Since it came onto the scene in 1943, penicillin has made syphilis a thing of the past — almost. Now, the sexually transmitted disease is making a comeback in the U.S. and there's a shortage of the medication used to treat it.
Pfizer, the company that supplies it, says it's experiencing "an unanticipated manufacturing delay," and in a letter to consumers wrote that it would be providing just one-third of the usual monthly demand until July.
The medication, called Bicillin L-A, is the recommended treatment for people with syphilis. It's also the only one available for pregnant women who are infected with or exposed to syphilis, which is caused by the bacterium Treponema pallidum. But the antibiotic can be used against other bacteria, like the one that causes strep throat.
The Centers for Disease Control and Prevention has asked that health care providers save the drug for people with syphilis, especially pregnant women. Even if a woman does not show symptoms, the infection can pass to a fetus during pregnancy and can cause miscarriage, stillbirth and complications including deformed bones, seizures and blindness.
"And the real tragedy is that it is a treatable infection," says Dr. Sarah Kidd, a medical epidemiologist with the CDC's Division of STD Prevention.
She's on a surveillance team that tracks syphilis transmission in the U.S. There were 20,000 cases in 2014. The vast majority of those patients would be treated with one to three injections of Bicillin L-A, also called penicillin G benzathine. Kidd says according to preliminary data, the climb continued in 2015, a trend that started in 2000.
"It is becoming a more common infection," says Kidd. "And because this is the preferred regimen for treatment for syphilis, it really is a critical problem for syphilis control."
It's routine for pregnant women to be tested for syphilis during their first prenatal visit and, if infected, to receive a course of Bicillin L-A. But after declining in the U.S. for four years, the incidence of babies born with syphilis rose sharply after 2012, likely due to a lack of prenatal care. In 2014, about 500 babies were born in the U.S. with syphilis.
Kidd says the CDC is working with state health departments to identify where there are shortages and send supplies of the medication there.
"If [patients] have to go to a different clinic or place to get their Bicillin shot, it just increases the odds of transmission further before they're cured. So it's another potential barrier in the prevention and control of syphilis."
This particular shortage is no rare event, says Erin Fox, director of the Drug Information Service at University of Utah Health Care, which tracks drugs across the country.
"Unfortunately there are constantly drug shortages. Right now we are following just over 200 active shortages," she says. That's a lot better than the 300 she was tracking before, she says, "But it's still something that hospitals are facing on a daily basis."
Most shortages are due to manufacturing problems, Fox says, like rusting machinery, moldy walls or particles getting into vials that are supposed to be sterile. Some of those events can take months or even years to clear up.
Generic drugs that come in the form of a shot, like Bicillin L-A, are particularly prone to shortages. They're cheap and hard to make, so only a few companies produce them. And when it comes to Bicillin L-A, Pfizer is the only supplier.
"The supply chain is really fragile because we really only have just a small number of companies that make these products," says Fox. "And so when you have a small number of factories and one has a problem, there just isn't additional capacity to make up that difference."
And the market is consolidating. Last year, Pfizer bought Hospira, one of the few U.S. companies manufacturing injectable generic drugs.
Fox says that patients usually get the medications they need because hospitals and pharmacies scramble to get the stocks to the right place, or to prescribe an alternative. But it's hard to plan for drug shortages. Fox says it's a little like preparing for natural disasters.
"Almost every hospital has a set plan for how they deal with drug shortages. The surprise that happens on a daily basis is 'What product is going to be short?'" she says. Often, the first time hospitals and pharmacies find out about a shortage is when a shipment of medications never arrives.
Luckily, says Fox, this situation appears to be short-term. Pfizer says the supply should be back to normal in July.