The impact of antenatal syphilis point of care testing on pregnancy outcomes: A systematic review

Background

Mother-to-child transmission of syphilis remains a leading cause of neonatal death and stillbirth, disproportionally affecting women in low-resource settings where syphilis prevalence rates are high and testing rates low. Recently developed syphilis point-of-care tests (POCTs) are promising alternatives to conventional laboratory screening in low-resource settings as they do not require a laboratory setting, intensive technical training and yield results in 10–15 minutes thereby enabling both diagnosis and treatment in a single visit. Aim of this review was to provide clarity on the benefits of different POCTs and assess whether the implementation of syphilis POCTs is associated with decreased numbers of syphilis-related adverse pregnancy outcomes.

Methods

Following the PRISMA guidelines, three electronic databases (PubMed, Medline (Ovid), Cochrane) were systematically searched for intervention studies and cost-effectiveness analyses investigating the association between antenatal syphilis POCT and pregnancy outcomes such as congenital syphilis, low birth weight, prematurity, miscarriage, stillbirth as well as perinatal, fetal or infant death.

Results

Nine out of 278 initially identified articles were included, consisting of two clinical studies and seven modelling studies. Studies compared the effect on pregnancy outcomes of treponemal POCT, non-treponemal POCT and dual POCT to laboratory screening and no screening program. Based on the clinical studies, significantly higher testing and treatment rates, as well as a significant reduction (93%) in adverse pregnancy outcomes was reported for treponemal POCT compared to laboratory screening. Compared to no screening and laboratory screening, modelling studies assumed higher treatment rates for POCT and predicted the most prevented adverse pregnancy outcomes for treponemal POCT, followed by a dual treponemal and non-treponemal POCT strategy.

Conclusion

Implementation of treponemal POCT in low-resource settings increases syphilis testing and treatment rates and prevents the most syphilis-related adverse pregnancy outcomes compared to no screening, laboratory screening, non-treponemal POCT and dual POCT. Regarding the benefits of dual POCT, more research is needed. Overall, this review provides evidence on the contribution of treponemal POCT to healthier pregnancies and contributes greater clarity on the impact of diverse diagnostic methods available for the detection of syphilis.

Finding a needle in the haystack: the costs and cost-effectiveness of syphilis diagnosis and treatment during pregnancy to prevent congenital syphilis in Kalomo District of Zambia

BACKGROUND

In March 2012, The Elizabeth Glaser Pediatric AIDS Foundation trained maternal and child health workers in Southern Province of Zambia to use a new rapid syphilis test (RST) during routine antenatal care. A recent study by Bonawitz et al. (2014) evaluated the impact of this roll out in Kalomo District. This paper estimates the costs and cost-effectiveness from the provider's perspective under the actual conditions observed during the first year of the RST roll out.

METHODS

Information on materials used and costs were extracted from program records. A decision-analytic model was used to evaluate the costs (2012 USD) and cost-effectiveness. Basic parameters needed for the model were based on the results from the evaluation study.

RESULTS

During the evaluation study, 62% of patients received a RST, and 2.8% of patients tested were positive (and 10.4% of these were treated). Even with very high RST sensitivity and specificity (98%), true prevalence of active syphilis would be substantially less (estimated at <0.7%). For 1,000 new ANC patients, costs of screening and treatment were estimated at $2,136, and the cost per avoided disability-adjusted-life year lost (DALY) was estimated at $628. Costs change little if all positives are treated (because prevalence is low and treatment costs are small), but the cost-per-DALY avoided falls to just $66. With full adherence to guidelines, costs increase to $3,174 per 1,000 patients and the cost-per-DALY avoided falls to $60.

CONCLUSIONS

Screening for syphilis is only useful for reducing adverse birth outcomes if patients testing positive are actually treated. Even with very low prevalence of syphilis (a needle in the haystack), cost effectiveness improves dramatically if those found positive are treated; additional treatment costs little but DALYs avoided are substantial. Without treatment, the needle is essentially found and thrown back into the haystack.

