Variations in sexual network connectivity may explain dramatic variations in sexually transmitted infection prevalence between populations and over time: a selected four-country analysis

Background: The incidence of sexually transmitted infections (STIs) has been noted to vary dramatically between population groups and over time. Here, the hypothesis that changes in network connectivity underpin these changes is explored.

Methods: The incidence/prevalence estimates of HIV, herpes simplex virus-2, syphilis, chlamydia, and gonorrhoea, as well as two markers of sexual network connectivity (partner concurrency and multiple partnering) by ethnic group and sexual orientation in Kenya, South Africa, the United Kingdom (UK) and the United States (USA) were extracted from published studies. Pearson’s correlation was used to test the association between the markers of network connectivity and the incidence/prevalence of these five STIs. A literature review was performed to evaluate the possible causes of the increases and decreases in syphilis incidence over the past 60 years.

Results: In each country, the five STIs were found to cluster in particular ethnic groups and sexual orientations and to be positively associated with the two markers of network connectivity. Syphilis incidence in the UK and USA was found to increase dramatically in the 1960s/1970s, decline in the 1980s and again increase in the late 1990s. These changes took place predominantly in men who have sex with men, and were preceded by corresponding changes in network connectivity. The large decline in antenatal syphilis prevalence in Kenya and South Africa in the 1990s were likewise preceded by declines in network connectivity.

Conclusions: Although other explanatory variables are not controlled for, the present analysis is compatible with the hypothesis that differential network connectivity is a parsimonious explanation for variations in STI incidence over time and between populations.

Comparison of RPR and ELISA with TPHA for the Diagnosis of Syphilis: Implication for Updating Syphilis Point-of-Care Tests in Ethiopia

Background

Syphilis is a sexually transmitted disease (STD) caused by the spirochete Treponema pallidum, and it persists to be a major public health problem in Africa, including Ethiopia. Syphilis diagnosis is made by either nontreponemal or treponemal approaches, though in developing countries the diagnosis relies mostly on nonspecific tests due to several reasons. Thus, the objective of this study was to assess the sensitivity, specificity, predictive values, and agreement of rapid plasma reagin (RPR) and enzyme-linked immunosorbent assay (ELISA) with Treponema pallidum hemagglutination assay (TPHA) as a gold standard for the diagnosis of syphilis.

Results

The sensitivity, specificity, and positive and negative predictive values of ECOTEST-RPR were 100%, 80.8%, 76.2%, and 100%, respectively. However, the sensitivity, specificity, and positive and negative predictive values of DIALAB-ELISA were 98.4%, 94.9%, 92.3%, and 98.9%, respectively. The agreement between DIALAB-ELISA and Randox-TPHA was excellent (kappa value: 0.96) as compared to ECOTEST-RPR and Randox-TPHA assay (kappa value: 0.88).

Conclusion

We found a characteristically variable performance of DIALAB-ELISA test and the currently available traditional ECOTEST-RPR test in the study area. The use of ECOTEST-RPR as a diagnostic test is confronted by its false positivity. Thus, neither the ECOTEST-RPR nor the DIALAB-ELISA test stands on its own to be used either as screening or confirmatory test for syphilis diagnosis. Consequently, thorough studies should be conducted aiming on a change of the current diagnostic scheme in the community.

Should All Pregnant Women be Screened for Syphilis?

In industrialized countries, the incidence of syphilis has decreased dramatically since the discovery of penicillin in the 1940s. However, syphilis and congenital syphilis are far from eradicated, especially in low- and middle-income countries. Syphilis in pregnant women is a cause of adverse pregnancy outcomes that can be prevented by screening for syphilis and early treatment in pregnancy. Several studies have found screening of pregnant women for syphilis to be a highly cost-effective intervention, even if the prevalence of syphilis is low. Obstacles to universal screening of pregnant women include low awareness of syphilis and low quality of antenatal care and healthcare in general in many low- and middle-income countries. For these settings, we need simpler and more reliable serological tests for syphilis, but we also need to strengthen health services in general to ensure sustainable antenatal care services to ensure sustainability of syphilis screening programmes.

