The number of expecting mothers with syphilis in the United States more than tripled between 2016 and 2022, according to a recent CDC study.
Between those years, the overall rate of syphilis among pregnant women in the country increased from 87.2 per 100,000 births to 280.4 per 100,000 births.
Syphilis cases have risen to levels not seen since the 1950s among the U.S. general population, according to the CDC.
Cases of the bacterial infection have gone up by 17 percent in the last year and by 80 percent over the past five years.
Syphilis cases have risen among all U.S. mothers regardless of race or ethnicity, with the largest increase occurring among American Indian and Alaska Native mothers — 159.7 cases per 100,000 births in 2016 to 1,410.5 cases per 100,000 births in 2022.
White non-Hispanic mothers saw the second-largest uptick in cases with incidents of the disease rising from 36.8 cases per 100,000 births in 2016 to 152.8 cases per 100,000 births in 2022.
Expecting mothers of all age groups have also experienced increases in syphilis cases with the largest increase among mothers younger than 20 years old—107.3 per 100,000 births in 2016 to 418.6 per 100,000 births in 2022.
As a result, more newborns are contracting syphilis, with over 3,700 babies born with the illness in 2022—the most in the last 30 years.
The United States came close to eradicating syphilis in the 1990s, but rates of the disease began to creep up in the early 2000s, increasing almost every year until 2022, according to the CDC.
Without treatment, syphilis is life-threatening and can cause brain, heart and other organ damage in adults. Congenital syphilis, or when the disease is passed from mother to baby during pregnancy, can cause stillbirth, preterm birth, anemia as well as brain and nerve damage.