Internet-based site-specific interventions for syphilis prevention among gay and bisexual men

Recent increases in syphilis in gay men in urban areas in the US and Europe have been associated with men meeting new sex partners on the Internet in chat-rooms and at websites that facilitate partner meeting. In response to the syphilis epidemic in San Francisco, the San Francisco Department of Public Health partnered with a community-based organization, Internet Sexuality Information Services, Inc., to develop, implement and evaluate a broad range of innovative Internet-based prevention interventions including the creation of a website, individual online outreach, banner advertisements, chats, an educational site, message boards, warnings and an online syphilis testing program. This paper documents the varied success of these interventions with process measures and calls for greater emphasis on impact measures in the evaluation of these types of intervention.

Comparative evaluation of 15 serological assays for the detection of syphilis infection

Fifteen commercial syphilis kits were assessed against the same moderately sized specimen panel that included 114 serum and plasma specimens from syphilis cases and 249 specimens from unselected blood donors. The 114 specimens from syphilis cases comprised 40 from cases of primary syphilis, 43 from cases of secondary syphilis, 19 from cases of early latent syphilis, and 12 from cases of late latent syphilis. Of the 15 kits, ten were enzyme immunoassays, four were Treponema pallidum haemagglutination assays, and one was a T. pallidum particle agglutination assay. Thirteen of the 15 kits gave final specificities of 100%; the other two kits were repeatedly reactive with one to two specimens. Initial sensitivities ranged from 93.9 to 99.1%. Most variation between kits was observed in results for the groups with untreated primary and treated late latent disease, although the differences were not statistically significant. The comparative data on kit performance derived from this study is useful for examining syphilis testing guidelines and for making informed purchasing decisions.

Onsite Rapid Antenatal Syphilis Screening With an Immunochromatographic Strip Improves Case Detection and Treatment in Rural South African Clinics

OBJECTIVES

Congenital syphilis is a significant cause of adverse pregnancy outcomes. In South Africa, rural clinics perform antenatal screening offsite, but unreliable transport and poor client follow up impede effective treatment. We compared 3 syphilis screening strategies at rural clinics: on-site rapid plasma reagin (RPR), on-site treponemal immunochromatographic strip (ICS) test, and the standard practice offsite RPR with Treponema pallidum hemagglutination assay (RPR/TPHA).

METHODS

Eight rural clinics performed the on-site RPR and ICS tests and provided immediate treatment. Results were compared with RPR/TPHA at a reference laboratory. Chart reviews at 8 standard practice clinics established diagnosis and treatment rates for offsite RPR/TPHA.

FINDINGS

Seventy-nine (6.3%) of 1,250 women screened on-site had active syphilis according to the reference laboratory. The on-site ICS resulted in the highest percentage of pregnant women correctly diagnosed and treated for syphilis (89.4% ICS, 63.9% on-site RPR, 60.8% offsite RPR/TPHA). The on-site RPR had low sensitivity (71.4% for high-titer syphilis). The offsite approach suffered from poor client return rates. One percent of women screened with the ICS may have received penicillin unnecessarily. There were no adverse treatment outcomes.

CONCLUSIONS

The on-site ICS test can reduce syphilis-related adverse outcomes of pregnancy through accurate diagnosis and immediate treatment of pregnant women with syphilis.

Cost-Effectiveness of On-Site Antenatal Screening to Prevent Congenital Syphilis in Rural Eastern Cape Province, Republic of South Africa

OBJECTIVES

On-site screening and same-day treatment of maternal syphilis in underresourced settings can avert greater numbers of congenital syphilis cases, but health outcomes and associated costs must be evaluated jointly.

METHODS

We used decision analysis to estimate the incremental cost-effectiveness of two on-site antenatal syphilis screening strategies to avert congenital infections-qualitative RPR (on-site RPR) and treponemal immunochromatographic strip assay (on-site ICS)-compared to the current practice (off-site RPR/TPHA).

FINDINGS

With antenatal active syphilis prevalence of 6.3%, the incremental cost-effectiveness of on-site ICS in averting congenital infections was estimated to be USD104, averting 82% of cases expected in absence of a program. The incremental cost-effectiveness of off-site RPR/TPHA was USD82 but would avert only 55% of congenital syphilis cases. On-site RPR was dominated by the other screening strategies.

CONCLUSIONS

In settings of high maternal syphilis prevalence, on-site antenatal screening with ICS is a cost-effective approach to reduce the incidence of congenital syphilis.

Screening for syphilis in pregnancy: which is the proper method?

