Canadian Public Health Laboratory Network Laboratory Guidelines for Congenital Syphilis and Syphilis Screening in Pregnant Women in Canada
Abstract
Despite universal access to screening for syphilis in all pregnant women in Canada, cases of congenital syphilis have been reported in recent years in areas experiencing a resurgence of infectious syphilis in heterosexual partnerships. Antenatal screening in the first trimester continues to be important and should be repeated at 28 to 32 weeks and again at delivery in women at high risk of acquiring syphilis. The diagnosis of congenital syphilis is complex and is based on a combination of maternal history and clinical and laboratory criteria in both mother and infant. Serologic tests for syphilis remain important in the diagnosis of congenital syphilis and are complicated by the passive transfer of maternal antibodies which can affect the interpretation of reactive serologic tests in the infant. All infants born to mothers with reactive syphilis tests should have nontreponemal tests (NTT) and treponemal tests (TT) performed in parallel with the mother's tests. A fourfold or higher titre in the NTT in the infant at delivery is strongly suggestive of congenital infection but the absence of a fourfold or greater NTT titre does not exclude congenital infection. IgM tests for syphilis are not currently available in Canada and are not recommended due to poor performance. Other evaluation in the newborn infant may include long bone radiographs and cerebrospinal fluid tests but all suspect cases should be managed in conjunction with sexually transmitted infection and/or pediatric experts.
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- In many Sub-Saharan African countries guidelines recommend that serological test for syphilis should be done to pregnant women at a time of first prenatal visit and additional test should be done during the third trimester in women suspected at increased risk. In most African countries syphilis screening in pregnant women is a national health policy, but few screening programs achieve universal coverage for testing, mainly due to either logistical or financial constraints [2,12,13]. Tanzania is amongst several countries that recommend single dose benzathine penicillin for the treatment of pregnant women with syphilis as a national policy. In theory, women can thus be tested and treated on the same day if on-site syphilis screening at the ANC is operational [14].
[Show abstract] [Hide abstract] ABSTRACT: Objective: The present study was conducted to assess the prevalence of syphilis and screening challenges among pregnant women coming for delivery at Dodoma Regional Hospital. Methods: A review of antenatal/ labor records for deliveries that were conducted from January to December 2010 (n=10,462) at Dodoma Regional Hospital was done to obtain the proportion of women who were not tested for syphilis. A cross-sectional study was also carried among 125 pregnant women coming for delivery at the hospital April-May 2011 to collect information on syphilis testing and on facilities where women attended for antenatal care but not tested. Questionnaires were used to obtain relevant information during face to face interviews. Interviews were also conducted with health providers (laboratory staff and heads of RCH clinics) where syphilis testing was not performed to get their views on barriers for syphilis screening. Results: Among the 10, 462 reviewed records of women presenting for delivery in 2010 at Dodoma Regional Hospital, 1120 (11%) were not tested for syphilis at the time of admission to the labour ward. Of the remaining 9,432, seventy one were positive for syphilis, giving a prevalence of 0.8%.Among the 125 interviewed women at admission to the labor ward, 43 (34%) were not screened for syphilis during pregnancy compared to only 3% who were not screened for HIV. The key challenge for syphilis screening reported by health providers was the frequent stock out of rapid syphilis screening tests (Bioline syphilis test). Conclusion and recommendations: A high proportion of pregnant women (34%) coming for delivery were not scrrened for syphilis in Dodoma. Screening for syphilis is cost-effective even when prevalence is 0.1% as recommended by the WHO, hence the health managers of respective clinics should make sure the facilities are getting syphilis testing kits in smooth manner like the HIV kits.- [Show abstract] [Hide abstract] ABSTRACT: This article aims to provide an update on the prevention of mother-to-child transmission of syphilis by drawing upon some important basic concepts and reviewing the most recent literature on the diagnosis and treatment of syphilis in pregnancy. New technologies, such as automated and point-of-care immunologic tests, are shifting some paradigms, which will certainly be further investigated in the forthcoming years. This is the time to carefully evaluate traditional as well as new strategies to prevent congenital syphilis. Adverse outcomes of mother-to-child transmission of syphilis can be prevented with antenatal screening and penicillin therapy, which proved to have an excellent cost-benefit ratio even in populations with a low prevalence of syphilis. However, syphilis epidemiology is influenced by socioeconomic and cultural factors, and major challenges are faced by poor and developing countries in which the severity of the problem is extremely alarming. On the other hand, the emergence of new technologies has raised doubts about the best algorithm to be used when proper laboratory resources are available. Conditions are quite heterogeneous across populations, and some procedures should not be generalized while there is no evidence that supports some changes and while in-depth studies about local conditions are not conducted. Official organizations need to be alert in order to avoid isolated decisions and ensure that evidence-based guidelines be used in the management of syphilis in pregnancy.
- [Show abstract] [Hide abstract] ABSTRACT: Serology has a pivotal role in the diagnosis of congenital syphilis (CS), but problems arise because of the passive transfer of IgG antibodies across the placenta.The aim of this study was to assess the diagnostic value of a comparative Western Blot (WB) method finalized to match IgG immunological profiles of mothers and their own babies at birth, in order to differentiate between passively transmitted maternal antibodies and antibodies synthesized by the infants against Treponema pallidum.Thirty infants born to mothers with unknown or inadequate treatment for syphilis entered in a retrospective study, conducted at St. Orsola-Malpighi Hospital, Bologna, Italy.All the infants underwent clinical, instrumental and laboratory examinations, including IgM WB testing.For the retrospective study, an IgG WB assay was performed by blotting T. pallidum antigens onto nitrocellulose sheets and incubating the strips with mother/child pairs' serum specimens.CS was diagnosed in 11 out of the 30 enrolled infants: 9/11 cases received the definitive diagnosis within the first week of life, whereas the remaining two were diagnosed only later, because of increasing serological test titers.The use of the comparative IgG WB testing performed with mother/child pairs' serum specimens allowed a correct CS diagnosis in 10/11 cases. CS diagnosis was improved by a strategy combining comparative IgG WB with IgM WB results, leading to a sensitivity of 100%.The comparative IgG WB test is thus a welcome addition to the conventional laboratory methods used for CS diagnosis, allowing to identify and adequately treat infected infants, avoiding unnecessary therapy of uninfected newborns.
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