As syphilis cases continue to spike across the U.S. — with some cities and states recently reporting outbreaks — there is a growing concern about the availability of Bicillin, the injectable penicillin that is used to treat the sexually transmitted infection in adults and kids.

The city of Houston officially declared a syphilis outbreak on July 13. It cited a 128% increase in cases among women and a nine-fold rise in congenital syphilis in Houston and Harris County, according to an announcement from the Houston Health Department.

Last month, the Food and Drug Administration (FDA) announced that it expects a "limited supply and impending stock out situation" for select Bicillin medications.

Spike in syphilis cases

Cases of syphilis, a bacterial infection that is spread through sexual contact or from a mother to an unborn child, have been on the rise in the U.S. for the past several years.

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Since 2017, all stages of the disease have risen by 74%, with over 176,000 cases reported in 2021, according to the Centers for Disease Control and Prevention (CDC).

Syphilis test

Cases of syphilis, a bacterial infection spread through sexual contact or from a mother to an unborn child, have been on the rise in the U.S. for the past several years. (Getty Images)

Between 2020 and 2021 alone, syphilis cases increased by 32%.

Cases of congenital syphilis, which occurs when a mother passes the infection on to her baby during pregnancy, also rose by 32% — resulting in 220 stillbirths and infant deaths.

Certain regions of the country have seen an even more dramatic spike. In Texas, congenital syphilis cases have risen by 650% since 2016, per the Texas Department of Health and Human Services.

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James Hodges, M.D., an internist in Waco, Texas, has been in practice for more than 20 years.

He shared with Dr. Marc Siegel, professor of medicine at NYU Langone Medical Center and a Fox News medical contributor, that two Texas prisons have seen a surge in positive syphilis cases among their women’s intake units.

"They’ve seen somewhere in the neighborhood of twice the amount compared to just 18 months ago," he told Fox News Digital. "Those inmates are mostly coming from Houston and San Antonio, and more now from Dallas-Ft. Worth.

A syphilis billboard in Los Angeles, California

Since 2017, all stages of the disease have risen by 74%, with more than 176,000 cases reported in 2021, according to the Centers for Disease Control and Prevention (CDC). (FREDERIC J. BROWN/AFP via Getty Images)

"They are not concerned about it, and are often quoted as saying, ‘It’s no big deal, there is a cure.’"

Hodges estimated that young White women and young Black women comprise the largest share of cases in women’s prisons.

Some county sheriffs he spoke with were unaware of the syphilis problems, as the county jails don’t typically test for the disease, Hodges added.

Syphilis screenings at the border

The CDC provides guidance for all physicians performing medical screening examinations for immigrants and refugees entering the U.S., according to Letitia Bligh, the agency’s health communications specialist in Atlanta.

Immigrants with certain communicable diseases are not eligible to obtain a visa or enter the country, according to Section 212(a)(1)(A) of the Immigration and Nationality Act (INA).

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Syphilis is one of the diseases on that list, in addition to tuberculosis, gonorrhea, COVID-19, polio, smallpox, pandemic flu and others.

The CDC "does not track diseases by immigration status."

"CDC has comprehensive surveillance systems to track communicable diseases (diseases that can be transmitted to others) for people in the U.S.," Bligh said. "However, CDC does not track diseases by immigration status."

Between 2014 and 2019, approximately 445 out of every 100,000 tested immigrants and refugees were positive for some form of syphilis, per the CDC.

Migrants at border

Immigrants with certain communicable diseases are not eligible to obtain a visa or enter the country. (Getty Images)

The CDC website states that "syphilis tests must be performed at the time of the immigration medical examination and at the laboratory stated in the panel physician agreement" — but some doctors are skeptical.

"They are not being tested for COVID as they come across [the border], much less for syphilis," Hodges, the Texas physician, told Siegel.

The Texas-Mexico border region "has the lowest rates of gonorrhea and primary and secondary syphilis, but has the highest rate of congenital syphilis," according to the Texas Department of State Health Services.

US Mexico border

"Out of the reported 25,469 syphilis cases in Texas during 2022, 143 of those cases were reported to acquire the infection from Mexico," said a spokesperson for the Texas Department of State Health Services. (Getty Images)

A spokesperson for the Texas Department of State Health Services told Fox News Digital on Thursday that they are unable to quantify the impact of immigration on reported syphilis cases in Texas.

"The data source used for geographical reporting of syphilis diseases within Texas is the client’s home address reported by the provider," the spokesperson continued. 

"We attempt to obtain [information about] sexual partners from newly diagnosed individuals to facilitate their testing and treatment, but we’re unable to distinguish Mexico residents from Texas from the information provided."

The spokesperson also said, "Of the reported 25,469 syphilis cases in Texas during 2022, 143 of those cases were reported to acquire the infection from Mexico."

