, the primary, secondary, latent, and tertiary stages. Infection with this bacterium is hazardous during pregnancy, causing stillbirths, spontaneous abortion, or transmission from the mother to the newborn. Therefore, syphilis prevention and screening are key in reducing issues during pregnancy.  

Stages of syphilis 

Primary stage

The primary stage is experienced upon contraction of syphilis and lasts for around 21 days. It involves the development of a chancre (hard sore) either around the mouth or in the genital areas. The sore might be healing within a few days, but just because the sore has healed does not mean the infection has been cleared.

Secondary stage

This stage appears around one to six months after the chancre has healed. It may present with a rash and is most commonly found on the palms and soles of the feet. The rash does not itch and may be found on any part of the body. The secondary stage may also present with white or grey lesions and usually may be found on the genitals. Once again, these symptoms will most likely be cleared without treatment but that does not mean the bacteria have been removed.

Latent stage

The latent stage is often symptomless with the possibility of occasional flare-ups. However, the bacteria may still destroy the body, possibly damaging important organs like the heart and brain. This is a very long-lasting stage of syphilis, which could even last twenty years. Transmission at this stage is less likely.

Tertiary stage

The final stage is a manifestation of disease caused by the long-lasting damage by the bacterium to the organs. Considering damage to the heart and brain, conditions such as cardiovascular disease, nerve damage, seizures, or dementia are a possibility. Hence, it is important to get treatment as soon as possible to prevent debilitating organ damage. 

Symptoms 

Syphilis may present with many other symptoms as well as the ones previously mentioned when discussing the stages, such as chancres and rashes. Syphilis may also cause symptoms like:

• Fatigue
• Muscle aches
• Headache
• Fever
• Hair loss
• Weight loss 
• Sores that resemble warts
• Swelling of the lymph nodes 

Diagnosis

Diagnosing syphilis involves an open conversation with a doctor regarding clinical and sexual history with the possibility of a physical examination and assessment. The doctor will likely take a swab of the affected areas, which will be sent to the laboratory for testing. The tests are performed to identify the cause of the disease and the causative agent may need microscopy examination. In severe cases, blood sample tests may be sent for laboratory testing.^1,2

Complications

Apart from the chance of developing diseases aforementioned in the tertiary stage, syphilis infection may spread through the body causing Ocular and Otosyphilis. Ocular syphilis involves the infection of the eye, which may come with blurred vision, light sensitivity, and pain. Otosyphilis involves hearing and balance, causing detrimental effects. Moreover, having syphilis puts you at a two-fold higher risk of contracting other STIs and HIV. Finally, if pregnant, the infection may impact the pregnancy or spread to the child, both of which are potentially dangerous.¹

Syphilis and Pregnancy

Vertical transmission to the fetus

A woman infected with syphilis during pregnancy is likely to pass the infection on to their baby via vertical transmission. The risk of this transmission is dependent on the stage of the syphilis as it is determined by the amount of bacteria in the blood. Congenital syphilis most often occurs when the pregnant mother is either in the primary or secondary stage of syphilis, with the risk dropping if the mother has had syphilis for multiple years and so is in the late latent or tertiary phase. The risk is sometimes low enough that the infection does not get passed on even if the mother has not received any treatment. Either way, congenital syphilis causes major issues for the baby both before and after birth, so early screening and treatment are crucial.

Consequences of Congenital Syphilis

Impact on fetal development

Syphilis may cause problems during fetal development resulting in premature birth as well as a low birth weight. In more serious and unfortunate cases it may lead to spontaneous abortion, stillbirth (when the baby is born dead), or the baby dying shortly after being born. 

Neonatal outcomes

If a baby infected with congenital syphilis survives, it needs to receive treatment in the form of antibiotics as soon as possible. If left untreated the baby may develop either early-stage or late-stage syphilis symptoms. Early-stage symptoms include rashes or lesions on the mouth, anus, or genitals, which may resemble adult syphilis. They may also experience irritability and a fever. Late-stage syphilis symptoms tend to be more severe. These include deformities caused by the destruction of nasal cartilage and bone lesions. The children may also develop tooth abnormalities, blindness, deafness, and neurological issues.

Screening and Diagnosis

Considering the severity of congenital syphilis, early screening during pregnancy is essential to keep the baby safe from severe infection. Hence, speaking to a healthcare professional to receive testing advice is important, especially considering that syphilis infection is not always very obvious as it may present without any or with mild symptoms. The baby itself may also be tested for syphilis via blood tests or spinal tap. 

Diagnostic tests for syphilis

There are two types of tests carried out to diagnose syphilis. First, a non-treponemal test is done, which involves testing for a non-bacterial antibody often found in syphilis patients. As this test is not specific to the syphilis causative bacterium itself, it is followed by a treponema test if positive. This type of test checks for antibodies specific to syphilis, allowing more accurate diagnosis. Microscopy or a polymerase chain reaction may also be used to check for syphilis infection.^3,4

Treatment

Fortunately, syphilis is an easily treated, and curable infection. Pregnant women in the early stages of syphilis tend to receive a benzathine penicillin injection. For later-stage syphilis, more injections will be required. Furthermore, babies suspected to have contracted syphilis from the mother need to be treated using benzathine penicillin as soon as possible, to prevent the development of serious health issues. In some cases, doctors may also use doxycycline, ceftriaxone, or azithromycin for treatment, all of which are antibiotics. 

Prevention Strategies

Primary prevention

It is key to provide people with education about syphilis to know what types of signs to look out for as well as how to practice safe sex to avoid infection in the first place. People should have access to and be informed how to use condoms properly. Furthermore, it is also important to make people aware that syphilis may spread through other means,  which may not be prevented by barrier contraception, such as the mouth, so they should be cautious. 

Secondary prevention

Other than practicing safe sex, it would be useful to have regular syphilis screening for at-risk individuals to identify and treat any less obvious or asymptomatic infection. Patients should also be encouraged to inform their sexual partners so that they also receive treatment to prevent the transmission cycle from continuing as well as also encourage abstinence until treatment is complete. 

Public health initiatives

In less resource-rich countries, awareness, and healthcare access may not be as good as in higher-resource countries. Hence, public initiatives to inform individuals about the topic, andprojects involving the attempt to improve healthcare access, should be encouraged.¹

Summary

Syphilis is a bacterial, sexually transmitted infection, involving four stages of the infection. In some cases syphilis presents with no symptoms or very mild symptoms, making people unaware of the infection hence screening is key. This is especially relevant for pregnant women as there is a possibility of infection transmission to the fetus resulting in issues during fetal development or after birth. Fortunately, treatment is simple, involving a course of antibiotics. Syphilis infection may be prevented by better sexual health education, properly used methods of barrier contraception, and public outreach programs to improve awareness and access to healthcare.