Victoria Pope

Maternal and congenital syphilis in Bolivia, 1996: prevalence and risk factors

OBJECTIVES The present study was carried out in seven maternity hospitals to determine the prevalence of maternal syphilis at the time of delivery and the associated risk factors, to conduct a pilot project of rapid syphilis testing in hospital laboratories, to assure the quality of syphilis testing, and to determine the rate of congenital syphilis in infants born to women with syphilis at the time of delivery--all of which would provide baseline data for a national prevention programme in Bolivia. METHODS All women delivering either live-born or stillborn infants in the seven participating hospitals in and around La Paz, El Alto, and Cochabamba between June and November 1996 were eligible for enrolment in the study. FINDINGS A total of 61 out of 1428 mothers (4.3%) of live-born infants and 11 out of 43 mothers (26%) of stillborn infants were found to have syphilis at delivery. Multivariate analysis showed that women with live-born infants who had less than secondary-level education, who did not watch television during the week before delivery (this was used as an indicator of socioeconomic status), who had a previous history of syphilis, or who had more than one partner during the pregnancy were at increased risk of syphilis. While 76% of the study population had received prenatal care, only 17% had syphilis testing carried out during the pregnancy; 91% of serum samples that were reactive to rapid plasma reagin (RPR) tests were also reactive to fluorescent treponemal antibody-absorption (FTA-ABS) testing. There was 96% agreement between the results from local hospital laboratories and national reference laboratories in their testing of RPR reactivity of serum samples. Congenital syphilis infection was confirmed by laboratory tests in 15% of 66 infants born to women with positive RPR and FTA-ABS testing. CONCLUSION These results indicate that a congenital syphilis prevention programme in Bolivia could substantially reduce adverse infant outcomes due to this disease.

Molecular subtyping of Treponema pallidum from North and South Carolina.

ABSTRACT Patients from five clinics in North and South Carolina who had lesions suggestive of primary or secondary syphilis were evaluated using molecular techniques that allow the differentiation of Treponema pallidum strains on the basis of two variable genes, tpr and arp. Lesion samples were screened for the presence of T. pallidum DNA using PCR for polA, which represents a segment of the polymerase I gene that is unique to the spirochete. Twenty-seven of 154 lesion samples were found to contain T. pallidum, 23 of which had typeable DNA. Seven molecular subtypes were found (10f, 12f, 13f, 14f, 14g, 15f, and 16f); one to four subtypes were identified at each clinic. Subtype 14f was found in 52% of the typeable specimens and was distributed in four of the five clinics. Subtype 16f was found in 22% of specimens and was concentrated at one clinic. Further data are needed to define the role of this technique in examining the epidemiology of syphilis.

Prevalence of Syphilis Seroreactivity in the United States: Data From the National Health and Nutrition Examination Surveys (nhanes) 2001–2004

Background: There have been no recent US population-based estimates of syphilis seroprevalence. We determined the prevalence of syphilis seroreactivity among a representative sample of the US population. Methods: Sera from 18- to 49-year-old participants in the National Health and Nutrition Examination Surveys 2001–2004 were tested for syphilis IgG antibody using an enzyme immunoassay (EIA). Specimens with positive or indeterminate EIAs underwent rapid plasma reagin (RPR) testing; RPR titers ≥1:8 were considered positive. Specimens with RPR titers <1:8 underwent confirmatory testing with Treponema pallidum particle agglutination (TP-PA). Results: Sera were available for 5767 participants. EIA testing was positive or indeterminate for 126, of which 10 had RPR titers ≥1:8. Of the remaining 116 specimens, 60 had positive TP-PA tests, including all 19 with RPR titers >1:1. Overall weighted syphilis seroprevalence was 0.71% (95% CI: 0.51–0.96). Prevalence was similar among males (0.76%) and females (0.67%) and increased with age, less education, and lower income (P <0.001 for each). Non-Hispanic blacks had the highest prevalence (4.3%), followed by Mexican-Americans (0.98%) and non-Hispanic whites (0.07%; P <0.001). Conclusions: The prevalence of syphilis seroreactivity was low (0.71%) in the general US population of 18- to 49-year-olds. However, consistent with surveillance data, this nationally representative survey showed substantial disparities in syphilis by race/ethnicity.

Treponemal specific tests for the serodiagnosis of syphilis

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.

Syphilis Fast Latex Agglutination Test, a Rapid Confirmatory Test

ABSTRACT Using 255 serum samples with various reactivities, we evaluated the Syphilis Fast latex agglutination test (Syphilis Fast) against theTreponema pallidum particle agglutination test (TP-PA) for confirming a diagnosis of syphilis. We found 98.8% agreement between the Syphilis Fast and the TP-PA. The Syphilis Fast, however, had a couple of advantages over the TP-PA: the test takes only 8 min to perform and produces results that are easy to read. It appears to be a good confirmatory test for syphilis, especially for point-of-care clinics such as prenatal or sexually transmitted disease clinics.

