Colorado is experiencing an alarming spike in syphilis among newborns, leading the state to issue a public health order Thursday aimed at curbing the disease’s spread through wider testing.

In 2023, 50 infants in Colorado were born with syphilis, up from only seven in 2018. So far this year, the state is halfway to last year’s total, with five infected babies who were stillborn and two who died in their first months of life, state epidemiologist Dr. Rachel Herlihy said.

“We’ve already had 25 cases so far this year, putting us on track to have maybe 100 cases,” she said at a news conference, addressing what Gov. Jared Polis’s office called a “growing epidemic.” 

Syphilis is a sexually transmitted infection that sometimes causes no symptoms in adults, though the bacteria can eventually damage the heart and brain if a person doesn’t receive treatment. But roughly two out of five babies born to infected mothers will be stillborn or die in infancy, and those who survive are at risk of intellectual disability, bone deformities and other lifelong health problems, Herlihy said.

The new public health order from the Colorado Department of Public Health and Environment requires all health care providers to offer syphilis testing at least three times to pregnant patients: in the first trimester, in the third trimester and at birth.

Nearly all insurance plans cover the testing, and people without insurance can receive it for free at public health clinics or by ordering a home test kit.

“We hope to save many babies from death and suffering,” Polis said at the news conference.

On Thursday, the American College of Obstetricians and Gynecologists issued a recommendation that all pregnant patients receive testing three times. Previously, it only recommended more than one test if a patient had certain risk factors for getting infected while pregnant.

“The cases of congenital syphilis are definitely climbing, and they’ve been climbing over the last 10 years. And it’s completely preventable… It’s unacceptable,” said Dr. Laura Riley, who chairs the Department of Obstetrics and Gynecology at Weill Cornell Medicine and helped with the guidance. “We need to be able to do better diagnostics and treatment.”

The Colorado order also requires offering tests to prisoners who are pregnant, and to people who have experienced a stillbirth after 20 weeks of pregnancy, when spontaneous miscarriages are rare. While it would be too late for that particular fetus after a stillbirth, antibiotic treatment would protect the mother, her sex partners and any future pregnancies.

Patients and prisoners aren’t required to undergo testing if they don’t want to, but their providers have to give them the option, said Jill Hunsaker Ryan, executive director of the state health department. State law already required that providers offer everyone syphilis testing in the first trimester.

Last year, 3,266 people in Colorado received a syphilis diagnosis, which was a 5% increase over the previous year and more than three times the number diagnosed in 2018. Most of the diagnoses are still in men, because the bacteria became entrenched in the community of gay and bisexual men. About one-third are in women, though, and diagnoses have risen faster among women than among men.

Nationwide, syphilis diagnoses reached their highest rate since at least 1950 in 2022, according to the Centers for Disease Control and Prevention. Cases peaked in the 1940s, before antibiotics became widely available, and fell throughout the 20th century.

People of color and those who lack access to reliable health care, such as the homeless population, have been hit disproportionately hard in the resurgence over the last few years.

Earlier this year, the state health department asked for $8 million over four years to fund an opt-out syphilis screening program at two hospital emergency departments in Denver and Pueblo County, which both have a significant share of new infections.

The department also proposed to distribute rapid tests to organizations that work with at-risk people; to fund delivering treatment to some people in their homes; and to build up a stockpile of the antibiotics used to treat syphilis. Most antibiotics are cheap, but the best option for syphilis, Bicillin, is relatively expensive and in short supply, so providers don’t always opt to stock it.

The legislature appropriated about $1.9 million for the first year of the syphilis response, and will have to vote on additional money in subsequent years.

The state and the Pueblo Department of Public Health and Environment already run a small pilot program to bring treatment to people in their homes. Jails in Pueblo, El Paso and Jefferson counties also have started screening female prisoners and offering treatment to anyone who tests positive.

Pueblo County Sheriff David Lucero said about one-quarter of the 634 people his department has screened so far tested positive, and seven were pregnant at the time of their positive test. The Pueblo County jail has a partnership with the local health department to follow up if someone returns to the community before completing treatment, he said.

“Without a doubt, this program saves lives,” Lucero said.

The biggest driver of the increase in congenital syphilis seems to be that mothers aren’t getting early prenatal care, which could identify and cure the infection, Herlihy said. The mothers of babies born affected this year have higher rates of previous incarceration, untreated addiction and homelessness than the general population, she said.

“The risk factors we’re seeing are really driving the actions we’re taking,” she said.

The Associated Press contributed to this report.

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