Clinical algorithms for the screening of pregnant women for STDs in Libreville, Gabon: which alternatives?

The performance of a syndromic algorithm in diagnosing cervicitis in Jamaica

A cross-sectional survey of 295 persons attending a major sexually transmitted infection clinic in Jamaica's capital city showed that the Ministry of Health's syndromic algorithm has moderate sensitivity and negative predictive value for diagnosing cervicitis. In the absence of diagnostic tests for sexually transmitted infections, a syndromic algorithm continues to be useful for diagnosing sexually transmitted infections.

A paperfluidic platform to detect Neisseria gonorrhoeae in clinical samples

Globally, the microbe Neisseria gonorrhoeae (NG) causes 106 million newly documented sexually transmitted infections each year. Once appropriately diagnosed, NG infections can be readily treated with antibiotics, but high-risk patients often do not return to the clinic for treatment if results are not provided at the point of care. A rapid, sensitive molecular diagnostic would help increase NG treatment and reduce the prevalence of this sexually transmitted disease. Here, we report on the design and development of a rapid, highly sensitive, paperfluidic device for point-of-care diagnosis of NG. The device integrates patient swab sample lysis, nucleic acid extraction, thermophilic helicase-dependent amplification (tHDA), an internal amplification control (NGIC), and visual lateral flow detection within an 80 min run time. Limits of NG detection for the NG/NGIC multiplex tHDA assay were determined within the device, and clinical performance was validated retroactively against qPCR-quantified patient samples in a proof-of-concept study. This paperfluidic diagnostic has a clinically relevant limit of detection of 500 NG cells per device with analytical sensitivity down to 10 NG cells per device. In triplicate testing of 40 total urethral and vaginal swab samples, the device had 95% overall sensitivity and 100% specificity, approaching current laboratory-based molecular NG diagnostics. This diagnostic platform could increase access to accurate NG diagnoses to those most in need.

Chlamydia trachomatis Infection in Pregnancy: The Global Challenge of Preventing Adverse Pregnancy and Infant Outcomes in Sub-Saharan Africa and Asia

Screening and treatment of sexually transmitted infections (STIs) in pregnancy represents an overlooked opportunity to improve the health outcomes of women and infants worldwide. Although Chlamydia trachomatis is the most common treatable bacterial STI, few countries have routine pregnancy screening and treatment programs. We reviewed the current literature surrounding Chlamydia trachomatis in pregnancy, particularly focusing on countries in sub-Saharan Africa and Asia. We discuss possible chlamydial adverse pregnancy and infant health outcomes (miscarriage, stillbirth, ectopic pregnancy, preterm birth, neonatal conjunctivitis, neonatal pneumonia, and other potential effects including HIV perinatal transmission) and review studies of chlamydial screening and treatment in pregnancy, while simultaneously highlighting research from resource-limited countries in sub-Saharan Africa and Asia.

Epidemiology and aetiology of maternal bacterial and viral infections in low- and middle-income countries

BACKGROUND

Maternal morbidity and mortality in low- and middle-income countries has remained exceedingly high. However, information on bacterial and viral maternal infections, which are important contributors to poor pregnancy outcomes, is sparse and poorly characterised. This review aims to describe the epidemiology and aetiology of bacterial and viral maternal infections in low- and middle-income countries.

METHODS

A systematic search of published literature was conducted and data on aetiology and epidemiology of maternal infections was extracted from relevant studies for analysis. Searches were conducted in parallel by two reviewers (using OVID) in the following databases: Medline (1950 to 2010), EMBASE (1980 to 2010) and Global Health (1973 to 2010).

RESULTS

Data from 158 relevant studies was used to characterise the epidemiology of the 10 most extensively reported maternal infections with the following median prevalence rates: Treponema pallidum (2.6%), Neisseria gonorrhoeae (1.5%), Chlamydia trachomatis (5.8%), Group B Streptococcus (8.6%), bacterial vaginosis (20.9%), hepatitis B virus (4.3%), hepatitis C virus (1.4%), Cytomegalovirus (95.7% past infection), Rubella (8.9% susceptible) and Herpes simplex (20.7%). Large variations in the prevalence of these infections between countries and regions were noted.

CONCLUSION

This review confirms the suspected high prevalence of maternal bacterial and viral infections and identifies particular diseases and regions requiring urgent attention in public health policy planning, setting research priorities and donor funding towards reducing maternal morbidity and mortality in low- and middle-income countries.

Prevalence of sexually transmitted infections among antenatal women in Vanuatu, 1999-2000

BACKGROUND

The epidemiology of sexually transmitted infections (STIs) and HIV in Vanuatu is poorly defined.

GOAL

The goal was to determine the prevalence of laboratory-confirmed gonorrhea, chlamydia, trichomoniasis, syphilis seroreactivity, and HIV among pregnant women in Vila, Vanuatu.

STUDY DESIGN

A cross-sectional survey of 547 pregnant women attending a first-visit antenatal hospital clinic in Vila. Laboratory testing included polymerase chain reaction on tampons for chlamydia, gonorrhea, and trichomoniasis; testing of sera for syphilis with rapid plasmid reagin; and enzyme-linked immunosorbent assay for HIV.

