Insights on the Rising Rates of Syphilis in the United States

Announcer:
You’re listening to NeuroFrontiers on ReachMD. On this episode, we’ll hear from Dr. Ina Park, who’s a Professor of Family Community Medicine at the University of California San Francisco School of Medicine She’ll be discussing the recent rise of syphilis in the United States, which was her topic at the 2024 Conference on Retroviruses and Opportunistic Infections. 

Dr. Park:
So for the past five years, we’ve seen pretty astronomical increases in syphilis, and in fact, those increases actually started around the year 2000, but just in the past five years, we’ve seen an 80 percent increase in the number of cases of syphilis.  So in 2022, the CDC reported that there were over 207,000 cases, which was an 80 percent increase from the five-year-period before.  And I think the worst of this is the epidemic of congenital syphilis, and so we’ve seen almost a 200 percent increase in cases in the past five years, so now we’re over 3,700 cases of congenital syphilis. 

When we think about who’s affected by syphilis in the US, certainly, a huge burden of the cases occurs in men who have sex with men.  And so what we’re looking at right now is not only are syphilis case counts extremely high, but when we look at rates in men who have sex with men and what the estimated rates are, they’re similar to what they were actually in the ‘80s before the advent of HIV.  And so we did have a huge decline in syphilis among gay men in the ‘80s because of HIV and people using condoms quite a lot more frequently than they are now because of concerns about sexually transmitted infections, so we saw a huge dip in syphilis.  And then now with the advent of other prevention interventions, such as HIV PrEP, people are using condoms a lot less, and so I think syphilis has certainly risen in men who have sex with men to those really high levels once again.

The other population I want to tell you about is women of reproductive age have historically in the US not been a huge population of concern around syphilis, and we almost eliminated congenital syphilis in 1999 and 2000, and about 80 percent of the counties in the US had no syphilis reported in those years.  But then as syphilis increases in the population in general, women of reproductive age, unfortunately, are getting affected, and part of the reason for that is an intersection with the crystal meth epidemic, especially in the West, as well as lack of access to care and poverty.  So the group most affected by congenital syphilis in terms of the highest rates are American Indian, Native American, Alaska Native communities, but certainly, we’ve seen increases in every race, ethnicity, among women as well.

When we think about issues related to treatment and why the infection may be spreading is that we have also had a shortage of the recommended treatment for syphilis, which is benzathine penicillin.  And hopefully, in the third quarter of this year, that shortage should be ending.  But unfortunately, we’ve been having to ration some of that medication and reserving it for the cases that are highest priorities, such as pregnant women, for example. 

In regards to a response to the shortage of benzathine penicillin, the FDA did allow the importation and sale of a formulation of benzathine penicillin from France called Extencilline, and so that is available.  I did want folks to know about that, as well as the fact that on the CDC’s website if you look up penicillin shortage, you’ll get up-to-date news about supply, as well as contact information for Pfizer if you’re having trouble getting the medication, and I do know that folks have been successful getting it that way. 

When it comes to diagnosis, I have to say we are missing a lot of syphilis because syphilis really can look like anything, and most of the time it looks like nothing.  And so one of the things that CDC has recommended is they’ve clarified a recommendation that they’ve had for years, which is that people who are living in high-risk areas should be tested for syphilis routinely, so that’s people of all genders between 15 and 44.

In terms of what’s being done now to curb the spread, what I would love to see that we do not have yet is molecular detection tests, such as a PCR, nucleic acid amplification test.  Those are research use only, and some laboratories have created a home-brew PCR-type test, which you can actually use on genital lesion because you can’t tell just from looking at a lesion whether or not it’s herpes; it could be Mpox; it could be syphilis.  So we really need to be catching those lesions when they’re at their most infectious because that primary stage, which only lasts a couple weeks, and then the lesion will heal, is when the person is most likely to transmit, and so I would love to be able to see us do better with diagnostics.

For everyone listening out there, if you find yourself in a bind and having a difficult time interpreting serologies, I would invite everybody out there listening to send a consult.  It’s called the STD Clinical Consultation Network.  It’s STDCCN.org, and you can submit a consult anytime, and we will get back to you between one and five business days, depending on how urgently you want a response.