BACKGROUND

Consequences of syphilis in mother, pregnancy, fetus and child are considerable, but preventable. Serological screening must be offered at the first prenatal visit. Presently, the diagnosis of syphilis is dependent mainly on serological tests. The most widely used screening tests for syphilis are the VDRL and the rapid plasma reagin (RPR) and for confirmation the fluorescent treponemal antibody (FTA) and the treponema pallidum hemagglutination (TPHA) tests.

METHOD

The four alternative nodes for diagnosis of can be a) VDRL + FTA, b) VDRL + TPHA, c) RPR + FTA and d) RPR + TPHA. Here the author reports an evaluation of cost utility of those tests in obstetrical practice. According to this study, it can be shown that the cost per accurate diagnosis for VDRL + TPHA is the least expensive choice and for RPR + FTA is the most expensive choice.

CONCLUSION

Therefore, this alternative is the best method for serological diagnosis of syphilis, based on medical laboratory economics principles.

Modelling the cost-effectiveness of introducing rapid syphilis tests into an antenatal syphilis screening programme in Mwanza, Tanzania

OBJECTIVES

A study found screening (with rapid plasma reagin (RPR)) pregnant women for maternal syphilis was cost-effective in Mwanza, Tanzania. Recently, four rapid point-of-care (POC) syphilis tests were evaluated in Mwanza, and found to have reasonable sensitivity/specificity. This analysis estimates the relative cost-effectiveness of using these POC tests in the Mwanza syphilis screening intervention.

METHODS

Empirical cost and epidemiological data were used to model the potential benefit of using POC tests instead of RPR. Reductions in costs relating to training, supplies, and equipment were estimated, and any changes in impact due to test sensitivity were included. Additional modelling explored how the results vary with prevalence of past infection, misclassified RPR results, and if not all women return for treatment.

RESULTS

The cost-effectiveness of using POC tests is mainly dependent on their cost and sensitivity for high titre active syphilis (HTAS). Savings due to reductions in training and equipment are small. Current POC tests may save more disability-adjusted life years (DALYs) than the RPR test in Mwanza, but the test cost needs to be <0.63 US dollars to be as cost-effective as RPR. However, the cost-effectiveness of the RPR test worsens by 15% if its HTAS sensitivity had been 75% instead of 86%, and by 25-65% if 20-40% of women had not returned for treatment. In such settings, POC tests could improve cost-effectiveness. Lastly, the cost-effectiveness of POC tests is affected little by the prevalence of syphilis, false RPR-positives, and past infections.

DISCUSSION

Although the price of most POC tests needs to be reduced to make them as cost-effective as RPR, their simplicity and limited requirements for electricity/equipment suggest their use could improve the coverage of antenatal syphilis screening in developing countries.

[Syphilis test proposed within the context of a programme to reduce mother/child HIV transmission: example of the Wassakara Health Care Center in Abidjan]

During the program MTCT+ set up in Abidjan by the national authorities with the assistance of the FSTI and FGSK, free screening and treatment of the syphilis infection were proposed to pregnant women. One test of agglutination on blades VDRL (Carbon Antigen Biotec the U.K.) and one TPHA test on plates for the positive VDRL (TPHA Nosticon Biomérieux F) were performed. Over the period from June 1999 to December 2001, 4 320 samples were taken. The laboratory observed 84 positive tests VDRL and 59 confirmed by TPHA, that is to say a syphilis seroprevalence (TPHA) of 1.4%. In addition 391 results were not available for various reasons (errors of numbering, haemolysed blood, absence of reagents, etc.) ie. 9.0%. Among the 59 positive women (TPHA), 30 came back for their result and 23 women were correctly treated (3 or 4 penicillin delay injections). In addition 7 partners received a complete treatment and 8 incomplete treatment. The cost of each detected and treated case rose approximately to 150 Euros, which is relatively low except in time/ staff and indirect costs for women. This study confirmed that all the activities of SMI must be integrated to have an efficient PTME programme. The biological assessment must be accessible as a whole, to minimize the additional costs and transportations. A training of all the personnel in 2002 helped to improve in an important way the results of the intervention in the center.

