The number of babies born with congenital syphilis rose 900% over the course of five years in Mississippi, the state that already had the highest infant mortality rate in the U.S. in 2020.

Congenital syphilis occurs when a pregnant woman with syphilis passes the sexually transmitted infection on to their baby during pregnancy. Pregnant women with untreated syphilis have an 80% chance of giving it to their child.

Babies born with congenital syphilis can have serious birth defects, including deformed bones, severe anemia and even deafness or blindness, according to the Centers for Disease Control and Prevention. About 40% of babies born to mothers with untreated syphilis are stillborn or die shortly after birth.

Cases in Mississippi have increased from 10 in 2016 to 102 in 2021, according to hospital billing data given to NBC. Experts attribute the spike to the lack of access to prenatal care that many pregnant women in Mississippi experience.

Maternal health nonprofit March of Dimes has classified more than half the counties in Mississippi as “maternal care deserts,” or places in which prenatal care is lacking or nonexistent. The fact that Mississippi has the highest poverty rate in the country doesn’t help — pregnant people often don’t want to miss work to visit the doctor and have to wait for Medicaid approval, according to NBC.

The disease disproportionately affects the Black community in Mississippi. Seventy percent of babies born with syphilis in 2020 were Black, even though 42% of newborns were Black, NBC reported.

This surge is not limited to Mississippi. The Centers for Disease Control and Prevention says cases across the U.S. have more than doubled from 2017 to 2021.

The infection, however, is curable. It can be treated with penicillin in both adults and infants. 

Mississippi OB-GYN Nina Ragunanthan said per NBC that lowering case rates is “completely attainable” but “takes money.” State epidemiologist Paul Byers said the Department of Health is considering making syphilis screenings mandatory for pregnant women, as have most other state health departments.