2014.ISDS.Abstracts.Final.pdf


ISDS Annual Conference Proceedings 2014. This is an Open Access article distributed under the terms of the Creative Commons Attribution-
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ISDS 2014 Conference Abstracts

Identifying Congenital Syphilis Cases through a Birth 
Registry Match
Elliott Brannon*, Jessica Fridge and Jeffrey Hitt

STD/HIV Program, Office of Public Health, Louisiana Department of Health and Hospitals, New Orleans, LA, USA

Objective
To identify infants perinatally exposed to syphilis in Louisiana that 

were missed by routine surveillance activities and to ensure that all 
infants perinatally exposed to syphilis are investigated.

Introduction
In 2012, Louisiana’s case rate for congenital syphilis was 49.2 

cases per 100,000 live births, the highest in the nation and over 
six times the national average1. In Louisiana, case investigations 
for infants perinatally exposed to syphilis are initiated through two 
primary methods: SHP may receive a positive syphilis test on an 
infant or a syphilis-infected woman may be contacted and identified 
by Partner Services during pregnancy. This identification process is 
similar to perinatal HIV surveillance in Louisiana with one major 
exception: for perinatal HIV surveillance an annual birth match is 
completed. Through this match women known to be HIV-infected 
are matched to women who gave birth during the previous year. Over 
90% of perinatal HIV exposures are identified prior to this match, but 
the match ensures that Louisiana’s HIV surveillance system identifies 
all infants perinatally exposed to HIV.

Methods
A syphilis birth registry match was completed for the first time in 

Louisiana. Compared to HIV, a syphilis birth match is more complex 
due to the fact that a woman with a history of syphilis can eliminate 
perinatal transmission risk with appropriate treatment whereas 
perinatal transmission risk is always present for an HIV-infected 
woman. For 2013, all women in Louisiana’s STD database (PRISM) 
who ever had syphilis, were linked to all women in Louisiana’s 
Vital Records Birth Registry. The matching algorithm was locally 
developed and deterministic based on first name, last name, date of 
birth, and social security number of the mother. Matches that had 
already been investigated as possible congenital syphilis cases were 
removed. Matches were then divided into two groups: mothers who 
received treatment and mothers who did not receive treatment. SHP 
identified useful constraints for each group to remove unproductive 
investigations. For mothers with treatment the constraints included 
the following: treatment less than 30 days before delivery (or after 
delivery) OR Late/Unknown Latent syphilis without appropriate 
treatment.2 For mothers without treatment the constraints included the 
following: Last titer within three years AND positive treponemal test 
AND no treatment in PRISM. Each potential case was reviewed in 
PRISM and those unlikely to become cases were not investigated (for 
example, women who were falsely positive for syphilis). A similar 
match was also completed with the stillbirth registry.

Results
The birth/stillbirth match identified 18 potential cases of 

congenital syphilis. Ten of these have been investigated and eight 
of the investigations identified cases of congenital syphilis. The 
remaining eight investigations are currently underway. These cases 
will significantly increase Louisiana’s congenital syphilis case rate.

Conclusions
The birth match prompted the investigation of many infants 

exposed to syphilis perinatally. Many of these investigations turned 
out to be cases and these cases will substantially increase Louisiana’s 
congenital syphilis case rate. The birth match also identified the need 
of guidelines for the initiation of congenital syphilis investigations. 
SHP does not receive adequate resources to investigate all the potential 
cases and had to deprioritize investigations which were considered 
‘low risk’. Take for example a woman who gave birth in 2013, had 
Late Latent syphilis in 2008, was treated with one set of bicillin in 
2008, and had no rise in titer during pregnancy. If investigated, this 
would likely have been identified as a congenital syphilis case due to 
the mother’s inadequate treatment. SHP, however, did not investigate 
cases similar to this that were identified because of inadequate 
resources and the low risk of infection based on Kassowitz’s law. 
Although states may wish to conduct a similar birth match to ensure 
complete surveillance, initiation guidelines should be developed to 
prioritize potential cases that are productive in identifying health care 
systems issues.

Keywords
Congenital Syphilis; Birth Match; Registry Linkage

References

1. Centers for disease control and prevention. 2012 Sexually Transmitted
Diseases Surveillance. Available at http://www.cdc.gov/sTD/stats12/
default.htm. Retrieved July 15, 2014.

2. Centers for disease control and prevention. Congenital syphilis case
definition. Available at http://wwwn.cdc.gov/NNDSS/. Retrieved July 
15, 2014.

*Elliott Brannon
E-mail: elliott.brannon@la.gov    

Online Journal of Public Health Informatics * ISSN 1947-2579 * http://ojphi.org * (1):e110, 201