Syphilis serology testing: a comparative study of Abbot Determine, Rapid Plasma Reagin (RPR) card test and Venereal Disease Research Laboratory (VDRL) methods

Blood from 2100 women attending the antenatal clinic of the Port Moresby General Hospital (PMGH) and the 9 Mile urban clinic of Port Moresby was tested for syphili using the laboratory-based Venereal Disease Research Laboratory (VDRL) syphilis serology test and two clinic-based syphilis tests, Abbot Determine and Abbot Syfacard-RR (Rapid Plasma Reagin (RPR) card test). The Abbot Determine and the Syfacard-R tests were compared with the VDRL test, the gold standard in this study. The validation test results of Determine versus VDRL were as follows: sensitivity 92.0%; specificity 94.6%; the predictive value of a positive test 42.6%; and the predictive value of a negative test 99.6%. The validation tests for RPR versus VDRL were as follows: sensitivity 56.3% specificity 96.5%; predictive value of a positive test 41.2%; and the predictive value of a negative test 98.1%. The RPR test costs 3.5 kina (about one US dollar) a test, the VDRL less than 1 kina a test whilst the Determine test kit costs about 5 kina a test. When laboratory time, salaries and other supplies are costed the Determine test is expected to cost relatively much less. Our recommendation is that the Determine test be made available in areas of the country where VDRL is unavailable or where logistics do not allow for test results to be available early enough to make a difference to the care of th pregnant woman and her fetus.

Examining the direct costs and effectiveness of syphilis detection by selective screening and partner notification

Selective screening and partner notification are two principal means of preventing and controlling syphilis in the United States, yet few studies have been undertaken to compare and evaluate the cost or effectiveness of detecting syphilis using either strategy. The objective of this paper is to assess from the perspective of a health department the cost-effectiveness of selective screening compared with the strategy of partner notification in the detection of early syphilis in Houston, Texas, in 1994 and 1995. The cost-effectiveness analysis was performed using the recurring direct costs associated with detecting syphilis by both strategies. The middle estimates for the total direct costs associated with selective screening and partner notification were $579,101 and $229,529, respectively, for the 1466 and the 567 cases of early syphilis detected. On a cost per case basis, selective screening was more cost-effective than partner notification in the detection of primary, secondary and maternal syphilis cases. However, when consideration was given to prophylactic treatment, partner notification was more cost-effective in the detection of all early stage disease. Our findings suggest that the relative benefit of partner notification over selective screening depends on prophylactic treatment and an increase in worker productivity.

[Serologic screening for neurosyphilis]

BACKGROUND

Syphilis serology is analysed in all patients admitted as in-patients to the Department of Neurology in Tromsø. In this study we examined the utility of performing routine laboratory testing for syphilis in neurological patients.

MATERIAL AND METHODS

We registered all in-patients in the Department of Neurology with a confirmed diagnosis of syphilis during a ten-year period (1990-1999). Additionally, we calculated the cost of performing laboratory tests of all hospitalised patients in this period.

RESULTS

From a total of 8,637 patients, we identified five patients with syphilis, one of them with neurosyphilis. This patient had impaired cognitive functions at the time of admittance and a broad spectrum of neurological deficits suggesting a serious neurological disease. A positive syphilis serology confirmed the diagnosis and treatment was initiated. The mean cost for Treponema pallidum serological screening in neurological patients during 10 years was calculated to be about NOK 17,000 per year.

INTERPRETATION

Tertiary syphilis is a serious disease with symptoms often mimicking other diseases. Although the laboratory tests for syphilis have been performed in every in-patient admitted to the neurological ward, a speedier diagnosis of neurosyphilis could not be detected in any patient in a ten-year hospital material. Routine serological examination for syphilis in neurological patients is therefore not recommended in this geographical area.

Antenatal syphilis in sub-Saharan Africa: missed opportunities for mortality reduction

PURPOSE

Between 4-15% of pregnant women are believed to be infected with syphilis in sub-Saharan Africa. Active infection with syphilis in pregnant women results in foetal or infant death or disability for 50-80% of affected pregnancies, and is a major cause of adult morbidity as well. Antenatal syphilis screening is cheap and effective; however, it is often poorly implemented in countries with high syphilis risk. This study sought to estimate the missed opportunities for antenatal syphilis screening in sub-Saharan Africa.

METHODS

Survey data were collected from 22 ministries of health in sub-Saharan Africa, complemented by data from published sources and key informants. Informants described their country's policies and experience with antenatal syphilis screening and estimated their national syphilis screening rates.

FINDINGS

Seventy-three percent of women are reported by WHO to receive antenatal care in the study countries. Of women in antenatal care, 38% were estimated by survey respondents to be screened for syphilis. Costs and the organization of services were the principal reported obstacles to screening. With syphilis seroprevalence estimated at 8.3%, approximately 1 640 000 pregnant women with syphilis are undetected annually, including 1 030 000 women who attend antenatal care.

