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  • Cases of congenital syphilis have tripled in recent years.
  • The disease occurs when a mother who has syphilis passes the bacteria to their baby during pregnancy. 
  • Congenital syphilis is caused by a bacteria, called Treponema pallium, that can be transmitted from a pregnant person to their baby, even if the parent has received treatment. 

Cases of congenital syphilis have increased significantly over the past few years. 

In 2020, 2,000 cases were reported — the highest number of cases reported in a year since 1994.

Mississippi recently reported a 900% increase in cases, according to hospital billing data shared with NBC News.

Many other states, including California, Minnesota, and New Mexico, have reported alarming increases as well. 

The disease occurs when a mother who is infected with syphilis passes the bacteria to their baby during pregnancy. 

And though many mothers and babies many be asymptomatic, some will develop serious health issues, like deformed bones, severe anemia, and brain and nerve problems.

“Cases have been increasing for some years in the US and represent a failure to identify and treat syphilis cases in pregnant women — something that is done in routine prenatal care. The cases also reflect general increases in syphilis more generally as well,” Dr. Amesh Adalja, FIDSA, a senior scholar at the Johns Hopkins University Center for Health Security and an infectious disease expert, told Healthline.

What is congenital syphilis?

Congenital syphilis is caused by a bacteria, called Treponema pallium, that can be transmitted from a pregnant person to their baby, even if the parent has received treatment. 

“The rising congenital syphilis numbers [in the USA] reflect the reality of the nation’s syphilis epidemic and the growing trend of syphilis infections among women and their male sex partners,” Dr. Robert McDonald, of the Division of STD Prevention, CDC, told The Lancet Microbe in 2021. McDonald pointed out that from 2015 to 2019 the “rates of primary and secondary syphilis increased more than 170% in reproductive-age women”.

What is syphilis?

A person may contract syphilis during sexual contact if they have direct contact with a sore related to the disease.

Signs of syphilis include sores, rashes, fever, weight loss, muscle aches, and fatigue among others.

Without treatment, syphilis can reach the latent stage where no symptoms are visible, but the disease is still present.

In rare cases, people can develop tertiary syphilis where the disease affects the heart, blood vessels, and brain. This stage can happen 10 to 30 years after the disease was first contracted. The damage to internal organs can be fatal.

If syphilis is untreated it can cause major issues to other organs such as the brain, eye, and nervous system.

The disease can be effectively treated with antibiotics.

Here’s what’s behind the uptick

Infectious disease specialists believe the COVID-19 pandemic has fueled the incidence of congenital syphilis.

Many people delayed routine healthcare services like STD screenings. 

“The quickest way for people to spread STIs is to not know that they have one, Casey Pinto, PhD, MPH, NP-C, an assistant professor of public health sciences at Penn State College of Medicine in Hershey said in a press release. “The inability to detect asymptomatic cases could have negative repercussions for years to come.”

Pinto was part of a team that published a study in 2021 that found STI screenings for men decreased 63% and 59% for women in the early months of the pandemic.

“Reduced focus on other infectious diseases has led to a rise cases,” Dr. Dawn Sokol, a pediatric infectious diseases specialist with Ochsner Hospital for Children, said.

Research also suggests that decreased funding in sexual health services has contributed to the rise in cases.

A study conducted in Chicago that evaluated more than 100 cases of congenital syphilis between 2014 and 2018 found that delayed or limited healthcare access exacerbated the incidence of congenital syphilis.

According to those findings, the majority of women with syphilis experienced social determinants of health (SDOH) that prevented them from easily accessing healthcare, such as experiencing homelessness or lacking health insurance. 

A study from Indiana similarly found that SDOH like substance use and incarceration contributed to congenital syphilis cases.

Sexually transmitted infections — including syphilis but also chlamydia and gonorrhea — have increased significantly over the past decade.

Between 2015 and 2019, there was a nearly 30% increase in syphilis, chlamydia, and gonorrhea cases.

Congenital syphilis is easily detected and treated, but without public health services, the infection can go undetected and untreated. 

Effects of congenital syphilis on infants and pregnancy

Pregnant people who have syphilis are at risk for significant complications including miscarriage, stillbirth, premature delivery, low birthweight, or increased risk of infant death soon after birth, according to the Centers for Disease Control and Prevention (CDC).

Infants who are born with congenital syphilis can face a range of health issues, according to the CDC.

This includes anemia, meningitis, jaundice, deformed bones, severe anemia, enlarged liver and spleen.

How to stop the spread

“The timing and follow-up of mother’s infection are important in determining the risk to the newborn,” Sokol said.

All mothers are screened for syphilis during pregnancy. If they test positive, their baby is then tested as well.

Many babies who contract the infection are asymptomatic. Some may develop a rash or congestion. 

“When other symptoms are found they can include an enlarged liver or spleen, enlarged lymph nodes, runny nose, and jaundice,” says Sokol.

The California Department of Public Health recommends pregnant people be screened twice during pregnancy and once during delivery to ensure they do not have syphilis.

Babies who are diagnosed with congenital syphilis will need to undergo lab studies to see how the disease has affected their health. 

Treatment options include a single injection of penicillin or a 10 course of IV therapy, according to Sokol.

In some cases, the damage may be permanent, says Adalja.

The only way to prevent congenital syphilis is to practice safe sex practices and undergo routine screening, Adalja said. 

The bottom line:

Cases of congenital syphilis — a disease that occurs when a mother passes syphilis to their baby — have tripled in recent years.

Health experts believe a lack of public health measures contributed to the increased incidence of congenital syphilis. Reduced funding for sexual health services, combined with the delayed health services during the COVID-19 pandemic, fueled the spread of sexually transmitted infections. 

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