NEONATAL SOCIETY ABSTRACTS
Are we missing something? Detection of infants at risk of congenital syphilis, their treatment and follow-up
Presented at the Neonatal Society 2005 Summer Meeting (programme).
Sothinathan U1, Reeves I2, Tenant-Flowers M2, Fowler A3, Zuckerman M3, Hannam S1
1 Department of Child Health, King’s College Hospital, London, UK
2 Department of Sexual Health, King’s College Hospital, London, UK
3 Department of Virology, King’s College Hospital, London, UK
Background: National guidelines state that infants born to mothers with evidence of previous or current treponemal infection at routine antenatal screening should be tested at birth. If treponemal IgM is negative, evidence of declining treponemal IgG titres at three, six and twelve months should be obtained before discharge.
Aims: Following two cases of congenital syphilis in this institution we decided to; estimate the seroprevelance of treponemal infection in women booking in the antenatal clinic, assess the adequacy of the antibiotic therapy of pregnant women with suspected syphilis and check the follow-up of their infants.
Methods: There is no specific test for syphilis. Treponemal serological assays detect antibody to syphilis, bejel, yaws or pinta. We use an ELISA that detects total treponemal antibody (IgG and IgM). If positive, rapid plasma reagin (RPR) and Treponema Pallidum Particle Agglutination (TPPA) are carried out. All maternal booking bloods from March 2000 to February 2002 were reviewed for positive treponemal serology. Cases of maternal syphilis were then identified by reviewing case notes and adequacy of treatment to prevent vertical transmission of syphilis assessed according to published guidelines (1). All women with positive treponemal serology, detected for the first time on antenatal screening should be treated. Women with primary, secondary or early latent syphilis were defined as being at high risk of vertically transmitting syphilis. All samples obtained from infants born in the study period at this hospital, where ‘syphilis serology’ had been requested, were assessed. Those with positive serology had their case notes reviewed.
Results: 8517 women were screened. Seventy had positive treponemal serology (seroprevalence= 0.8%, 95% confidence interval 0.7 to 1.1), 43 of whom were diagnosed for the first time during pregnancy as a result of the screening programme. Of these, 23 received inadequate treatment to prevent vertical transmission. A further 5 women, where syphilis had been diagnosed previously, had received inadequate treatment. Five women probably had yaws and 4 were coinfected with HIV. Four women had early latent syphilis, of whom one had been inadequately treated and went on to have the pregnancy terminated. Of the 63 infants born at this institution, 29/63 (46%) were screened at birth, 9/63 (14%) at 3 months, 5/63 (8%) at 6 months and 1/63 (1.5%) at one year. Seven of the 27 infants at low risk of vertical transmission, whose mothers had received suboptimal therapy, were treated at birth.
Conclusion: To prevent an increase in the incidence of congenital syphilis, the problem of inadequate screening at birth and incomplete follow-up of at risk infants need to be addressed. Treatment of infants who are at low risk of vertical transmission should also be considered if maternal therapy has been inadequate.
1. UK national guidelines on the management of early syphilis. www.bashh.org