DISCUSSION

Syphilis testing and treatment is a cost-effective intervention that deserves much greater attention, particularly in sub-Saharan Africa and other countries where syphilis infection is high.

Effectiveness and cost-benefit of enhancements to a syphilis screening and treatment program at a county jail

BACKGROUND

High rates of syphilis are found in inmates of county jails. Treatment of this infected transient population necessitated the development of a rapid protocol.

GOAL

To evaluate a rapid screening and treatment protocol for syphilis in a county jail.

STUDY DESIGN

Over a 2-year period 18,442 inmates were screened for syphilis with a nontreponemal test and record search for treatment history. Confirmatory test results were reviewed following treatment. Cost was defined as deflated marginal outlays. Benefit was calculated as the discounted expected cost of treatment of congenital, late, and neurosyphilis.

RESULTS

The sensitivity, specificity, and positive predictive value of the protocol were 99.6%, 80.8%, and 79.3%, respectively. Of 257 confirmed cases, 183 were offered treatment in jail. The percentage of short-term inmates treated increased following implementation. The cost-benefit ratio was 9.14:1.

CONCLUSIONS

The protocol was highly effective in patient identification and treatment delivery, and cost-effective as well.

[Positive results from serologic screening for syphilis in pregnancy in the Amsterdam region, 1991-1995]

OBJECTIVE

To evaluate the results of screening of pregnant women for syphilis in the region of Amsterdam, the Netherlands.

DESIGN

Descriptive study and cost-benefit analysis.

METHODS

In the period 1991-1995, physicians and midwives from the Amsterdam region sent serum samples of pregnant women to the Regional Public Health Laboratory of the Municipal Health Service (GG & GD) to be screened for syphilis. All physicians who had sent in specimens with a positive result of the Treponema pallidum haemagglutination assay (TPHA) and a confirming test result were asked, in the year of the screening, by telephone or in writing, what diagnosis they had made in the woman in question. Collection of these data was handled by the social nursing staffs of the outpatient clinics for sexually transmitted diseases in Amsterdam. The costs of laboratory tests and follow-up of the children were compared with the positive effects of special treatment and education avoided by antibiotic treatment.

RESULTS

54,344 serum samples were sent in. In the city of Amsterdam the coverage was 87.4%. In 81 women (0.15%) all the serological tests for syphilis were positive. From this group, 37 women had already been treated and 24 women were treated as a result of this screening programme (most of them had a foreign nationality), 10 for early syphilis and 14 for syphilis of unknown duration, preventing the birth of an estimated five to six children with congenital syphilis. The cost-benefit ratio was 1:15.

CONCLUSION

Continuation of screening for syphilis during pregnancy in the Amsterdam region remains useful.

Accuracy of on-site screening for syphilis among women attending a rural mobile antenatal clinic

OBJECTIVE

To determine the accuracy and cost of on-site antenatal clinic syphilis screening, compared with laboratory-based screening.

SETTING

Mobile primary care clinic providing antenatal care in remote rural areas in Hlabisa health district; the prevalence of syphilis is 8.5%.

METHODS

528 consecutive women screened for syphilis by a rapid plasma reagin (RPR) test on plasma derived from whole blood by gravity. A battery-powered, solar-charging rotator mixed antigen with plasma. The RPR test was repeated on serum in a reference laboratory for comparison.

RESULTS

The on-site test was highly sensitive (86.7%; 95% confidence interval (CI) 72.5-94.5%) and highly specific (88.2%; 95% CI 84.9-90.9). The positive predictive value (40.6%; 95% CI 30.9-51.1) was low owing to a large number of samples reported as 'slightly positive' on site being reported as 'negative' in the laboratory. There were very few false-negative results on site (negative predictive value 98.6%; 95% CI 96.8-99.4). The cost of the rotator is R3 521 and reagent costs are 81c per woman screened.

CONCLUSIONS

On-site RPR screening for syphilis is highly accurate, cheap and easy to do. This strategy may reduce perinatal mortality by increasing the proportion of pregnant women with syphilis who are adequately treated.

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND

This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T-lymphotropic virus via the transfusion of seronegative, infectious window-period blood.

