Congenital syphilis surveillance

Congenital syphilis (CS) is mainly a consequence of the lack of antenatal care and control of sexually transmitted infections.The bedrock of the prevention of CS is syphilis diagnosis by serological screening during pregnancy.Current Italian guidelines suggest that all the pregnant women should be tested in the first trimester. Due to the frequently absence of specific signs of infection at birth, laboratory tests are often the only method for a correct CS diagnosis. The aim of this study was to evaluate the usefulness of Treponema pallidum IgM Western Blot (WB) and Polymerase Chain Reaction (PCR) on cerebrospinal fluid (CSF) as an aid in the diagnosis of CS during a prospective surveillance study carried out at St. Orsola Hospital in Bologna, Italy, from November 2000 through June 2010. All pregnant women during pregnancy and at delivery were screened for syphilis by ARCHITECT® Syphilis TP, Abbott. Positive samples were further analysed by Treponema Pallidum Hemagglutination Test (TPHA) and Rapid Plasma Reagin (RPR) tests, Radim.An in-house Western Blot (WB) was also performed. Infants born to syphilis seropositive mothers were enrolled in a prospective follow up. At birth, tests were performed (including IgM WB). Infants with positive RPR tests at birth born to mothers not adequately treated received also a long bone radiograph as well as a complete CSF analysis, including Veneral Disease Research Laboratori (VDRL) (Siemens Healthcare Diagnostics) and PCR testing. All seroreactive infants received careful follow up examinations and serological testing at 0, 3, 6, 9, 12 months or until the tests became negative. In this study, positive syphilis serology was noted in 151 pregnant women delivering in our hospital. Fifteen women had never been adequately treated, and 9 out 15 gave birth to infected newborns.All these 9 infants had positive IgM WB results on serum samples. Two babies had characteristic long bone lesions at X-ray examination and 3 were born preterm. These observations confirmed that antenatal syphilis screening facilitates treatment during pregnancy and offsets vertical transmission; moreover, the use of IgM WB and careful CSF examination allowed the identification and treatment of high risk newborns.