Episode 112: Syphilis Basics - a podcast by Rio Bravo Family Medicine Residency Program

Introduction: False positive RPR. 
By Hector Arreaza, MD. Read by Alinor Mezinord, MS III, Ross University School of Medicine.  

Today we will talk about syphilis. Significant research has been done to determine the origin of this ancient infection. Some experts support that syphilis originated in the New World (the Americas) because the first cases in Europe were reported after the Christopher Columbus crew returned from their expeditions. On the other hand, some people defend the idea of the origin of syphilis in the Old World. 

Whatever its origin, syphilis is still affecting thousands of people worldwide. According to the World Health Organization, “syphilis in pregnancy is the second leading cause of stillbirth globally and also results in prematurity, low birth weight, neonatal death, and infections in newborns.”[1] The cases in the US are not as high as in other countries, but certain areas have cases higher than the national or state average. Such is the case in Kern County. Our incidence of syphilis is higher than the national average.

That’s why it is important to screen for this disease. RPR is the most common test to screen for syphilis; however, it may not be completely accurate. RPR is a non-treponemal test that can cause false positive results. On December 20, 2021, the CDC released a letter announcing an FDA alert regarding a high RPR false positive rate when done with Bio-Rad Laboratories BioPlex 2200 Syphilis Total & RPR kit. You may not know which kit was used for the test, but you need to know what to do with a positive RPR. Some conditions associated with false positive RPR include COVID-19 vaccines, tuberculosis, endocarditis, rickettsial disease, recent immunizations (smallpox), and pregnancy. 

In case of RPR positive, you need to confirm syphilis with a treponemal test, which will be more reliable regardless of the possibility of a false positive RPR. We still need to screen because syphilis continues to increase in our nation. I hope you enjoy this episode.

You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.

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Latent Syphilis. 
By Carol Avila, MD. Comments by Hector Arreaza, MD.

 

Dr. Avila: I had the amazing opportunity to do inpatient pediatrics during my first rotation at a local hospital, and I often treated patients with neonatal syphilis. I was curious to know what is happening in this area (Bakersfield) that made syphilis (seems to me) a very frequent diagnosis of admission in peds, especially because newborns are impacted by a preventable disease.

Epidemiology:

The latest update available on the CDC website is the 2020 Surveillance Report of Nationally Notifiable STDs which showed:

-In 2020, the national rate of syphilis was about 40 per 100,000 population (all stages).

-The rate of national congenital syphilis was about 57 cases per 100,000 live births.

-During that year, California was ranked #7 for primary and secondary syphilis (P&S), with a 19.5 per 100,000 population. Nevada was the number #1 state.

Local data:

In 2018 data, the Kern County Public Health Services Department reported:

-A total of 1,520 cases of syphilis (all stages) were diagnosed during that year, about 4 cases/day. It is important to mention that there was a spike in the number of cases of syphilis by 86% compared to the prior year, 2017.

-In 2020, 250 cases of congenital syphilis per 100,000 live births were reported in Kern County. Significantly higher than the national average (mentioned above, 40 cases per 100,000 residents). 

-For primary and secondary syphilis, Kern County was 62% higher than the state average, with almost 35 per 100,000 population, and was ranked #6 in the state of California. 

-San Francisco was ranked #1.

-Bottomline: The rate of syphilis and congenital syphilis in Kern County is higher than the state and national average.

Definition:

Syphilis is a systemic bacterial infection caused by the gram-negative spirochete Treponema pallidum.

 

Transmission:

Syphilis is well known as a sexually transmitted disease; however, while many cases happen due to sexual activity, there are a few other ways that syphilis can also be spread.

-It can be transmitted during pregnancy, resulting in congenital syphilis.

-Also, passing on syphilis via blood transfusions was very common but is now rare thanks to blood supply screening.

-Syphilis transmission is also possible through an organ donor, which nowadays is very rare.

-Before healthcare providers were wearing gloves as a standard precaution, it was common for syphilis lesions to appear on their fingers and noses.

-It can also be transmitted through close and repetitive contact with mucosal or skin lesions of people with active syphilis.

Classification:

-Syphilis is divided into stages based on clinical findings. Primary, secondary, and tertiary.

