A review of diagnostic tests for congenital syphilis in newborns

Abstract

Congenital syphilis (CS) can occur when a mother is inadequately treated or not treated at all for an active Treponema pallidum infection. Symptoms of CS are often subtle and non-specific, and it is estimated that up to 60% of affected infants are asymptomatic at birth, making the diagnosis dependent on laboratory findings. Despite decades of experience with CS, problems still arise in its diagnosis because laboratory test results for children at risk for CS can be inconclusive and no single diagnostic test can be used to diagnose CS. The development of diagnostic tests such as enzyme immunoassays, immunoblotting and polymerase chain reaction (PCR) has increased the sensitivity and specificity of diagnoses, but the detection of specific IgM is currently the most sensitive serological method, and the presence of specific IgM should be considered as evidence of a congenital T. pallidum infection. Suspected cases can also be confirmed or excluded by serial post-partum tests of antibody kinetics. The authors note strongly that it is considered unethical not to treat a baby at risk of contracting CS, even without a definitive diagnosis. In this review, we describe the various microbiological methods-and their shortcomings-used in the laboratory diagnosis of CS.

Evaluation of the BioPlex 2200 Syphilis System as a First-Line Method of Reverse-Sequence Screening for Syphilis Diagnosis

“…It follows that a positive IgM result in a newborn's serum should be considered evidence of T. pallidum congenital infection (22,23). Actually, IgM WB is considered the gold standard for diagnosis of CS, considering its high sensitivity and specificity (24,25).…”

Sífilis congénita: presentación como shock séptico después del período neonatal

“…Considerando que los anticuerpos IgM maternos no cruzan la placenta, si éstos están presentes en el suero del neonato podría ser considerado como evidencia de infección congénita 43 . Se han desarrollado diversas tecnologías para la detección de anticuerpos IgM pero han mostrado una baja sensibilidad en niños asintomáticos.…”

“…El uso clínico de RPC en líquido amniótico, sangre o LCR, es un método alternativo con buena sensibilidad (78-86%) y especificidad (100%) 43 . Yamamoto y cols.…”

Serologic Response to Treatment in Syphilis

“…It is not necessary to conduct a treponemal test on a newborn's serum, however a test to detect immunoglobulin IgM can be recommended (Workowski & Berman, 2010). The detection of specific IgM is currently the most sensitive serological method, and the presence of specific IgM should be considered as evidence of a congenital T. pallidum infection (Herremans et al, 2010). In the past, a retrospective analysis of the serologic response to treatment of syphilis during pregnancy was performed.…”