STUDY DESIGN AND METHODS

Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window-period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window-period donations is the number of post-screening HIV-infectious donations removed by STS.

RESULTS

Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window-period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million.

CONCLUSION

STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.

Unreliability of current screening tests for syphilis in chronic psychiatric patients

OBJECTIVE

This study examined whether psychiatrists perform adequate diagnostic screening for syphilis in patients with chronic mental illness.

METHOD

Two hundred patients with chronic mental illness underwent testing for syphilis with the commonly used RPR test and the microhemagglutination assay for Treponema pallidum (MHA-TP). Sensitivities of the two tests were compared.

RESULTS

A substantial number of patients with negative results on RPR tests had reactive MHA-TPs and would have not been identified as having had syphilis with the use of RPR testing alone.

CONCLUSIONS

Nontreponemal tests such as the RPR test are less likely than treponemal tests to detect syphilis appropriately in chronically mentally ill patients, and specific treponemal tests such as the MHA-TP should be considered.

[Cost-effectiveness of syphilis screening in a clinical for general psychiatry]

The most important clinical picture of syphilis for psychiatry is that of progressive paralysis. It is an organic psychosis with varying psychopathology. Therefore, nearly all patients in psychiatric departments undergo lues screening (TPHA) on admission. A cost-benefit analysis is presented. In the examination period from 1 January 1983 to 30 September 1988, in all 8915 patients were newly admitted to the department of general psychiatry at the University Hospital of Essen: 98 of these patients were TPHA-positive, and 6 patients had to be treated with antibiotics. One patient had neurolues. It seems therefore, that lues screening in a department of general psychiatry is performed for traditional reasons at high cost but with minimal benefit. The 6 patients who underwent a specific therapy were analysed; a catalogue of indication criteria for TPHA screening was elaborated and is presented.

Sentinel surveillance for HIV-1 among pregnant women in a developing country: 3 years' experience and comparison with a population serosurvey

OBJECTIVES

To establish unlinked, anonymous sentinel surveillance for HIV-1 among pregnant women attending an antenatal clinic, to determine age-specific seroprevalences, to monitor trends and to compare seroprevalence with that detected by a population serosurvey. To establish the sustainability and costs of surveillance.

DESIGN

Sentinel surveillance for HIV through serial collection of unlinked, anonymous seroprevalence data from antenatal care; comparison of sentinel data with those from a population serosurvey; financial and general audit of the sentinel surveillance.

SETTING

A community antenatal clinic in a large urban centre, Mwanza Municipality, Tanzania, eastern Africa, between October 1988 and September 1991.

PATIENTS

Pregnant women attending for antenatal care.

MAIN OUTCOME MEASURE

Age-specific HIV-1 seroprevalences, trends over time, difference from age-specific population seroprevalences, sustainability and costs.

RESULTS

Overall HIV-1 seroprevalence was 11.5% (95% confidence interval, 10.5-12.4); differences in age-specific prevalences were not significant. There was no clear evidence of change in seroprevalence over the study period in any age group, although there was some indication of a rise in some age groups in 1988-1989. Sentinel surveillance among pregnant women may have significantly underestimated population HIV-1 seroprevalence for women under the age of 35 years. HIV-1 surveillance proved feasible and sustainable. Additional recurrent costs were US$1.7 per specimen for unlinked anonymous testing and US$0.57 per woman for syphilis screening.

CONCLUSIONS

HIV-1 seroprevalence did not change significantly over 3 years, probably implying a substantial incidence of HIV-1 infection. In this setting seroprevalence in pregnant women may have underestimated population seroprevalence in women aged under 35 years. With modest inputs and good organization unlinked anonymous HIV-1 sentinel surveillance of pregnant women can be introduced and sustained in an African setting. This may usefully be carried out in conjunction with syphilis screening.

