Clinical manifestations of early syphilis by HIV status and gender: results of the syphilis and HIV study.

BACKGROUND: Despite reports of unusual clinical presentations and therapeutic responses among HIV-infected patients with syphilis, syphilis has not been regarded as a serious opportunistic infection that predictably progresses among most HIV-coinfected patients. GOAL: To define and describe differences in the presentation and response to treatment of early syphilis among HIV-infected and HIV-uninfected patients, to describe any differences by gender, and to determine if clinical presentation of central nervous system involvement predicted serologic failure. DESIGN: A prospective, multicenter, randomized, controlled trial of enhanced versus standard therapy to compare the benefit of enhanced therapy, the clinical importance of central nervous system involvement, and the clinical manifestations of early syphilis infection among HIV-infected and HIV-uninfected patients. RESULTS: The median number of ulcers was significantly greater among HIV-infected and HIV-uninfected patients, as was the percent of HIV-infected patients with multiple ulcers. Among patients diagnosed with secondary syphilis, a higher percentage of HIV-infected patients presented with genital ulcers [13/53 (25%)] than did HIV-uninfected patients [27/200 (14%)]. No differences between HIV-infected and HIV-uninfected patients were detected for other secondary syphilis manifestations. Although women presented more frequently with secondary syphilis than did men, no other gender differences in clinical manifestations were noted. Neurologic complaints were reported most frequently among patients with secondary syphilis [103/248 patients (42%)] compared with patients with primary syphilis [32/136 (24%)] and early latent syphilis [48/ 142, (34%)] (P < 0.05), but no differences in neurologic complaints were apparent by HIV status or CSF abnormalities. No neurologic complaints were significantly associated with serologic treatment failures at 6 months. CONCLUSIONS: Overall, HIV infection had a small effect on the clinical manifestations of primary and secondary syphilis. Compared with HIV-uninfected patients, HIV-infected patients with primary syphilis tended to present more frequently with multiple ulcers, and HIV-infected patients with secondary syphilis presented with concomitant genitals ulcers more frequently.

High prevalence and incidence of sexually transmitted diseases in urban adolescent females despite moderate risk behaviors.

To better understand the prevalence, incidence, and risk factors for sexually transmitted diseases (STDs) among female adolescents, a prospective 6-month cohort study was conducted at four teen clinics in a southeastern city. At enrollment, 260 (40%) of 650 sexually active females ages 14-19 years had an STD: chlamydia, 27%; herpes simplex virus type 2 (HSV-2), 14%; gonorrhea, 6%; trichomoniasis, 3%; and hepatitis B, 2%. At follow-up, 112 (23%) of 501 participants had an incident infection: chlamydia, 18%; HSV-2, 4%; gonorrhea, 4%; and trichomoniasis, 3%. At either enrollment or follow-up, 53% had >/=1 STD; of those with 1 lifetime partner, 30% had an STD. Having a new partner (odds ratio [OR], 2.2; 95% confidence interval [CI], 1. 1-4.2) or friends who sell cocaine (OR, 1.6; CI, 1.0-2.6) was independently associated with incident infection. STD incidence and prevalence were extremely high in this population, even in teenagers with only 1 lifetime partner. Individual risk behaviors appeared less important for STD risk than population factors.

Treatment of syphilis, 1998: nonpregnant adults.

Questions regarding the appropriate therapy for syphilis remain, despite the many years during which this infection has been subjected to intense scientific scrutiny. In an effort to provide guidance for the development of the 1998 sexually transmitted disease (STD) treatment guidelines of the Centers for Disease Control and Prevention (CDC), these questions were outlined and an effort to answer them was made. Articles relating to syphilis treatment published after the previous revision of the CDC STD treatment guidelines (in 1993) and by the end of 1996 were identified with use of MEDLINE. Abstracts from relevant scientific meetings held during that time were also examined. Reference was also made to older literature, and expert opinion was sought. Conclusions were reached and recommendations were made on the basis of published evidence wherever possible.

Effect of the interval between pregnancies on perinatal outcomes.