Decline in syphilis seroprevalence among females of reproductive age in Northern Cape Province, South Africa, 2003-2012: utility of laboratory-based information

Strengthening current surveillance systems for syphilis is important to track and monitor disease burden. We used routinely collected laboratory information to generate surveillance estimates for syphilis trends among women of reproductive age (12-49 years) in the Northern Cape Province, a high syphilis burden region (2003 [8.6%] to 2011 [3.8%]) in South Africa. We extracted records meeting inclusion criteria from the National Health Laboratory Service electronic database for the period 2003-2012. A total of 286,024 women were included in the analysis. Syphilis seropositivity decreased between 2003 (5.7%) and 2012 (1.8%); p trend = 0.001, which was largely consistent with findings reported in the annual national syphilis and HIV survey from 2003 (8.6%) to 2011 (3.8%). Annually for the period from 2003 to 2012 there was an approximate 14% reduction in the prevalence ratio of syphilis seroprevalence (PR = 0.86, 95% CI = 0.85-0.87, p < 0.001). Three of five districts had significant decreases in syphilis seropositivity over this period. There were also declines in prevalence ratios for syphilis seropositivity for the various age groups for the period. This study shows that the national laboratory database in South Africa can be used as a complimentary surveillance tool to describe and understand trends in syphilis seroprevalence in South Africa.

The changing relationship between bacterial STIs and HIV prevalence in South Africa - an ecological study

Prevalence estimates of various bacterial sexually transmitted infections in South Africa have declined considerably since the mid-1990s. Syphilis among pregnant women, for example, declined from 10.8% in 1998 to 2.8% in 2001. We used Pearson's correlation coefficients to estimate the association between the prevalence of syphilis/male urethral discharge/male genital ulcers and the peak HIV prevalence at a district and provincial level in the early and late phases of the HIV epidemic in South Africa. Prevalence estimates of syphilis, male urethral discharge and male genital ulcers during the period preceding the peak HIV prevalence were all positively correlated with the peak HIV prevalence at a provincial level (Pearson's correlation coefficient [r] = 0.83, p = 0.006; r = 0.66, p = 0.052; r = 0.79, 0.011, respectively). These relationships all switched to a negative association later in the HIV epidemic at a provincial level (r = -0.53, p = 0.14; r = -0.73, p = 0.130; r = -0.54, p = 0.027, respectively). AIDS mortality may have played an important role in the decline of bacterial sexually transmitted infections such as syphilis in this region. Consequently, the relatively recent scale-up of antiretroviral therapy may result in a resurgence of syphilis and other sexually transmitted infections as observed in high-income countries.

Maternal syphilis and intimate partner violence in Bolivia: a gender-based analysis of implications for partner notification and universal screening

OBJECTIVES

Use a gender perspective to analyze a partner notification study conducted in antenatal clinics in Bolivia to assess the association between intimate partner violence (IPV) and partner notification.

GOAL

Guide the implementation of a safe, feasible, and culturally appropriate partner notification strategy in Bolivia in order to reduce the potential of IPV.

STUDY DESIGN

We conducted a cross-sectional survey with women (n = 209) and their notified partners (n = 137) and structured interviews with a subsample of participants.

RESULTS

Nearly 40% of women reported IPV in the past year and 28% mentioned fear of violence as a barrier to notifying their partners. Overall, 65% of women reported that they had notified their partners about their positive syphilis test results. Women who did not perceive violence as a barrier had greater odds of notifying their partner of their syphilis status (OR = 1.82; CI [0.93-3.60]; P <0.08). Women who could not protect themselves against partners' syphilis had a lower odds of notifying their partner (OR = 0.06; CI [0.049-0.656]; P <0.0001). Women who notified their partners said it was a favorable experience. Most men said they responded well to their partner's disclosure but could understand other men acting violently, especially when infidelity was involved.