Use of Synthetic Cardiolipin and Lecithin in the Antigen Used by the Venereal Disease Research Laboratory Test for Serodiagnosis of Syphilis

ABSTRACT The Venereal Disease Research Laboratory (VDRL) test is a microflocculation test for syphilis that uses an antigen containing cardiolipin, lecithin, and cholesterol. For more than 50 years, the preparation of natural cardiolipin and lecithin for this test has been based on the Pangborn method which involves isolating and purifying these components from beef hearts. This process is tedious and time-consuming and results in a variable purity range. In our studies, we found that a VDRL antigen using synthetic tetramyristoyl cardiolipin and synthetic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (lecithin) was as specific in detecting syphilis as a VDRL antigen made with natural components. In 85% of the cases, we obtained an endpoint titer of 1/2 or 1 dilution more than a titer obtained with a VDRL antigen made with natural components. The use of these pure synthetic compounds, with a purity of 99%, would offer advantages in the standardization and stability of the VDRL antigen. Because this antigen is the basic ingredient in the preparation of nontreponemal reagents such as the rapid plasma reagin, toluidine red unheated serum test, and the unheated serum reagin, the use of this synthetic VDRL antigen should also increase the reactivity of these reagents.

Lipid Removal from Human Serum Samples

ABSTRACT The efficacy of lipid removal from human serum samples obtained by using Cleanascite HC, a commercially available product, was compared to that obtained by the standard chloroform method. Separate samples of 21 frozen, banked human serum samples used in the preparation of samples for proficiency testing were treated with either Cleanascite HC or chloroform. The lipid content was measured before and after treatment. The total percentages of lipid removed ranged from 61 to 70% with Cleanascite HC and from 60 to 62% with chloroform. The advantage of Cleanascite HC over chloroform is based on the simplicity of the procedure with Cleanascite HC without the environmental concerns inherent in the use of chloroform. In 15 serum samples known to contain antibodies to treponemal and nontreponemal syphilis antigens, Cleanascite HC bound some immunoglobulin, but with only minimal loss of reactivity in the serologic tests for syphilis. Cleanascite HC is therefore an acceptable alternative to chloroform for lipid reduction in human serum samples.

Defibrination of Blood Plasma for Use in Serological Tests for Syphilis

ABSTRACT Syphilitic plasma can be salvaged from discarded blood donations and converted to serum by defibrination. Sixty-nine units of plasma were treated with a stock solution of 100 U of thrombin per ml in 1 M calcium chloride and then with a 10% (wt/vol) solution of kaolin. Fibrinogen concentrations detected in initial plasma samples ranged from 94 to 4,970 mg/liter (mean, 2,532 mg/liter) for samples that were reactive by the rapid plasma reagin circle card test (RPR) and from 314 to 2,742 mg/liter (mean 1,528 mg/liter) for samples that were not reactive by the RPR. The treated samples showed no measurable fibrinogen remaining after the defibrination process. In the nontreponemal RPR for syphilis, 86% of the treated plasma samples retained the same endpoint titer as that of the initial plasma sample. When the Treponema pallidum passive-particle-agglutination test was used, 98% retained the same reactivity. In the Captia Syphilis-G enzyme immunoassay, 89% of the treated samples demonstrated no change in reactivity index, and in the fluorescent treponemal antibody absorption test, 96% showed no reduction in fluorescence. Human sera containing antibodies to syphilis are used at the Centers for Disease Control and Prevention for the preparation of reference controls or as samples for proficiency testing. Finding reactive sera is becoming more difficult due to the general decline of syphilis cases in the United States. The decreasing availability of these sera can be alleviated by salvaging plasma and converting it to serum.

Four serologic tests for syphilis: results with comparison of selected groups of sera

The specificity of the fluorescent treponemal antibody-absorbed (FTA-Abs) test was assessed for 17 sera from syphilitic patients that were nonreactive in the Treponema pallidum immobilization (TPI) test but reactive in the FTA-Abs test. Thirty-three other sera from syphilitic patients and 19 sera from nonsyphilitic individuals were also examined by fluorescent treponemal and microhemagglutination Treponema pallidum (MHA-TP) tests and by the enzyme-linked immunosorbent assay (ELISA). Specific absorptions of sera with calf thymus DNA or Treponema pallidum biotype Reiter (Reiter treponemes) were performed. In quantitative immunofluorescence assays (IFA) with antihuman IgG and IgM conjugates, results were similar to those for reactive sera from a control group. Results of both the MHA-TP and ELISA tests supported the specificity of the FTA-Abs test; reactivity in the latter was not removed by specific absorption either with calf thymus DNA or with Reiter treponemes. This evaluation suggests a format for serodiagnosis in cases in which test results are discrepant.

Excellence in sexually transmitted infection (STI) diagnostics: recognition of past successes and strategies for the future.

Diagnostic advances do not generally receive the recognition given to prevention and treatment contributions, for the control and management of infectious diseases including sexually transmitted infections (STIs). In order to identify seminal diagnostic contributions over a half century (1950–2000), the Editorial Board of the WHO Sexually Transmitted Diseases Diagnostics Initiative (SDI) Publication Review or “electronic journal club” were asked to nominate their choices of peer-reviewed publications for special recognition. From 43 nominations, 13 were voted by a panel of 25 “experts” as having made the most significant contributions. The 1964 article by Thayer and Martin, which identified a selective media for gonococcal culture, was chosen unanimously by all panel members and is identified as the classic STI diagnostic article for this era.