It is widely believed (and, indeed, often taught within schools of public health) that for technical interventions to successfully reach those in need, or achieve universal coverage, they should fulfill a number of identifiable criteria: they should address a widespread and burdensome problem; the policy environment should be supportive; the interventions should be evidence-based1 and technically simple; and the intervention should demonstrate cost-effectiveness.
Prevention of congenital syphilis, apparently, fulfils all these criteria.
Calculations based on the global burden of disease estimates published by the World Health Organization show that the burden of syphilis in pregnant women is at least equal to the burden of mother to child transmission of HIV, and is probably higher than the burden associated with other infections amenable to intervention in pregnancy (such as provision of tetanus toxoid).2
Historical and more recent studies among women with active syphilis who have not received screening and treatment in pregnancy, show that a majority of them will suffer some kind of adverse event: a quarter of pregnancies will end in stillbirth or spontaneous abortion; over 10% will experience early neonatal death and a similar number of babies will be born with signs and symptoms of congenital infection. A further 20% of babies will be born prematurely or with low birth weight as a direct result of maternal syphilis infection–and will, therefore, be at increased risk of associated morbidities and long-term health problems.3,4
The health policy environment for congenital syphilis is generally encouraging. A review carried out among Ministries of Health in 22 countries in sub-Saharan Africa, for example, found that over three-quarter of them had national policies for syphilis screening in pregnancy.5 Policy reviews conducted for the World Health Organization have also found that a majority of countries contacted have a supportive health policy environment–one which encourages women to visit antenatal services, and then promotes syphilis screening for all.6
As far as technical feasibility and cost-effectiveness are concerned: what could be simpler or cheaper? Low cost screening tests (rapid plasma reagin testing) have been in existence for many years, and the more recent development of rapid point of care tests has made diagnosis of this treatable maternal condition feasible even in the most remote and hard to reach settings. Reviews of the cost-effectiveness of the intervention continually highlight that screening of all pregnant women and treatment of those who are positive is cost-effective in the majority of settings7–even when the prevalence is low. Moreover, penicillin (the treatment for most women) is off-patent, widely available, on the World Health Organization list of Essential Medicines, and, above all, cheap (median treatment price $0.25) and drug resistance is not a known widespread problem.
Despite all these positive attributes, however, syphilis screening during pregnancy remains the exception rather than the norm in many settings. As a result, the number of pregnant women with syphilis who experience adverse outcomes of pregnancy remains unacceptably high due to our failure to make this simple, cost-effective, and feasible intervention universally available.
WHY IS CONGENITAL SYPHILIS STILL A PROBLEM?
Syphilis is not a new or emerging infection. It has been recorded in literature (and sometimes in art) for at least 500 years, and diagnostic tests for syphilis, and its effective treatment with penicillin, have been available for many decades. Despite its long history and the apparent simplicity of its control, in many countries, the incidence of congenital syphilis remains unacceptably high, and in some countries the number of recorded cases has recently risen. Munkhuu et al8 in this issue present data from Mongolia that highlight the recent resurgence in cases of congenital syphilis in the country.
Why does syphilis continue to exert such a burden on pregnant women and their children? Munkhuu et al have hypothesized that some of the problems may lie with the organization of health services and the delivery of a screening-based intervention. Centralized laboratory services can impose high levels of inconvenience on women being tested (they have to travel to the central laboratories, and then wait for their results to be sent back), and often mean that women simply do not get tested at all.
Munkhuu et al present the results of a randomized controlled trial (RCT) which aimed to measure whether decentralized services could improve testing uptake, and, thereby, result in a reduction in the number of cases of congenital syphilis. Results were impressive: almost universal coverage of antenatal syphilis screening among women at their first antenatal visit, and a much lower number of cases of congenital syphilis in the intervention arm compared with the control arm.
The Munkhuu trial is important for a number of reasons: first, it is a high quality RCT–something of a rarity in the field of syphilis intervention studies. Second, it clearly shows that something as seemingly simple as implementing decentralized testing can have a significant impact on pregnancy outcomes. This has, of course, been noted previously, but rarely with the numbers involved in this study, or with a randomized control arm for comparison.
It is worth noting, however, that one other RCT carried out in South Africa a decade ago similarly compared on-site testing with centralized laboratory testing.9 While women who had on-site testing and were diagnosed with syphilis completed their treatment significantly earlier than syphilis-positive women in the centralized testing (control) arm, there was no difference noted in impact measurements (perinatal loss) in the 2 arms. The authors of that study concluded that, among other issues, the high quality of services (including laboratory services) in the control arm may have minimized the impact of the intervention itself.