[Routine screening for syphilis in neurology is not useful]

In a retrospective study the results of the screening for syphilis in one of the neurological wards of the Academic Medical Centre in Amsterdam were analysed. The Venereal Disease Research Laboratory test (VDRL) and the Treponema Pallidum Haemagglutination Assay (TPHA) in serum were used for screening. The data for analysis were obtained via the hospital computer data base and via the medical files of the department of neurology. During the 5-year study period (1986-1990) 2378 adult patients were admitted and 1247 (52.4%) of them were screened. In seven (0.56%) patients both tests were positive. Three of them had been treated for syphilis in the past and showed no symptoms of active syphilis. Four (0.32%) patients suffered from active neurosyphilis. In three of these four patients syphilis was suspected on admission and confirmed by the tests. In one patient the diagnosis of syphilis was not considered. The positive test results became available shortly before she died of pneumonia and were without consequences. None of the 32 (2.6%) patients with a positive TPHA and a negative VDRL was diagnosed as having (neuro-)syphilis. Two (0.16%) patients had a false-positive VDRL. We conclude that routine serological examination for syphilis of every patient admitted to a neurological ward is not useful. We advise a limited screening of patients who belong to a group with high risk for syphilis and patients with symptoms and signs that can be caused by syphilis, such as dementia or ischaemic strokes at a relatively young age.

Syphilis screening in adolescents

Routine screening for syphilis among sexually active adolescents is recommended by the American Academy of Pediatrics, but there are few data about clinical application of these recommendations. We examined the yield of a syphilis screening program in one ambulatory adolescent medicine clinic. A rapid plasma reagin (RPR) has been recommended for all sexually active adolescents. Of 630 patients screened for syphilis by RPR, ten patients had reactive syphilis serologies and 4 had active syphilis. Of these, 2 patients had signs or symptoms consistent with primary or secondary syphilis, and 2 patients with active syphilis had clinical evidence of another sexually transmitted disease but no clinical manifestations of syphilis. Of the 10 reactive serologies, 6 represented previously treated cases or a false positive. We conclude that screening should be done for those at high risk for syphilis or those adolescents with sexually transmitted diseases.

[Economic aspects of serologic syphilis tests in routine screening in Viennese hospital facilities]

971, 786 patients in Viennese municipal hospitals were routinely screened by serological testing for syphilis between January 1980 and December 1984, leading to the detection of 28,090 cases of untreated latent infection. The annual incidence varied between 7463 and 4623 cases. Roughly one third of patients with untreated syphilis develop severe late manifestations: 10.4% show cardiovascular involvement, 6.5% get neurosyphilis and 15.8% have a gumma. The mortality rate is 85% in cardiovascular disease and 64% in neurosyphilis, whilst irreversible incapacity is the fate of the remaining 15% and 36% of these patients, respectively. Calculations on the basis of the current costs for treatment of the acute diseased and for nursing of incapacitated patients reveal that routine screening of all in- and out-patients of the Viennese municipal hospitals is completely justified from the medical and the economic point of view and should, therefore, be reinforced.

Routine hepatitis screening in adolescent pregnancies: is it cost effective?

In most obstetric centers routine serum screening for hepatitis B is not part of standard prenatal care. This study was designed to determine whether hepatitis B screening is cost effective for routine prenatal testing. In a prenatal population of 585 adolescents the cost-benefit ratio of hepatitis B screening was compared with that of routine syphilis screening. Eight positive results were detected, with a cost of $1755 per positive case. This compared favorably with the frequency and cost of detection of syphilis in the same population. Routine hepatitis B screening is recommended for consideration in similar prenatal populations.

[Is systematic syphilis serology still useful in a department of internal medicine? A one-year prospective study using a diagnostic and therapeutic decision algorithm]

During one year syphilis serology was systematically studied, using the TPHA and VDRL tests, in each of the 1,279 patients hospitalized in an Internal Medicine department. In all cases diagnosis and treatment were analyzed by means of a decision algorithm. Only 37 patients were found to have one or both serological tests positive. No evolutive syphilis was observed, and none of these positive tests was contributive to the diagnosis of another disease. Only 14 patients received a specific antibiotic treatment on the grounds that their positive test confirmed a late asymptomatic syphilis. We conclude that systematic syphilis serological tests are not useful in an Internal Medicine department, except in some patients epidemiologically at high risk of syphilis.

Hemagglutination treponemal test for syphilis

Sera from 290 hospital patients were tested to compare the sensitivity, specificity, and reproducibility of the hemagglutination treponemal test for syphilis (HATTS) with the fluorescent treponemal antibody absorption test (FTA-ABS). Complete agreement was obtained between the methods when 142 syphilitic sera from patients with various stages of syphilis were tested. By using clinical histories, the specificity with 148 nonsyphilitic sera was determined to be 100% for the HATTS and 96.6% (143 of 148) for the FTA-ABS. Satisfactory reproducibility was obtained with both methods. Compared with the FTA-ABS, the HATTS was more specific, easier, and more economical to perform. We therefore recommend the HATTS as a suitable alternative to the FTA-ABS.

