Cost-Effectiveness of Rapid Syphilis Screening in Prenatal HIV Testing Programs in Haiti

Background: New rapid syphilis tests permit simple and immediate diagnosis and treatment at a single clinic visit. We compared the cost-effectiveness, projected health outcomes, and annual cost of screening pregnant women using a rapid syphilis test as part of scaled-up prenatal testing to prevent mother-to-child HIV transmission in Haiti. Methods and Findings: A decision analytic model simulated health outcomes and costs separately for pregnant women in rural and urban areas. We compared syphilis syndromic surveillance (rural standard of care), rapid plasma reagin test with results and treatment at 1-wk follow-up (urban standard of care), and a new rapid test with immediate results and treatment. Test performance data were from a World Health Organization–Special Programme for Research and Training in Tropical Diseases field trial conducted at the GHESKIO Center Groupe Haitien d'Etude du Sarcome de Kaposi et des Infections Opportunistes in Port-au-Prince. Health outcomes were projected using historical data on prenatal syphilis treatment efficacy and included disability-adjusted life years (DALYs) of newborns, congenital syphilis cases, neonatal deaths, and stillbirths. Cost-effectiveness ratios are in US dollars/DALY from a societal perspective; annual costs are in US dollars from a payer perspective. Rapid testing with immediate treatment has a cost-effectiveness ratio of $6.83/DALY in rural settings and $9.95/DALY in urban settings. Results are sensitive to regional syphilis prevalence, rapid test sensitivity, and the return rate for follow-up visits. Integrating rapid syphilis testing into a scaled-up national HIV testing and prenatal care program would prevent 1,125 congenital syphilis cases and 1,223 stillbirths or neonatal deaths annually at a cost of $525,000. Conclusions: In Haiti, integrating a new rapid syphilis test into prenatal care and HIV testing would prevent congenital syphilis cases and stillbirths, and is cost-effective. A similar approach may be beneficial in other resource-poor countries that are scaling up prenatal HIV testing. Analyzing data from Haiti, Bruce Schackman and colleagues report that scale-up of prenatal HIV testing programs provides a cost-effective opportunity to prevent congenital syphilis through rapid testing. Background.: Congenital syphilis (syphilis that is passed on from a woman infected with the disease to her unborn baby) is a major preventable public health problem. Around half of all pregnancies among women infected with syphilis result in stillbirth or death of the baby shortly after birth. However, it should be possible to reduce the health burden of congenital syphilis if infections among pregnant women could be quickly and accurately diagnosed. In resource-poor countries, many syphilis infections go undiagnosed, because the tests that are normally used involve sending samples away to a laboratory for processing. This means that the diagnosis can only be confirmed, and treatment started, at the next available visit. As a result, there is a delay in starting antibiotic treatment, and some women may never receive their intended treatment at all if they cannot return for their follow-up visit. However, new tests are available that don't involve cold storage of reagents or electrical equipment, and these can be used to give an immediate result about syphilis infection even in rural or resource-poor settings. Currently, global initiatives are underway to ensure many more pregnant women are tested for HIV and to reduce the risk of HIV being passed on from a woman to her baby. These initiatives could provide an important opportunity for carrying out widespread immediate screening for syphilis during pregnancy as well. Such screening might then help reduce infant deaths substantially. Why Was This Study Done?: Field trials evaluating rapid syphilis tests have already been carried out by the World Health Organization's Special Programme for Research and Training in Tropical Diseases. One such trial, carried out in Port-au-Prince, Haiti, evaluated the success of three different rapid syphilis tests as compared to two “gold standard” tests (older tests that are generally considered reliable, but which don't give an immediate result). These researchers wanted to use data from these trials to compare costs and predicted health outcomes of including different types of syphilis screening as part of scaled-up prenatal care. Specifically, the researchers wanted to find out whether including rapid syphilis testing as part of universal prenatal care would be cost-effective and whether it would reduce the rate of stillbirths and congenital syphilis. What Did the Researchers Do and Find?: This research was based on data from the field trials previously carried out in Haiti. The data from these trials were used to create a model comparing three different strategies for screening pregnant women for syphilis infections. The three strategies were as follows: checking for the symptoms of syphilis (assumed to be the standard of care in rural areas); standard testing for antibody response to the syphilis bacterium, after which treatment can be provided at follow-up a week later (assumed to be the standard of care in urban areas); and, finally, rapid testing that gives an immediate result. For each strategy, the researchers predicted what the health outcomes would be. These outcomes are summarized in “disability-adjusted life years” (DALYs) that reflect the number of years of healthy life lost due to congenital syphilis among newborn babies, the number of stillbirths, and the number of neonatal deaths. Cost-effectiveness of each strategy was also worked out by dividing the additional costs of testing and treatment for each strategy by the number of DALYs avoided using that screening method compared to the next most expensive alternative. Under the model, urban and rural settings were looked at separately. Immediate testing was more expensive than either standard testing or checking for symptoms, but emerged as more cost-effective than standard testing in rural settings; the immediate test would cost an additional $7–$10 per disability-adjusted life year compared to the current rural or urban standard of care. The researchers predicted that if immediate syphilis testing were provided to all pregnant women in Haiti who currently have access to prenatal care, over 1,000 congenital syphilis cases would be avoided, along with over 1,000 stillbirths and neonatal deaths, at a yearly cost of $525,000. What Do These Findings Mean?: This model suggests that including rapid syphilis testing as part of current global initiatives for preventing mother-to-child transmission of HIV could substantially reduce infant deaths. The strategy is also likely to be cost-effective. Additional Information.: Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040183.