BACKGROUND: A short interval between pregnancies has been associated with adverse perinatal outcomes. Whether that association is due to confounding by other risk factors, such as maternal age, socioeconomic status, and reproductive history, is unknown. METHODS: We evaluated the interpregnancy interval in relation to low birth weight, preterm birth, and small size for gestational age by analyzing data from the birth certificates of 173,205 singleton infants born alive to multiparous mothers in Utah from 1989 to 1996. RESULTS: Infants conceived 18 to 23 months after a previous live birth had the lowest risks of adverse perinatal outcomes; shorter and longer interpregnancy intervals were associated with higher risks. These associations persisted when the data were stratified according to and controlled for 16 biologic, sociodemographic, and behavioral risk factors. As compared with infants conceived 18 to 23 months after a live birth, infants conceived less than 6 months after a live birth had odds ratios of 1.4 (95 percent confidence interval, 1.3 to 1.6) for low birth weight, 1.4 (95 percent confidence interval, 1.3 to 1.5) for preterm birth, and 1.3 (95 percent confidence interval, 1.2 to 1.4) for small size for gestational age; infants conceived 120 months or more after a live birth had odds ratios of 2.0 (95 percent confidence interval, 1.7 to 2.4);1.5 (95 percent confidence interval, 1.3 to 1.7), and 1.8 (95 percent confidence interval, 1.6 to 2.0) for these three adverse outcomes, respectively, when we controlled for all 16 risk factors with logistic regression. CONCLUSIONS: The optimal interpregnancy interval for preventing adverse perinatal outcomes is 18 to 23 months.

Treponemal specific tests for the serodiagnosis of syphilis. Syphilis and HIV Study Group.

OBJECTIVES: To determine the rate of concordance of the Microhemagglutination Assay for Antibodies to T. pallidum (MHA-TP) and the Fluorescent Treponemal Antibody-Absorption test (FTA-ABS) prior to therapy in patients with early stage syphilis and to assess the incidence of and associated risk factors for seroreversion of these treponemal specific tests during the first year after therapy for early syphilis. DESIGN: Multicenter, prospective, cohort treatment study of patients with early syphilis. METHODS: Five hundred twenty-five patients were enrolled in a study to evaluate the response of early syphilis to either benzathine penicillin 2.4 million units intramuscularly once or this therapy plus amoxicillin 2 g and probenecid 500 mg orally both three times daily for 10 days. Serologic and clinical follow-up was conducted at intervals over 1 year. MHA-TP and FTA-ABS tests were performed on serologic specimens from each patient visit. RESULTS: Enrollment specimens showed 5% discordant MHA-TP and FTA-ABS results with 85% of these demonstrating a nonreactive MHA-TP. This occurred most commonly in primary syphilis. In patients who had a 1-year serologic follow-up with FTA-ABS or MHA-TP, seroreversion occurred in 9% and 5% of cases, respectively. No association between HIV-seropositivity and TST seroreversion was demonstrated. CONCLUSION: The MHA-TP may be less sensitive than the FTA-ABS for identifying patients with primary syphilis. Treponemal specific tests may become nonreactive during the first year after therapy for early syphilis.

The changing paradigm of sexually transmitted disease control in the era of managed health care.

Several trends in sexually transmitted diseases (STDs) have laid the foundation for a new paradigm for STD treatment and prevention that encompasses a community-wide, population-oriented approach. Public health STD programs, in partnership with a wide variety of community collaborators, will need to carry out the essential functions of public health-assessment, policy development, and assurance-by developing resources for community organizing and planning, enhanced information systems, and comprehensive training programs for professional staff and community partners. Community providers (particularly practicing clinicians and community and hospital clinics) will need to deliver primary prevention (community health promotion and clinical preventive services) and secondary prevention (screening and treatment) services while categorical STD clinics focus on providing care for high-risk, high-frequency STD transmitters who serve as the reservoir for much of a community's bacterial STDs. Managed care organizations and public health STD programs will need to formalize collaborative arrangements and capitalize on the strengths of each organization in order to have a population-level impact on STD transmission.

A randomized trial of enhanced therapy for early syphilis in patients with and without human immunodeficiency virus infection. The Syphilis and HIV Study Group.