Economic evaluation of maternal screening to prevent congenital syphilis

Benefit-cost analysis was applied to a model of first-trimester screening for syphilis where approximately ten new cases of early infections are identified and treated per 50,000 pregnancies. The cost of the screening is estimated to be +4.60 (U. S.) per participating woman, while the benefit-cost ratio was 3.8; thus the economic benefits are nearly four times the cost of the program. Furthermore, there are many other beneficial factors that cannot be evaluated in terms of money. The validity of the results varies with discount rates, frequencies of syphilitic infection, and rates of transmission to the fetus. If the incidence of maternal syphilis is 0.005%, the benefits equal the costs of the prevention program. In Norway, prenatal screening has been obligatory for 30 years. This represents a net benefit, or a total savings, of +8.6 million (U. S.; 1979). From an economic point of view, the first-trimester serologic screening should continue unabridged, whereas an extended preventive program, including premarital screening or additional third-trimester serologic tests, may not be advisable in Norway.

Routine screening of hospital blood samples for syphilis. A pilot study in Mount Isa, Queensland

During a seven-month study, 4005 blood samples taken for haematological investigations at the Mount Isa Base Hospital, Queensland, were routinely screened for syphilis. Two hundred and twenty-nine of these yielded serological evidence of syphilis. One hundred and eighty-eight persons were either aware of, or had recorded evidence of, previous infection. Serological evidence of hitherto unsuspected syphilis was found in 24 persons. Seventeen persons with serological evidence of syphilis, but without a recorded history of the disease, could not be contacted. The relatively high prevalence (1%) of undetected syphilis in this population sample led to the continuation of routine screening at Mount Isa Base Hospital. Hospitals which serve towns with similar demographic profiles may find routine screening for syphilis of all blood samples, taken for unrelated investigations, a useful procedure.

Repeal of mandated premarital tests for syphilis: a survey of state health officers

Statistics on the mandated premarital tests for syphilis (PMSTs) in the United States for the year 1978 were analyzed to determine whether this program is epidemiologically and economically effective. Overall close to four million PMSTs contributed 1.27 per cent of the tests found positive for infectious syphilis in the 44 states where PMSTs are mandated. Of all mandated PMSTs, only one in 8,461 was positive for infectious syphilis. In a companion study, venereal disease control officers were canvassed for their opinions regarding the retention or abolition of the mandatory tests. Out of 44 states which mandated tests, only 13 respondents favored retention while 31 found the program unsatisfactory, preferred abolition or changes, or were undecided.

Routine Serologic Testing for Syphilis in a Community Medical Practice

A retrospective review of 8,100 serologic tests for syphilis ordered during a 42-month period yielded positive rapid plasma reagin test results in 127 patients (1.6 percent) and a positive fluorescent treponemal antibody absorption reaction in 91 patients (1.1 percent). Of the 36 cases of biologic false-positive reactions, most were in prenatal patients. Forty-six cases of syphilis were previously undiagnosed but antibiotic therapy was given in only 26 of the patients. Some 24 percent of syphilitic patients were not treated because the positive serologic findings were overlooked. Cerebrospinal fluid determinations were analyzed and cost-effectiveness of finding a single case of previously undiagnosed syphilis was calculated. We found that routine serologic tests and cerebrospinal fluid studies for syphilis in asymptomatic patients had low rates of positivity in our community hospital and outpatient practice.

Cost-benefit analysis of a prenatal preventive programme against congenital syphilis

Serologic screening of pregnant women to prevent congenital syphilis has been obligatory in Norway since 1948. Today the incidence of unrecognized, untreated maternal syphilis is approximately 0.2 per 1000 pregnancies. A cost-benefit model is applied to the current prenatal screening programme in Norway. Although may of the benefit parameters are given only an approximate value, or are not valued at all, it was found that the benefit-cost ratio was nearly 2 (1.9), indicating that the economic benefits or savings to the society represent twice the cost of the preventive programme.

Paying for diagnostic accuracy

One of the difficult problems facing managers is how to evaluate the benefits to be gained from introducing a new diagnostic test that may be more accurate--but also more expensive. What analyses can be applied to help the hospital make the choice to switch or not?