It is important to see these 2 trials in context. The study in Mongolia used a newer point of care test than the study in South Africa–an important difference that the authors of the South African study predicted might have made a difference to their own results if better on-site tests had been available a decade ago.
Nonetheless, the South African RCT also highlights that a high quality antenatal care service (as seen in their control arm) can have a positive impact on congenital syphilis, even when laboratory services are centralized. In other words, while the rapid point of care tests are likely to improve the situation for controlling congenital syphilis, their absence should not be an excuse for not implementing syphilis screening for all pregnant women. Existing syphilis screening tests and services (including those that use centralized laboratory services) can have a positive impact on pregnancy outcomes if the quality of antenatal care is high enough.
Despite the evidence available to us, and the seemingly supportive policy environment, our failure to screen pregnant women for syphilis results in hundreds of thousands of avoidable fetal losses and neonatal deaths every year.
WHAT WE CAN WE DO TO CHANGE THIS?
Part of the problem for congenital syphilis control is that, up till now, it has been difficult to identify exactly who is responsible for achieving the goals of universal access to syphilis screening and treatment in pregnancy. Syphilis is, of course, a sexually transmitted infection (STI), but controlling vertical transmission lies outside the remit of the national STI program in most countries. Instead, screening and treatment for pregnant women remains the responsibility of the antenatal care services. A review of the health policy and systems environment for delivering antenatal syphilis screening in 14 countries noted that “the functional and budgetary relationship between the various agencies involved and the responsible agency for oversight was not easily delineated.”6 In other words, it was extremely difficult to find out who was responsible for making the program work in each of the 14 countries.
However, there is some optimism on the horizon: the World Health Organization has launched a global initiative to eliminate congenital syphilis, and progress is being made toward this goal in several regions. This initiative aims to encourage partnerships between STI control programs and other sexual and reproductive health services (including antenatal care), while also identifying who is going to be held accountable for achieving the goal of eliminating congenital syphilis.10 Moreover, previously vertical programs (such as the prevention of mother to child transmission of HIV) are now recognizing the positive aspects of integrated service provision. UNAIDS has recently included provision of syphilis screening and treatment as a priority indicator in measuring progress in prevention of mother to child transmission programs.11 These are important steps in the right direction–but more and faster progress is needed.
Health policy theorists have identified successful health policies as those which meet the criteria outlined above (a justifiable need to act to reduce a burdensome problem, an intervention which is effective and cost-effective, a supportive policy environment), and in addition have “champions” who promote and support the idea (these may, for example, be champions from the political or civil society arenas). Lack of any obvious champions has been identified as one of the reasons why control of congenital syphilis has, thus far, failed to be fully implemented in many settings.12 We can change this.
Now is the time for all of us to become “congenital syphilis champions,” and to eliminate this totally preventable disease which, shockingly, seems to be on the rise in the 21st century.
1. Irwig L, Zwarenstein M, Zwi A, et al. A flow diagram to facilitate selection of interventions and research for health care. Bulletin WHO 1998; 76:17–24.
3. Ingraham NR. The value of penicillin alone in the prevention and treatment of congenital syphilis. Acta Derm Venereol Suppl (Stockh) 1950; 31(suppl 24):60–87.
4. Watson Jones D, Changalucha J, Gumodoka B, et al. Syphilis in pregnancy in Tanzania. I. Impact of maternal syphilis on outcome of pregnancy. J Infect Dis 2002; 186:940–947.
5. Gloyd S, Chai S, Mercer M. Antenatal syphilis in sub-Saharan Africa: Missed opportunities for mortality reduction. Health Policy Plan 2001; 16:29–34.
6. Hossain M, Broutet N, Hawkes S. The elimination of congenital syphilis: A comparison of the proposed World Health Organization action plan for the elimination of congenital syphilis with existing national maternal and congenital syphilis policies. Sex Transm Dis 2007; 34:S22–S30.
7. Terris-Prestholt F, Watson-Jones D, Mugeye K, et al. Is antenatal syphilis screening still cost effective in sub-Saharan Africa? Sex Transm Infect 2003; 79:375–381.
8. Munkhuu B, Liabsuetrakul T, et al. One-stop service for antenatal syphilis screening and prevention congenital syphilis in Ulaanbaatar, Mongolia: A cluster randomized trial. Sex Transm Dis 2009; 36:714–720.
9. Myer L, Wilkinson D, Lombard C, et al. Impact of on-site testing for maternal syphilis on treatment delays, treatment rates, and perinatal mortality in rural South Africa: A randomized controlled trial. Sex Transm Infect 2003; 79:208–213.
12. Buse K, Martin-Hilber A, Widyantoro N, et al. Management of the politics of evidence-based sexual and reproductive health policy. Lancet 2006; 368:2101–2103.