BACKGROUND: Reports of neurosyphilis and invasion of cerebrospinal fluid by Treponema pallidum in patients with human immunodeficiency virus (HIV) infection have led to doubts about the adequacy of the recommended penicillin G benzathine therapy for early syphilis. METHODS: In a multicenter, randomized, double-blind trial, we assessed two treatments for early syphilis: 2.4 million units of penicillin G benzathine and that therapy enhanced with a 10-day course of amoxicillin and probenecid. The serologic and clinical responses of patients with and without HIV infection were studied during one year of follow-up. RESULTS: From 1991 through 1994, 541 patients were enrolled, including 101 patients (19 percent) who had HIV infection but differed little from the uninfected patients in their clinical presentations. The rates at which chancres and rashes resolved did not differ significantly according to treatment assignment or HIV status. Serologically defined treatment failures were more common among the HIV-infected patients. The single clinically defined treatment failure was in an HIV-infected patient. Rates of serologically defined treatment failure did not differ according to treatment group (18 percent at six months with usual therapy; 17 percent with enhanced therapy). T. pallidum was found at enrollment in the cerebrospinal fluid of 32 of 131 patients (24 percent) and after therapy in 7 of 35 patients tested. None had clinically evident neurosyphilis, and the rate of detection of T. pallidum did not differ according to HIV status. CONCLUSIONS: After treatment for primary or secondary syphilis, the HIV-infected patients responded less well serologically than the patients without HIV infection, but clinically defined failure was uncommon in both groups. Enhanced treatment with amoxicillin and probenecid did not improve the outcomes. Although T. pallidum was detected in cerebrospinal fluid before therapy in a quarter of the patients tested, such a finding did not predict treatment failure. The current recommendations for treating early syphilis appear adequate for most patients, whether or not they have HIV infection.

Epidemiology of syphilis in the United States, 1941--1993.

BACKGROUND AND OBJECTIVES: The distribution and trends of syphilis are influenced by biologic factors, sexual behaviors, biomedical technology, availability of and access to health care, public health efforts, changes in population dynamics, and sociocultural factors. The objective of this article is to review the epidemiology of syphilis in the United States during the period 1941-1993 in the context of some of these factors. STUDY DESIGN: Surveillance data on cases of syphilis and congenital syphilis reported by state and city health departments to the Centers for Disease Control and Prevention were analyzed to show distribution and trends by geographic location, racial and ethnic groups, gender, and age. RESULTS: Historically, syphilis was distributed widely throughout the country and declined rapidly after the introduction of penicillin therapy and broad-based public health programs, attaining its lowest levels in the 1950s. However, in recent years, the disease has returned and become focused in the southern region and in urban areas outside that region. Rates of syphilis have remained highest in black Americans, and the most recent national epidemic of syphilis primarily involved them. Rates in white men were at intermediate levels during the early 1980s but have declined to low rates in the 1990s, possibly because of changes in behavior in response to the AIDS epidemic. Rates in white women and other racial and ethnic groups have remained low throughout the 1980s and 1990s. CONCLUSIONS: Syphilis remains a significant problem in the United States, and its epidemiology is influenced by a complex combination of factors. To prevent and control syphilis effectively, public health practitioners must understand these factors and design programs and interventions that address the disease in the context of these factors.

Impact of increased legal access to needles and syringes on community pharmacies' needle and syringe sales--Connecticut, 1992-1993.

In May 1992, the Connecticut legislature passed new laws aimed at increasing injecting drug users' (IDUs) access to sterile needles and syringes (syringes); as of July 1992, pharmacists were permitted to sell and individuals were permitted to possess up to 10 syringes without medical prescriptions (nonprescription syringes). We evaluated the impact of the new laws by conducting (1) prospective surveillance of syringe sales and policies at selected community pharmacies (pharmacies) and (2) a telephone survey of pharmacy managers' reports of syringe sales and policies at a statewide stratified random sample of pharmacies. Our data provide direct evidence that most, but not all, Connecticut pharmacies sold nonprescription syringes when permitted to do so by the new laws. For example, using the telephone survey data, we estimate that during November, 1993, 83% [95% CI: 77-89%] of all Connecticut pharmacies sold nonprescription syringes and 56,000 [95% CI: 44,000-68,000] nonprescription syringes were sold, during November 1993. Our data provide indirect evidence that IDUs were purchasing nonprescription syringes at pharmacies. For example, in five Hartford pharmacies located in neighborhoods where injection drug use was prevalent, the total number of nonprescription syringes sold per month increased significantly from 460 in July 1992 to 2,482 in June 1993 (p = 0.0001). The data suggest that the new laws increased IDUs' access to sterile syringes in Connecticut.

Control of epidemic early syphilis: the results of an intervention campaign using social networks.