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Dr. Jason E. Zucker, assistant professor of medicine at Columbia University Irving Medical Center in New York, told Siegel that while he’s unsure of the exact percentage, he does treat some immigrants with syphilis.

"That said, syphilis rates in the domestic population have been increasing for years — so anecdotally, while we are seeing some recent immigrants, the majority of our patients with syphilis are not recent immigrants," he said.

Pfizer says Bicillin is 'limited' but no official shortage

Pfizer is the only pharmaceutical company that makes Bicillin, producing the drug in its Rochester, Michigan, facility.

A Pfizer spokesperson told Fox News Digital said the drug is "definitely taxed" and in "constrained supply," but denied that there is an official shortage.

Pregnant woman syphilis test split

Cases of congenital syphilis, which occurs when a mother passes the infection on to her baby during pregnancy, rose by 32% between 2020 and 2021. (iStock)

In 2022, during the convergence of RSV, flu and COVID, there was a shortage of the popular antibiotic amoxicillin. This led doctors to begin prescribing Bicillin as a backup to treat strep throat and other bacterial infections in children, which hadn’t happened before, the Pfizer rep said. 

Those factors, coupled with the spike in syphilis cases, led to the dwindling supply.

"We’re pushing hard to produce more Bicillin and supply the market," the spokesperson added. 

After amoxicillin became widely available again, Pfizer switched its focus to making more of the adult form of Bicillin, pausing production of the children’s version.

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"We made a decision to deprioritize the pediatric version of the drug — which is rarely ever used by pediatricians for antibiotic purposes with kids — and to prioritize the adult version for the patient community that needs it most," the spokesperson said. 

"It's vital for pregnant women with syphilis to get the drug, because if they don't, their babies could die or be born with birth defects. So it was a relatively straightforward call."

The pediatric version is expected to run out eventually, the rep confirmed, but he also said, "There will not be a stock-out of the adult drug."

Currently, the drug is "not as readily available as we would like, but there is supply," he said.

Mark C. Poznansky, M.D., PhD, an infectious disease physician at Massachusetts General Hospital and an associate professor at Harvard University, told Siegel that the potential shortage of Bicillin didn’t affect them much until the past few weeks.

"The hospital does still have some Bicillin, and we are able to procure some from the state directly, but currently the drug is being prioritized for pregnant people with syphilis and their contacts, or people who, for whatever reason, cannot receive doxycycline," he explained. 

"The state supply can also be used for people with primary/secondary/early latent syphilis."

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At Columbia University, physicians are seeing an increase in syphilis cases across gay, bisexual and other men who have sex with men (MSM) as well as people born female, Zucker told Siegel.

"That is coupled with the nationwide shortage of Bicillin, driven by increased demand, which has led us to develop protocols to try and reduce Bicillin usage whenever possible," he said.

In Nashville, Tennessee, Dr. Zachary Hoy, a board-certified pediatric infectious disease specialist and medical director at Pediatrix Medical Group, mainly sees cases of congenital syphilis, which happens when an infant is born to a mother with the infection.

Pfizer

Pfizer is the only pharmaceutical company that makes Bicillin, the penicillin drug that treats syphilis. (iStock)

"Currently we have not experienced a shortage of Bicillin at my facility, but there are some hospitals in Nashville that are concerned about a shortage," he told Fox News Digital.

Pfizer expects to reach "full recovery mode" — which is when there is an "ample backup supply" of six to eight weeks’ worth of excess supply on the shelves — by mid- to late-2024, the company spokesperson told Fox News Digital.

What to know about syphilis: Diagnosis, treatment, prevention

The first sign of syphilis is usually a painless sore on the mouth, genitals or rectum, according to the Mayo Clinic. Later symptoms can include a body rash, hair loss, muscle aches, sore throat, fever and swollen lymph nodes. 

In its early stages, syphilis can be treated with an injection of penicillin (Bicillin).

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If left untreated, up to 30% of people may develop tertiary syphilis, which can eventually damage the brain, nerves, eyes, heart, blood vessels, liver, bones and joints, per the Mayo Clinic. 

With congenital syphilis, an infected mother can pass the disease on to her unborn baby, which can cause fetal death, premature birth or birth defects.

Premature baby

With congenital syphilis, an infected mother can pass the disease on to her unborn baby, which can cause fetal death, premature birth or birth defects. (iStock)

Those most at risk include people who engage in unprotected sex, have sex with multiple partners, are men who have sex with men, or are infected with HIV, the Mayo Clinic states.

There is currently no vaccine for syphilis.

"Many sexually transmitted infections are treatable, but have to be diagnosed and followed with a treatment plan," Hoy told Fox News Digital. 

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"STI screening is free or at a significantly reduced cost at public health departments," he added. "Some screening can even be done via urine or swab testing and may not require a blood draw."

Those who suspect they may be infected should seek screening right away, the doctor advised.