RESULTS

The prevalence of trichomoniasis was 27.5% (150); of chlamydia, 21.5% (117); of gonorrhea, 5.9% (32); and of syphilis, 13 (2.4%). No HIV cases were detected; 214 women (40%) had > or =1 STI. Young age and single marital status were both significantly associated with infection (P < 0.001).

CONCLUSION

Chlamydial infection and trichomoniasis are hyperendemic among pregnant women in Vila. Young, single women are at greatest risk for infection.

Prevalence of gonococcal and chlamydial infections and sexual risk behavior among youth in Addis Ababa, Ethiopia

BACKGROUND

No community-based study on the magnitude of sexually transmitted diseases (STDs) has ever been conducted among young people in Ethiopia.

GOAL

To assess the magnitude of Chlamydia trachomatis and Neisseria gonorrhoeae infections and status of sexual risk behavior among youths (15-24 years old) in Addis Ababa, Ethiopia.

STUDY DESIGN

Youths in or out of school residing in two (of the six) administrative zones in Addis Ababa served as the study population. Participants filled out a self-administered questionnaire related to sexuality and its sociocultural determinants. First-void urine (FVU) was analyzed for gonorrhea and chlamydial infection by polymerase chain reaction (PCR).

RESULTS

A total of 561 youths took part in the study. Urine PCR was performed for 522 of them. Nine subjects (1.7%) were found to have and N gonorrhoeae and C trachomatis infections. There were five cases (1.0%) involving each agent. Double infection was noted in one female subject. All but one of the infections were detected among the out-of-school youths (chi-square = 4.5; < 0.05). None of these subjects complained of symptoms suggestive of an active STD. One-third (188/561) reported having had sexual intercourse. The prevalence among sexually active youths was thus 4.8% (9/188) for both infections combined (2.7% for each agent). While 7/52 (13.5%) of the sexually active females were found to also have STDs, only 2/136 (1.5%) of the males had an STD (chi-square = 8.0; < 0.01). Report of sexual activity was significantly associated with being male, an age of >/=20 years, out-of-school status, and report of alcohol/khat (amphetamine-like substance) consumption. Females reported less condom use, whether they were in or out of school and independent of age.

CONCLUSIONS

Out-of-school youths, especially females, took more sexual risk and were exceedingly susceptible to STDs. This calls for alternative group-targeted strategies for sex education, disease prevention, and STD screening and management.

How effective is syndromic management of STDs?: A review of current studies

BACKGROUND

Studies of the accuracy of syndromic management have demonstrated widely varying results depending upon gender, location of infection, risk group, organisms, among other factors.

GOAL

To review current knowledge about syndromic management of sexually transmitted diseases (STDs) and to make recommendations about the strengths and weaknesses of different syndromic management algorithms.

STUDY DESIGN

The authors identified articles and abstracts about the syndromic management of STDs. Evaluation of the effectiveness of algorithms for urethral discharge, genital ulcer disease, and vaginal discharge was based primarily on published sensitivity and specificity data.

RESULTS

Overall, algorithms for the diagnosis and treatment of urethral discharge and genital ulcer disease in men had high sensitivities or cure rates (urethral discharge, 87-99%; genital ulcer disease, 68-98%). The sensitivities for the algorithms for vaginal discharge ranged from 73% to 93% among women presenting with symptoms of vaginal discharge, and from 29% to 86% among women not presenting with symptoms. Vaginal discharge was not found to be an effective indicator of cervical infection and, therefore, is not an independently effective screening tool to detect women with cervical infection, especially in low-risk or asymptomatic populations. Incorporating risk scores can improve the accuracy of algorithms to detect cervical infection.

CONCLUSIONS

Algorithms for urethral discharge and genital ulcer disease can be effective in STDs. The current algorithms for vaginal discharge are not highly effective in detecting gonorrhea and chlamydia in women; risk scores can improve their efficacy, but must be tailored to reflect community risks. Without attention to the qualitative aspects of STD syndromic management, these methods will likely have even less accuracy than the studies reviewed above. There remains an urgent need for the development of an affordable, rapid, and effective diagnostic technique that will improve STD detection in resource-poor settings.

The use of epidemiologic mass treatment and syndrome management for sexually transmitted disease control

BACKGROUND

Epidemiologic mass treatment and syndrome management are two sexually transmitted disease (STD) control strategies that are receiving increased attention internationally. The former is a population-based intervention, whereas the latter attempts to improve the quality and efficiency of clinic-based STD case management.

METHODS

The published literature on these subjects was reviewed.

RESULTS

Epidemiologic mass treatment refers to treatment of whole communities (mass treatment) or high-risk subgroups within communities (targeted presumptive treatment) based on high STD prevalence rates. Syndrome management overcomes many obstacles to provision of quality STD case management by basing treatment decisions on recognition of easily identifiable syndromes. Experience with application of these strategies is summarized, and their possible use as STD control measures in communities with similar conditions is discussed.

CONCLUSIONS

Epidemiologic mass treatment may be an effective approach to rapidly reduce STD transmission in high prevalence communities, especially when high-risk core groups are effectively reached. Once high prevalence rates are brought down, however, longer term strategies, including improved STD case management, are essential to maintain reduced rates.