Rates are so bad in Native American communities that public health experts have asked the federal government to declare an emergency. Inadequate prenatal care may be partly to blame.

The drug is the go-to treatment for syphilis and the only one recommended for pregnant people. But a shortage of the injectable drug has prompted some public health agencies to ration it.

Cases increased by nearly 80% to more than 207,000 between 2018 and 2022, according to the CDC. Rates increased among all age groups, including newborns, and in all regions of the country.

Unless mothers are treated during pregnancy, newborns can sicken, die or face lifelong disabilities. The CDC is urging public health providers to connect more people to testing and medication.

The shortage comes as there has been a steady increase in rates of syphilis since 2000. Inventory can start depleting as early as this month, Pfizer said.

Syphilis cases in California have contributed to soaring national caseloads of sexually transmitted diseases. Experts point to the advent of dating apps, decreased condom use and an increase in meth.