Episode Details

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 Co