-The latent phase occurs between secondary and tertiary. 

-Patients pass through secondary syphilis and may not realize it.

-The most contagious stages are primary and secondary, and syphilis could still be contagious in the early latent phase.

-Easy classification: Early (primary, secondary, early latent); Late (tertiary and late latent); Neurosyphilis (which occurs any time).

Primary syphilis:

-It usually happens 3 weeks after the initial contact with the spirochete, but it can also be seen after 90 days. The bacteria will destroy the local tissue when we see the syphilitic chancre, a painless, well-demarcated lesion with firm, indurated margins. It might go unnoticed; without treatment, the bacteria will spread to the bloodstream, and the infection will progress to the secondary stage.

Secondary syphilis:

-In the secondary stage, the patient can have a wide variety of signs and symptoms. General constitutional symptoms are common; however, it is characterized by a body-wide rash, prominent in palms and soles. This rash can be macular, papular, or pustular; patients can also develop patches in oral mucosa and tongue, as well as wart-like sores called condylomata lata.

 

Tertiary syphilis:

-In the pre-antibiotic era, 15 to 30 years after the initial infection, patients could develop any of the three forms of tertiary syphilis. 

-Cardiovascular syphilis involves the ascending thoracic aorta. Patients may present with aortic

aneurysm or left heart failure. 

-Gummatous syphilis is uncommon, but it is especially important in patients coinfected with HIV. Gummas can appear in the skin, bones, or internal organs. 

-Central Nervous System syphilis presents with general paresis, tabes dorsalis, meningitis, hearing and vision loss, and dementia.

Latent syphilis:

-It occurs when the patient has positive serology for T. pallidum, but the patient is asymptomatic. 

-Latent syphilis can also be divided into early latent (when the primary infection occurred within the previous 12 months); and late latent syphilis (when the primary stage happened more than 12 months ago.)

-Differentiating early and late latent syphilis is vital because the treatment will differ.

Congenital syphilis:

-The infection occurs during pregnancy.

-It can cause miscarriage, stillbirth, or birth defects like nasal cartilage destruction, and frontal

bossing, among others.

 

Screening and Diagnostic Testing:

-The USPSTF recommends screening asymptomatic, nonpregnant adults and adolescents at increased risk for syphilis infection (Grade A).

-The USPSTF recommends early screening for syphilis infection in all pregnant women. as early as possible when they first present to care. 

-Repeat screening: The CDC and joint guidelines from the American Academy of Pediatrics (AAP) and the ACOG endorse repeat screening, especially for women at risk, early in the third trimester (at about 28 weeks of gestation) and again at delivery.

-High-risk patients include men who have sex with men (MSM) and men and women living with HIV. 

-Also, people with a history of incarceration, a history of commercial sex work, certain racial/ethnic groups (African Americans and Hispanics), and being a male younger than 29 years.

How to screen: 

-Initial screening should be done with a nontreponemal test (RPR or VDRL); if positive, a treponemal test (TP-PA or FTA-ABS) would be the next step. 

-Nontreponemal tests can be positive in patients with preexisting conditions, e.g., collagen vascular diseases, pregnancy, malignancy, tuberculosis, etc.

-The USPSTF also refers to the reverse sequence screening algorithm, where we perform a treponemal test first in those patients that could be missed after a nontreponemal test, for example, people who are homeless, also in nontraditional and nonclinical settings. 

-A treponemal test will be followed by a nontreponemal test, however, there is no evidence of the accuracy of this screening algorithm, so it is an open field for researchers.

-Remember that most patients will have positive antibodies for life, irrespective of treatment or disease stage.

Treatment:

-One word: Penicillin is the treatment of choice.

-Additionally, every patient diagnosed with primary and secondary syphilis should be tested for HIV and other sexually transmitted diseases at the time of diagnosis.

 

Primary, secondary, and early latent syphilis: Benzathine penicillin G, 2.4-million-unit IM, in a single dose.

-Children/Infant age > 1 month of age: Benzathine PCN G, 50,000 units/kg body weight IM up to 2.4 million-unit in a single dose. 

-Children > 1 month with P&S syphilis should be evaluated for sexual abuse.