BACKGROUND: During an epidemic of early syphilis, social networks were used for an intervention campaign. GOAL OF THIS STUDY: To characterize the epidemic and describe the yield of new cases from index-case interviews. METHODS: Analyses of morbidity data collected by the Montgomery County, Alabama, sexually transmitted disease program determined the course of the epidemic and characterized the new case yields from social networks identified via index-case interviews (partner notification investigations) and interviews with sex partners and their associates (cluster investigations). Results and costs were compared to a noncampaign period. RESULTS: The number of reported syphilis cases nearly doubled from 1990 to 1991 (201 to 348 per 100,000 residents). During the 21-week campaign, 373 case-patients had partner notification/cluster investigations; 113 (11%) of 984 sex partners and 41 (3%) of 1,146 high-risk associates (persons identified during cluster investigations) had syphilis. No subgroup of case-patients for which the partner notification/cluster investigation yielded more infected persons than other subgroups was identified. The cost per case detected was more than twice that during a noncampaign period ($1,627 vs. $771). CONCLUSION: Partner notification investigations yielded more infected persons than cluster investigations. Further evaluation is needed to determine the role of intense partner notification/cluster investigators' efforts in the control of epidemic syphilis.

Treatment of syphilis, 1993.

Data on treatment of patients with syphilis were reviewed in preparation for revision of the Sexually Transmitted Disease Treatment Guidelines of the Centers for Disease Control and Prevention. Published studies of treatment regimens available and practical for use today were reviewed, particularly in regard to the following issues: treatment for primary, secondary, and latent stages of syphilis; treatment for syphilis during pregnancy; treatment for syphilis in human immunodeficiency virus (HIV)-infected patients; and serological criteria for evaluating response to treatment. The results of treatment and the methodological quality of the studies was considered. Most treatment recommendations must be based on expert judgment and with reliance on the clinical experience over 4 decades. For the treatment of early syphilis in HIV-uninfected patients, this is probably sufficient. Data about HIV-infected patients are insufficient both for determining whether current therapy is adequate and for recommendation of an alternative if a change in therapy is deemed necessary.

Syphilis in San Diego County 1983-1992: crack cocaine, prostitution, and the limitations of partner notification.

BACKGROUND AND OBJECTIVES: Recent epidemics of syphilis have been associated with crack cocaine use and anonymous sex for drugs, suggesting a potential limitation of sex partner notification as a disease control strategy. To assess these factors in an inner city epidemic of syphilis in San Diego County, California, we performed a descriptive epidemiologic analysis. STUDY DESIGN: Descriptive epidemiologic data were obtained from case investigation reports of primary and secondary syphilis. RESULTS: In the middle and late phases of the epidemic (1990-1992), the incidence of syphilis in the inner city area was more than six times that in remainder of the county. Illegal drug use was reported by 30% of patients. Drug use, especially crack cocaine, was related to prostitution. The estimated total number of sex partners per patient ratio was 4.2, whereas the named sex partners per patient ratio was only 1.5. Twenty-two percent of patients did not report any named partners. Overall, only 26% of the estimated total number of sex partners received treatment. CONCLUSIONS: Expanding partner notification to include more high-risk persons identified through social networks and increasing screening among high-risk populations may improve control of inner city drug/prostitution-related syphilis epidemics.

Primary infertility: characteristics of women in North America according to pathological findings.

STUDY OBJECTIVE: To determine, in women with primary infertility, whether specific characteristics or behavioural factors are associated with the various pathological conditions identified as contributing to the infertility. DESIGN: Case-control study. SETTING: Seven institutions in the USA or Canada. PARTICIPANTS: Study subjects were 1750 women who presented with primary infertility, among whom the main pathological cause of infertility was male factor (417), tubal obstruction (231), endometriosis (194), luteal phase defects (153), other ovulatory problems (193), cervical abnormalities (92), and polycystic ovarian disease (84) and 1765 control women who delivered their first child at the same institution. MAIN RESULTS: Except for tubal obstruction and polycystic ovarian disease, the characteristics and behaviours of the women with infertility did not differ appreciably according to the pathological conditions recorded. Women with tubal obstruction had had more sexual partners, an earlier age at first intercourse, were more likely to have used an intrauterine device but less likely to have used a condom, and were more likely to have smoked cigarettes and to have used various recreational drugs than the other women. Women with polycystic ovarian disease were more obese, had had fewer sexual partners, and were less likely to have used cigarettes, contraceptives, and recreational drugs than the other women. CONCLUSIONS: Sexually transmitted infections seem to increase the risk of tubal obstruction but not other causes of infertility. Obesity is associated with polycystic ovarian disease. These data offer few clues to the aetiology of infertility attributed to endometriosis, cervical abnormalities, luteal phase defects, other ovulatory defects, or to male factors.

