Note to myself: In addition to today’s post, please review Links To And Excerpts From Diagnostic tests for syphilis – New Tests and new algorithms
Posted on September 6, 2020 by Tom Wade MD
This podcast covers congenital syphilis, including epidemiology, pathophysiology, impacts on mothers and infants, prenatal screening, bloodwork and follow-up for infants exposed in utero. This podcast was developed by Stephanie Unrau, a third year medical student at the University of Alberta with Dr. Joan Robinson, a pediatric infectious disease specialist at the Stollery Children’s hospital in Edmonton, Alberta.
Here are excerpts from the Script:
PODCAST 5 TAKE-HOME POINTS:
We’d like to give you the following five take-home points so you can do an awesome job
identifying and managing congenital syphilis in the future:
1. If you see a baby with chronic snuffles, unexplained hepatosplenomegaly, or unusual rashes (especially ones that look like ringworm or involve the palms or soles) think of congenital syphilis.
2. All pregnant women are screened for syphilis in Alberta as part of their routine prenatal care. If they have infectious syphilis (primary, secondary or early latent)
they must be treated as soon as possible in order to prevent adverse fetal events including spontaneous abortion/fetal demise, neurosyphilis, sensorineural deafness, osteochondritis and perichondritis, all potentially leading to lifelong sequelae.
3. Screening is performed in Alberta with the EIA treponemal test, and if it is positive then this result is confirmed on the same sample with a second treponemal test, TPPA. The nontreponemal RPR test is preformed to assess disease activity and monitor response to treatment. Public Health then receives these results, performs
contact tracing, and tries to ensure that all appropriate treatment and follow-up are arranged.
4. If a woman had infectious syphilis during pregnancy, the infant will require clinical and serological follow up. If the mother was treated 4 weeks before delivery and had
an associated 4-fold drop in her titres with no reinfection by delivery, and the investigations involving the infant are negative, the infant does not require immediate treatment. If these exact conditions are not met, then the infant needs treatment as well as investigations including CBCd, and CSF analysis, long-bone x-rays, and audiological and ophthalmological assessments.
5. If there is any concern that the baby has untreated congenital syphilis, we will treat with IV penicillin for 10 days and continue our clinical observation and monitoring
until we are sure that the infant has been adequately treated.
[Screening Prenatally For Syphilis]
Screening for syphilis in all expectant mothers at the first prenatal appointment is recommended worldwide, ideally in the first trimester. This is done as part of routine prenatal bloodwork1. The mother is given a requisition for this and other prenatal bloodwork.
In Alberta, an Enzyme Immmuno-Assay (EIA) treponemal test is used for screening. If it is positive, the same sample is then tested with another treponemal test, T.Pallidium Particle Agglutination Assay (TPPA) to confirm the results.
A non-treponemal test, Rapid Plasma Reagin (RPR) is also run if the EIA is positive.
If EIA and TPPA are both positive, a syphilis infection is assumed to be present although they can remain positive for life even after an infection has been treated.
If the mother comes from a resource poor country, there is a small chance that she has a nonvenereal treponemal disease such as Yaws, Pinta, and Bejel instead of syphilis1. However,
we cannot differentiate these from syphilis and do not want to miss the chance to prevent congenital syphilis so always assume that the mother has syphilis.
RPR is a quantitative test that allows the physician to monitor disease activity and response to treatment. A higher RPR indicates that there is a more active syphilis infection. The RPR result findings along with history, physical exam, and epidemiological findings are all needed to determine the stage of syphilis infection.
At the time of a positive EIA and TPPA test result in Alberta, Public Health notifies the patient and makes every effort to conduct partner notification and treatment.
[For details on the treatment of syphilis in pregnancy see the show notes.]