Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum.

During pregnancy, this bacteria can pass from a mother with untreated syphilis, known as maternal syphilis, to her child in utero, causing the fetus to contract congenital syphilis.

In January 2026, the U.S. Centers for Disease Control and Prevention reported that the rate of maternal syphilis rose by 28% from 2022 to 2024, from just over 280 to nearly 360 cases per 100,000 births.

I’m a public health researcher and infectious disease nurse practitioner. I study disparities in sexually transmitted infections, or STIs, and I’m currently conducting a study on syphilis in pregnancy.

A perfect storm of factors behind the rise

Two factors in particular have to be taken into consideration to understand the steep rise in cases.

One is the rise in syphilis cases in the general population – which naturally leads to an increase in maternal syphilis – and the other is the specific variables such as funding and access to care barriers that affect pregnant women when it comes to the spread of this disease.

The overall trend of increasing syphilis rates is the result of what I would describe as a perfect storm of factors, from lack of funding to COVID-19. The rate of syphilis infections in the U.S. has been steadily increasing since 2000.

In 2018, there was a sharp increase in this rate, as the group predominantly affected by this STI shifted from men who have sex with men to the general population of both men and women.

This shift caused an increase in rates of maternal syphilis, which has led to a 700% increase in congenital syphilis cases since 2015.

Public health funding for all sexually transmitted infections, excluding HIV, has been stagnant for decades, at about US$160 million annually. When accounting for inflation and rising costs, this has resulted in a 40% reduction in spending power today.

Unfortunately, each year Congress suggests cutting funding to both STI and healthcare access programs. These cuts have largely not been........

© The Conversation