Arreaza:

-Pregnancy: Treatment is still penicillin G, if there is a penicillin allergy, desensitization should be done in a controlled setting.

-In non-pregnant with PCN allergy- alternatives are doxycycline 100 mg BID x14 days or Ceftriaxone 1 G daily IM or IV for 10-14 days.

-For P&S syphilis: clinical and serological evaluation should be done at 6 to 12 months after treatment.

 

Late latent syphilis and tertiary: Benzathine penicillin G, 7.2-million-unit total, administered as 2.4 million units IM each week x3 doses. (2.4 x3 = 7.2). A good strategy is to assume all latent syphilis are late latent. 

-Follow up with a quantitative nontreponemal serologic test at 6, 12, and 24 months, and compare this

titer with the initial titer at the time of diagnosis.

-Special recommendation: Check RPR titer the same day you give the first dose of penicillin.

Neurosyphilis: 

-CSF examination is recommended if neurologic findings are present.

-If neurosyphilis is confirmed, it will require aqueous penicillin G, 3-4 million units IV every 4 hours for 10-14 days. Alternative ceftriaxone 2 G IV daily x14 days. Get guidance from an ID specialist. We will continue talking about syphilis in another episode, which was an excellent introduction.

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Conclusion: Now we conclude episode number 112, “Syphilis Basics.” Dr. Avila raised our awareness of syphilis in our community and the importance of screening all adolescents and adults at risk of infection, and especially ALL pregnant persons, during their first prenatal visit or as early as possible. Timely treatment with penicillin is important to prevent late complications of syphilis and especially to prevent the devastating consequences of congenital syphilis. This week we thank Hector Arreaza, Carol Avila, and Alinor Mezinord. Audio edition by Adrianne Silva.

Even without trying, every night, you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you; send us an email at RioBravoqWeek@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. See you next week!

References:

1. Data on syphilis, The Global Health Observatory, World Health Organization, who.int, https://www.who.int/data/gho/data/themes/topics/topic-details/GHO/data-on-syphilis,  accessed September 14, 2022.

 

2. Center for Disease Control and Prevention. (2022, April 11). National Overview of STD.  https://www.cdc.gov/std/statistics/2020/overview.htm#CongenitalSyphilis.

 

3. STDs in Kern County, Kern County Public Health Services Department, STDS in Kern County 2018, https://kernpublichealth.com/wp-content/uploads/STDs-in-Kern-County-2018-slide-set-comparison.pdf, downloaded on Sep 12, 2022.

 

4. Center for Disease Control and Prevention. (2022, April 4). Reported Cases and Rates of Reported Cases by State, Ranked by Rates, United States, 2020. https://www.cdc.gov/std/statistics/2020/tables/13.htm

 

5. Morgen, Sam, Reported cases of STDs in Kern County dropped in 2020, but decrease could be misleading, The Bakersfield Californian, Apr 17, 2022, bakersfield.com, https://www.bakersfield.com/news/reported-cases-of-stds-in-kern-county-dropped-in-2020-but-decrease-could-be-misleading/article_6e7d8d36-bd18-11ec-a98f-7f247bc2517e.html.

 

6. U.S. Preventive Services Task Force. (2016, June 7). Syphilis Infection in Nonpregnant Adults and Adolescents: Screening. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/syphilis-infection-in-nonpregnant-adults-and-adolescents.

 

7. Center For Disease Control And Prevention. (2022, July 21). Sexually Transmitted Infections Treatment Guidelines. https://www.cdc.gov/std/treatment-guidelines/syphilis.htm.

 

8. Calonge N; U.S. Preventive Services Task Force. Screening for syphilis infection: recommendation statement. Ann Fam Med. 2004 Jul-Aug;2(4):362-5. doi: 10.1370/afm.215. Erratum in: Ann Fam Med. 2004 Sep-Oct;2(5):517. PMID: 15335137; PMCID: PMC1466700. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1466700/.

 

9. Royalty-free music used for this episode: Good Vibes Alt Mix by Videvo, downloaded on May 06, 2022 from https://www.videvo.net/royalty-free-music-track/good-vibes-alt-mix/1017292/

 

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