High rate of HIV seroconversion among patients attending urban sexually transmitted disease clinics.

OBJECTIVE: To study rates of documented HIV seroconversion and syphilis as a cofactor for seroconversion in sexually transmitted disease (STD) clinics. In the main clinic the HIV seroprevalence rate was 12% and most infections had been shown to be acquired by heterosexual contact. METHODS: We analyzed computer records of patients who had at least two HIV-antibody tests between 1 December 1987 and 31 December 1990, at STD clinics in Dade County (Miami), Florida. RESULTS: Of 5164 individuals with two HIV tests, 208 (4.0%) seroconverted. The overall seroconversion rate was 3.1 per 100 person-years. Among blacks, who accounted for 77% of seroconversions, the rate was higher for women (4.8) than for men (2.7). The highest rate was in 15-19-year-old black women (7.1 per 100 person-years). The HIV seroconversion rate was 12.8 for patients with primary or secondary syphilis diagnosed between two HIV tests, 3.1 for patients who acquired syphilis before their first HIV test, and 2.3 for patients who had never had syphilis. Eighteen per cent of all HIV seroconversions were attributable to syphilis acquired in the interval between two HIV tests. CONCLUSIONS: We found high HIV seroconversion rates, especially among black teenagers and black women, in an STD clinic population in which the majority of HIV infections were shown previously to have been acquired heterosexually. Syphilis was a marker for HIV seroconversion and syphilitic ulcers may facilitate HIV transmission. Innovative prevention programs directed towards women and adolescents should be developed and evaluated.

Development of sexually transmitted diseases treatment guidelines, 1993. New methods, recommendations, and research priorities. STD Treatment Guidelines Project Team and Consultants.

To develop the 1993 Sexually Transmitted Diseases Treatment Guidelines, experts from the Centers for Disease Control and Prevention reviewed the literature on sexually transmitted disease treatment, assembled tables of evidence, and listed key questions on therapeutic outcome: microbiologic cure, alleviation of symptoms, and prevention of sequelae and transmission. At a meeting with external experts, evidence was systematically assessed and guidelines developed. Quality of evidence for microbiologic cure was generally good for gonorrhea and chlamydia, poor for syphilis, and fair for most other diseases. Evidence on preventing sequelae and transmission was limited. The Guidelines include new recommendations for single-dose oral therapy of gonorrhea (cefixime, ciprofloxacin, and ofloxacin), chlamydia (azithromycin), and chancroid (azithromycin); outpatient therapy of pelvic inflammatory disease (ofloxacin and either clindamycin or metronidazole); and patient-applied therapy of genital warts (podofilox). Syphilis therapy did not change substantially. Several global issues that emerged during the development of the World Health Organization Recommendations for the Management of Sexually Transmitted Diseases also are discussed. This evidence-based approach clarified important treatment issues and the rationale for recommendations, and identified research priorities.

Fertility and use of cigarettes, alcohol, marijuana, and cocaine.

This study demonstrated that cigarette smoking was associated with an increase in both time to conception (among 2817 fertile women) and risk of primary infertility (among 1818 infertile women and their primiparous control subjects). The average time to conception was 4.3 months for women who never smoked, 4.6 months for those who smoked in the past, and 5.1 months for those who currently smoked. The delay in conception for current smokers remained significant after adjusting for confounders (risk ratio of 0.9 (0.8 to 1.0)). Additionally, current smokers were at increased risk of primary infertility (odd ratios of 1.9 (1.5 to 2.3)). For alcohol use, the average time to conception and risk of primary infertility did not vary by level of consumption. The average time to conception was significantly shorter for women who had used marijuana regularly and for women who had ever used cocaine than for women who had never used these drugs. Because of the increased use of marijuana and cocaine among young adults, further investigations of these associations are needed.

Surveillance for primary and secondary syphilis--United States, 1991.