CONCLUSIONS

The majority of women who participated were able to notify male partners of their positive syphilis diagnosis but also reported high levels of domestic violence. The data suggest that public health practitioners should concomitantly screen for IPV and syphilis during pregnancy and assist women in abusive relationships on how to communicate sensitive disclosure information to partners.

Is Sexually Transmitted Infection Management Among Sex Workers Still Able to Mitigate the Spread of HIV Infection in West Africa?

OBJECTIVE

To assess the role of sexually transmitted infection (STI) management to prevent HIV acquisition among sex workers in Burkina Faso.

DESIGN

Open cohort study of professional and nonprofessional sex workers with 3-month follow-up visits.

METHODS

Baseline and follow-up visits consisted of the administration of a behavioral questionnaire, education sessions on HIV and STIs, a medical examination, and laboratory testing for STI and HIV diagnosis.

RESULTS

Three hundred seventy-seven HIV-negative women were enrolled in the study. The cumulated HIV incidence was 3.2 per 100 person-years (Poisson 95% confidence interval: 1.9-4.9). Bacterial and parasitic STIs were low at baseline, whereas herpes simplex virus-2 (HSV-2) prevalence was 54.7%. By a Cox regression model, self-assessment of high HIV risk in the past, less than 5 clients per week, and no change of a steady partner were independently associated with HIV acquisition. Among STIs, only infection with HSV-2 tended to be associated with HIV acquisition (odds ratio = 2.45; P = 0.15). Overall, condom use increased during the study but to a lesser extent with steady partners.

CONCLUSIONS

Bacterial and parasitic STIs are no longer a key determinant of HIV acquisition, given the current stage of the outbreak in Burkina Faso. Although efforts for STI control should be maintained, strategies should focus on nonprofessional sex workers, steady partners, and HSV-2 infection to tackle HIV transmission further in this high-risk group.

Quality of sexually transmitted disease case management in Nairobi, Kenya: a comparison among different types of healthcare facilities

BACKGROUND

In Nairobi, the prevalence for sexually transmitted diseases (STDs) among attenders at antenatal and family planning clinics is substantial, but knowledge about the quality of STD case management is scarce.

GOAL

To assess quality of STD case management in Nairobi healthcare facilities.

STUDY DESIGN

All the facilities in five sublocations were enumerated. In 142 facilities, 165 providers were interviewed, observed during 441 interactions with patients who had STDs, and visited by a simulated patient.

RESULTS

For observations of patients with STDs, correct history-taking ranged from 60% to 92% among the various types of facilities, correct examination from 31% to 66%, and correct treatment from 30% to 75%. The percentage of correctness for all three aspects (World Health Organization prevention indicator 6) varied between 14% and 48%. Public clinics equipped for STD care performed best in all aspects, whereas treatment was poorest in pharmacies and private clinics. The providers trained in STD management performed better than those without training.

CONCLUSIONS

Quality of STD case management was unsatisfactory except in public STD-equipped clinics. This indicates the need for improvement by interventions such as further training in syndromic management, improved supervision, and the introduction of prepackaged syndromic management kits.

Syphilis control during pregnancy: effectiveness and sustainability of a decentralized program

OBJECTIVES

This study sought to assess the performance, effectiveness, and costs of a decentralized antenatal syphilis screening program in Nairobi, Kenya.

METHODS

Health clinic data, quality control data, and costs were analyzed.

RESULTS

The rapid plasma reagin (RPR) seroprevalence was 3.4%. In terms of screening, treatment, and partner notification, the program's performance was adequate. The program's effectiveness was problematic because of false-negative and false-positive RPR results. The cost per averted case was calculated to be US$95 to US$112.

CONCLUSIONS

The sustainability of this labor-intensive program is threatened by costs and logistic constraints. Alternative strategies, such as the mass epidemiologic treatment of pregnant women in high-prevalence areas, should be considered.