Syphilis and newborns

On our very first day here at the hospital, we were given a guided tour. We noticed that certain diseases such as dengue fever, HIV and syphilis are more common here. In Switzerland, we have mostly encountered these diseases in theory. We noticed that syphilis in particular was mentioned in various wards on the tour - such as the NICU (neonatal intensive care unit) and the maternity ward.

On her very first day in the NICU, Sophie met a baby suffering from syphilis. The mother had undiagnosed syphilis and came to Kantha Bopha Hospital to give birth. She was pregnant with twins and gave birth in the 27th week of pregnancy, which is termed as extremely premature birth. One of the babies died at birth. The other baby had to struggle with the consequences of the premature birth. It lay in an incubator for temperature and humidity control, was ventilated with positive pressure and fed parenterally via an infusion.

Syphilis, an STD (sexually transmitted disease), is mainly transmitted through vaginal, oral or anal intercourse. Here at the Children's Hospital, however, the focus is on vertical transmission - i.e. from mother to child. The disease is caused by the bacterium Treponema Pallidum.

We focus here on syphilis during pregnancy and congenital syphilis. From the 12th week of pregnancy, the fetus can be infected with syphilis via the placenta. Transmission during pregnancy is most likely, in rare cases it can happen during or after birth. The likelihood of transmission depends on the stage of the disease in the mother. In general, the risk of transmission is highest at earlier stages, i.e. when the infection is more recent. According to an expert at the Maternité, transmission in the primary stage at Kantha Bopha Hospital is almost 100 percent; in the literature we find values of 50 to 100 percent.

The consequences of infection of the fetus are serious. It can lead to miscarriage or stillbirth, premature birth and congenital syphilis. The risk of miscarriage or stillbirth is 40 percent. Congenital syphilis is divided into two stages, the early and late stages of the disease. In the early stage, directly after birth, the disease presents with the following symptoms: skin desquamation, jaundice and oedema. After three to ten weeks, further symptoms such as blistering rashes on the palms of the hands and feet, inflammation of the nasal mucosa and bone changes may occur. It is important to note that 70 percent of children do not show any symptoms at this stage and a diagnosis can therefore be missed. This can also lead to the late stage of the disease, which begins from the age of 3. For example, there is the Hutchinson triad: hearing loss, corneal inflammation and barrel teeth.

An important pillar in combating the disease and protecting babies are the four check-ups. The Cambodian government has a program through which mothers are paid for the check-ups. As the examinations at Kantha Bopha Hospital are free of charge, the women can use the money for other purposes, such as travel costs or meals.

The women are tested for syphilis and HIV during the first examination. If the syphilis test is positive, the woman and the father of the child are treated. The treatment is simple and involves three doses of penicillin. To date, no resistance to penicillin has been identified in the bacterium that causes the disease. Treatment can prevent congenital syphilis in 97 percent of cases, which is why syphilis screening is extremely effective.

Not every mother attends every check-up. Some mothers do not attend any check-ups at all and are in hospital for the first time at the birth. In these cases, the child and the mother must be tested and treated if necessary. In other cases, the baby is referred to the hospital after birth and is then also tested.

Dr. Bunthong, the head of the NICU, tells us that before 2022, newborns were only tested for syphilis in suspected cases. Due to the high positivity rate, the systematic testing procedure was introduced as part of the prenatal check-ups. The number of positive syphilis tests was surprising for the hospital and highlighted how prevalent the disease is. From June 2022 to February 2025, 86,969 pregnant women were tested, of which 1817 were positive. For these patients, it can be assumed that the treatment almost always prevented infection of the child. The Neonatology Department had a total of 159 positive cases in 2024 and 28 so far in 2025. These cases are mainly attributable to mothers without screening and referred cases.

Sexually transmitted diseases (STDs) such as syphilis are a problem throughout Cambodia and a sensitive issue. The diseases and their implications for previous sexual partners and fidelity in marriage can have serious consequences for the relationship and the care of the child. Occasionally, there are even cases where a newborn is left in hospital with a positive test. We were told that it is difficult to provide information about STDs and the necessary protective measures during the school years. There are volunteers (from abroad and Cambodian medical students) who visit schools to teach the children and young people about the topic.

The baby with syphilis in the NICU unfortunately died a few days later due to complications from the premature birth. However, the successful screening and the efforts to raise awareness give us hope that such cases will become fewer in the future.

Best regards from Siem Reap

Sophie and Samuel