PROBLEM/CONDITION: From 1986 through 1990, an epidemic of syphilis occurred throughout the United States. In 1991, the number of reported cases of primary and secondary (P&S) syphilis in the United States declined for the first time since 1985. REPORTING PERIOD COVERED: To examine how this decline reflected sex-specific, race/ethnicity-specific, and regional patterns of syphilis morbidity, we analyzed data for syphilis cases reported to CDC from 1984 through 1991. DESCRIPTION OF SYSTEM: Summary data for cases of syphilis reported to state health departments were sent quarterly and annually to CDC. The quarterly data from each state included total number of syphilis cases by sex, stage of disease (primary, secondary, early latent, and late latent), and source of report (public or private). The annual data from each state included total number of P&S syphilis cases by sex, racial/ethnic group (white, not of Hispanic origin; black, not of Hispanic origin; Hispanic; Asian/Pacific Islander; or American Indian/Alaskan Native), 5-year age group, and source of report. RESULTS: The decline in both the number and rate of reported syphilis cases in 1991 occurred in every racial group in the United States and in both sexes. This decline also occurred in every region of the United States except the Midwest, where the total P&S syphilis rate increased 37.3% from 1990 through 1991. Despite the increase in syphilis rates in the Midwest, the highest rates of P&S syphilis in 1991 were reported from the South. INTERPRETATION: The reasons for the decline in syphilis are unclear. No data exist to conclusively identify which STD control program activities affected the level of syphilis morbidity or to what extent those activities may have contributed to the decline. Changes in drug use and limited immunity to Treponema pallidum may have accounted for some of the decrease in syphilis incidence. Higher levels of poverty in the South and poor access to health-care services associated with poverty probably contributed to continued high levels of disease transmission in the South. ACTIONS TAKEN: Better evaluation of STD control program activities will be necessary to help determine the most effective strategies for preventing and controlling syphilis in different high-risk populations.

A method to describe physician decision thresholds and its application in examining the diagnosis of coronary artery disease based on exercise treadmill testing.

The authors developed a method that utilizes logistic regression analysis to 1) calculate the disease probability with confidence intervals at which any specified proportion of physicians reaches a clinical decision, 2) statistically test whether factors other than disease probability affect this clinical decision, and 3) statistically test whether physician decision making in relation to disease probability varies by other factors. They apply the method to analyze the relationship between disease probability and the proportion of physicians who diagnosed coronary artery disease (CAD) in 127 consecutive subjects who completed the treadmill exercise tolerance test (ETT) at two hospitals. Twenty-five percent of the physicians decided that CAD was possible or definite at a post-ETT disease probability of 0.24 (95% CL= 0.07-0.35); 50% at 0.54 (95% CL = 0.43-0.70); and 75% at 0.82 (95% CL = 0.67-1.0). Multivariate logistic regression analysis revealed three factors significantly and independently related to the diagnosis of CAD: post-ETT disease probability, positive ETT result, and cigarette smoking. The proportion of physicians who reached a diagnosis of CAD did not differ by hospital setting (VA versus university), level of training (attending versus housestaff/fellow), or diagnosing service (cardiology versus other internal medicine). It is concluded that factors other than disease probability may affect physician diagnostic decisions.

Seroepidemiological characterization of a syphilis epidemic in the Republic of the Marshall Islands, formerly a yaws endemic area.

The annual numbers of reported cases of syphilis in the Republic of the Marshall Islands (RMI) increased from none in 1983 to more than 600 in 1989, suggesting a large outbreak of syphilis. Much of the increase resulted from expanded serological screening. The apparent outbreak of syphilis, therefore, may have been partly the result of increased surveillance or, since the RMI was formerly a yaws endemic area, possibly due to a resurgence of yaws. To address this problem and better characterize the epidemic, we analysed results from a 1989/90 Ministry of Health Services mass serological screening on Majuro Atoll, the main population centre. Serum specimens from 9160 people (86% of residents aged 15-44 years) on Majuro were screened with the rapid plasma reagin (RPR) card test; we repeated the RPR and performed a confirmatory microhaemagglutination assay for Treponema pallidum-specific antibodies (MHA-TP) on a sample of serum specimens. To estimate the seroprevalence of syphilis, we also tested a sample of RPR nonreactive specimens by MHA-TP. Among people less than 45 years of age, total (11.5%) and high-titre (5.2%) seropositivity rates were highest in the 20-24 year age group, as was MHA-TP seroprevalence (15.9%). These results suggested that a large outbreak of syphilis was responsible for the observed seroreactivity. Cumulative incidence modelling and comparisons with the results of a previous serosurvey conducted in 1985 suggested that the duration of the syphilis epidemic was approximately 10 years and that incidence had not increased appreciably since 1985.