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

Performance of Syphilis Sentinel Surveillance in the context of endemic Treponematoses: experience from Ghana

Background

Use of treponemal tests to screen for syphilis (caused by Treponema pallidum pallidum) poses challenges with infection status classification, especially in settings where other treponemal infections are endemic. This study aimed to determine the validity of the syphilis surveillance testing strategy implemented since 2004 using two treponemal tests, and estimate the seroprevalence of active syphilis infection in Ghana where yaws (caused by Treponema pallidum pertenue) is endemic.

Methods

We retested sera from the 2007 HIV sentinel survey (HSS) using a traditional algorithm, quantitative rapid plasma reagin test followed by qualitative Treponema pallidum haemagglutination assay. The adjusted seroprevalence of active syphilis was calculated by applying the proportions of active syphilis within identified categories of HSS samples during the retesting, to the entire population of HSS samples. The 95% confidence intervals (CIs) were calculated for each proportion, and the t-test was used to assess differences in proportions.

Results

Of 2,214 samples that were retested, 203 (9.2%) had active syphilis infection, 21 (0.9%) were biological false reactions, 640 (28.9%) were past or treated syphilis infections, and 1,350 (61%) were uninfected. The current syphilis testing strategy overestimated the seroprevalence of active syphilis infection by a third (HSS versus traditional algorithm: 6.0% (95% CI: 5.6–6.3) vs. 4.5% (95% CI: 4.2–4.8); p < 0.001), and had low positive predictive value (16.8%) for detecting active syphilis infection. More than half (51.9%) of HSS syphilis positive cases were actually past/treated treponemal infections, possibly previous exposure to yaws.

Conclusion

There is an urgent need to review the current syphilis sentinel surveillance testing strategy in Ghana in the context of concurrent endemic treponematoses, to better inform policy.

Sexual and reproductive health of micronesians: a systematic review of the literature

INTRODUCTION

Recent evidence of negative sexual and reproductive health (SRH) outcomes for Micronesian migrants warrants a review of what is currently known about Micronesian SRH beliefs, customs, behaviors, outcomes, and access to SRH services.

METHODS

A systematic literature review employing the matrix method was conducted using the same key terms for 8 databases. Peer-reviewed articles published between 1990 and 2010 were abstracted for several key components, including topics, methodology, and other important elements necessary to assess major findings, strengths, and weaknesses.

RESULTS

Thirty-two articles matched the inclusion criteria for review. Of these articles, the major research of interest was behavior relating to sexual risk behavior, pregnancy, health care seeking, and HIV/AIDS for various populations throughout Micronesia. Study populations ranged from pregnant women seeking prenatal care to students in high school.

CONCLUSION

No cohesive body of SRH literature exists for one topic or one community within Micronesia to date.

Yaws in the Western pacific region: a review of the literature

Until the middle of the 20th century, yaws was highly endemic and considered a serious public health problem in the Western Pacific Region (WPR), leading to intensive control efforts in the 1950s–1960s. Since then, little attention has been paid to its reemergence. Its current burden is unknown. This paper presents the results of an extensive literature review, focusing on yaws in the South Pacific. Available records suggest that the region remains largely free of yaws except for Papua New Guinea, Solomon Islands, and Vanuatu. Many clinical cases reported recently were described as “attenuated”; advanced stages are rare. A single intramuscular injection of benzathine penicillin is still effective in curing yaws. In the Pacific, yaws may be amenable to elimination if adequate resources are provided and political commitment revived. A mapping of yaws prevalence in PNG, Solomon, and Vanuatu is needed before comprehensive country-tailored strategies towards yaws elimination can be developed.

Laboratory diagnosis and interpretation of tests for syphilis

The lack of a method for demonstrating the presence of Treponema pallidum by growth necessitates the use of alternative methods. Traditionally, these methods are divided into direct detection methods (animal inoculation, dark-field microscopy, etc.) and serologic tests for the presence of patient antibody against T. pallidum. Serologic methods are further divided into two classes. One class, the nontreponemal tests, detects antibodies to lipoidal antigens present in either the host or T. pallidum; examples are the Venereal Disease Research Laboratory and rapid plasma reagin and tests. Reactivity in these tests generally indicates host tissue damage that may not be specific for syphilis. Because these tests are easy and inexpensive to perform, they are commonly used for screening, and with proper clinical signs they are suggestive of syphilis. The other class of test, the treponemal tests, uses specific treponemal antigens. Confirmation of infection requires a reactive treponemal test. Examples of the treponemal tests are the microhemagglutination assay for antibodies to T. pallidum and the fluorescent treponemal antibody absorption test. These tests are more expensive and complicated to perform than the nontreponemal tests. On the horizon are a number of direct antigen, enzyme-linked immunosorbent assay, and PCR techniques. Several of these techniques have shown promise in clinical trials for the diagnosis of congenital syphilis and neurosyphilis that are presently difficult to diagnose.

Nonvenereal treponematoses: yaws, endemic syphilis, and pinta

The nonvenereal treponematoses--yaws, endemic syphilis, and pinta--constitute a major health concern for many third world countries. These diseases are caused by an organism that is morphologically and antigenically identical to the causative agent of venereal syphilis, Treponema pallidum. Nonvenereal treponematoses differ significantly in their modes of transmission, epidemiology, and clinical presentation from venereal syphilis. Like venereal syphilis, they have a chronic relapsing course and have prominent cutaneous manifestations. Recently, several cases of imported yaws and endemic syphilis have been described in Europe. With the escalating U.S. military presence in many remote areas of the world and ever-increasing world-wide travel, the diagnosis of the nonvenereal treponematoses must be considered in appropriate clinical and historical situations.