The number of babies born infected with syphilis increased in Colorado last year, but not by as much as state officials feared when they sounded the alarm in April.

The 2024 statistics aren’t finalized yet, but it appears about 60 babies had congenital syphilis, which means they got the infection during pregnancy or at birth. The number of cases had increased sharply over the previous five years, from seven in 2018 to 51 in 2023.

“What it’s looking like is a stabilization” and, hopefully, a decline will follow, state epidemiologist Dr. Rachel Herlihy said Friday.

In April, the Colorado Department of Public Health and Environment issued an order requiring health care providers to offer testing to patients in the first trimester and third trimester, when they gave birth, or if they suffered an infant death or stillbirth after 20 weeks of pregnancy. (Miscarriages in early pregnancy are common, but later losses are rarer and may point to a medical problem for the mother.)

At the time, Colorado had recorded 25 cases, including seven infants who were stillborn or died within months of birth from complications of the infection, and Herlihy said that the state could have more than 100 cases if nothing changed.

Babies have the best chance of avoiding complications from syphilis if their mothers get treatment at least 30 days before their birth, said Dr. Sara Saporta-Keating, associate medical director of infection prevention and control at Children’s Hospital Colorado. Someone with a new infection typically needs only one shot of antibiotics, while people who have had the disease longer need three.

Without treatment, the bacteria invade most parts of the body, causing severe inflammation that eventually results in disability or death, Saporta-Keating said.

Some babies clearly are sick at birth, while others appear healthy but later show damage to their brains, eyes, ears or bones.

“The goal is to treat them before they have any (negative) outcomes,” she said.

While 50 or 60 babies represent a small fraction of all children born in Colorado, the state needs to keep focusing on identifying and treating parents because of the severe consequences, Saporta-Keating said.

“Those are 50 babies that wouldn’t have had to have a 10-day stay in the ICU,” which is standard for those not treated before birth, she said.

“This is a preventable disease, and if we can keep 50 babies from having to go through that, I think it’s worth it.”

Previously, Colorado required health care providers to offer syphilis testing during the first trimester, or whenever the patient started prenatal care.

Last session, lawmakers passed a bill directing the state Board of Health to come up with permanent rules for syphilis testing during pregnancy. The rules, which took effect Jan. 14, are essentially the same as those set in last year’s public health order.

Around the same time that state health department issued its order, the American College of Obstetricians and Gynecologists released new guidance, calling for providers to test patients twice during pregnancy and at birth. Some patients who test negative or get treatment early in pregnancy get infected again, particularly if their partners haven’t received antibiotics.

Hopefully, universal testing will reduce the stigma associated with looking for a sexually transmitted infection and encourage more patients to agree, Saporta-Keating said.