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D Mabey

Publications and source records attributed to D Mabey.

At least 19 recordsLinked to original sources
PubMed2006

Rapid tests for sexually transmitted infections (STIs): the way forward.

In the developing world, laboratory services for sexually transmitted infections (STIs) are either not available, or where limited services are available, patients may not be able to pay for or physically access those services. Despite the existence of national policy for antenatal screening to prevent congenital syphilis and substantial evidence that antenatal screening is cost-effective, implementation of syphilis screening programmes remains unacceptably low because of lack of screening tools that can be used in primary health care settings. The World Health Organization Sexually Transmitted Diseases Diagnostics Initiative (SDI) has developed the ASSURED criteria as a benchmark to decide if tests address disease control needs: Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free and Deliverable to end-users. Rapid syphilis tests that can be used with whole blood approach the ASSURED criteria and can now be deployed in areas where no previous screening has been possible. Although rapid tests for chlamydia and gonorrhoea lack sensitivity, more tests are in development. The way forward for STI diagnostics requires a continuing quest for ASSURED tests, the development of a road map for test introduction, sustainable programmes for quality assurance, and the creation of a robust infrastructure linked to HIV prevention that ensures sustainability of STI control efforts that includes viral STIs.

Chlamydia Infections↗
PubMed2006

Clinic-based evaluation of Clearview Chlamydia MF for detection of Chlamydia trachomatis in vaginal and cervical specimens from women at high risk in China.

OBJECTIVES: To determine the performance of a rapid Chlamydia trachomatis (CT) test (Clearview Chlamydia MF) compared to the current "gold standard" (Roche Amplicor CT assay) test, and to assess acceptability of the tests to patients. METHODS: A total of 1497 women at sexually transmitted diseases (STD) clinics or re-education centres in six urban cities (Shanghai, Nanjing, Shenzhen, Guangzhou, Chengdu and Fuzhou) in China participated in the study. Three vaginal and three cervical swabs were collected from each participant. Rapid CT tests were performed locally on the first vaginal and cervical swabs and the results were read independently by two staff members. The second and third swabs were randomised for performing the Roche CT assay at the National STD Reference Laboratory. Acceptability of the rapid tests to patients was determined by asking patients in clinics about their willingness to wait for the results. RESULTS: The prevalence of CT was 13.2% (197/1497), as determined by the Roche assay with cervical specimens. CT was detected in 78 vaginal and 127 cervical specimens by the rapid test and the positive rates determined with cervical specimens were significantly higher than those with vaginal specimens (p<0.001). There was good agreement between the results read by two independent staff for either vaginal or cervical specimens (both kappa = 0.98, p<0.001). Sensitivities for vaginal and cervical specimens were 32.8% and 49.7%, respectively, and specificities were 99.2% and 97.9%, respectively. The positive predictive value was 85.7% for vaginal and 78.4% for cervical specimens. The vast majority of the patients (99.1%) were willing to wait up to two hours for the results. CONCLUSION: Clearview Chlamydia MF, while yielding a rapid result and requiring minimal laboratory facilities, had unacceptably low sensitivity compared to a nucleic acid amplification test. Rapid tests yielding results within one hour are generally accepted by the clients.

Adult↗
PubMed2006

Diagnosis of gonococcal infection in high risk women using a rapid test.

OBJECTIVE: To assess the performance and acceptability for patients and health care workers of the NGThermo Biostar (GC OIA) to diagnose gonococcal infection compared with culture using modified Thayer Martin medium. METHODS: This study involved 326 high-risk women presenting with vaginal discharge or referral by sexual partner with urethral discharge at a sexually transmitted infections (STI) clinic in Manaus, Brazil. Endocervical swabs collected from the women were tested with both the NG Biostar and modified Thayer Martin culture as the reference standard test. Clinic staff were trained to perform the NG Biostar on site and the culture was performed in the laboratory of the clinic. RESULTS: The prevalence of gonococcal infection as measured by the reference standard was 15% (50/326) overall. Among asymptomatic participants, the prevalence of infection was 17.7% (25/141) and among symptomatic women it was 13.5% (25/185) (p = 0.3). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the NG Biostar test, with 95% confidence intervals (CI), were 60% (46.4% to 73.6%), 89.9% (86.2% to 93.6%), 55.6% (42.4% to 68.8%), and 92.6% (89.5% to 95.7%), respectively; 98.8% of study participants were willing to wait approximately 1 hour in the clinic for test results. CONCLUSION: Syndromic management protocols for treatment of STI in developing countries require refinement because, as currently described, they lead to over-treatment of cervical infection. A rapid test done during patients' initial presentation and leading to immediate treatment if positive would help improve the accuracy of diagnosis and could also be used to screen asymptomatic women. Even though the NG Biostar had a low sensitivity and PPV, which is less than ideal, it could still improve the rates of treatment over the gold standard test that requires return visits for patients to receive results and to benefit from treatment. Cost-effectiveness studies using rapid point-of-care tests for Neisseria gonorrhoeae infection compared to the syndromic approach should be carried out to assess their value in STI diagnosis and treatment in developing nations.

Adolescent↗
PubMed2006

Interventions for trachoma trichiasis.

BACKGROUND: Trachoma is a leading cause of avoidable blindness. The World Health Organization recommends eliminating trachoma blindness by the SAFE strategy incorporating Surgery, Antibiotic treatment, Facial cleanliness and Environmental hygiene. OBJECTIVES: This review examined the evidence for the effectiveness of different interventions for trachoma trichiasis. SEARCH STRATEGY: We identified trials from the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (2005, Issue 3), MEDLINE (1966 to September 2005) PubMed (searched on 21-09-06; last 90 days), EMBASE (1980 to September 2005), LILACS (March 2004) and the reference lists of included studies. We also contacted authors for details of other relevant studies. SELECTION CRITERIA: We included randomised trials of any intervention intended to treat trachoma trichiasis and trials comparing different methods of delivering the same intervention. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials. We contacted trial authors for missing data when necessary. MAIN RESULTS: Seven studies met the inclusion criteria. Three studies compared different surgical interventions. These trials suggest the most effective surgery is full-thickness incision of the tarsal plate and rotation of the terminal tarsal strip 180 degrees. One study showed that bilamellar rotation was more effective than unilamellar rotation but the other two studies did not. One trial found double-sided sticking plaster more effective than epilation for the immediate management of trichiasis but required frequent replacement (odds ratio (OR) 0.01, 95% confidence interval (CI) 0.00 to 0.22). Another trial found community-based surgery increased convenience for patients without increasing the risk of complications or recurrence when compared to health centres. One trial found no difference between trichiasis surgery performed by ophthalmologists and integrated eye workers (OR 1.32, 95% CI 0.83 to 2.11). A trial comparing trichiasis surgery with and without concurrent administration of azithromycin found no difference in success rates at one year (OR 0.99, 95% CI 0.67 to 1.46). AUTHORS' CONCLUSIONS: No trials show interventions for trichiasis prevent blindness. Certain interventions have been shown to be more effective at eliminating trichiasis. Full thickness incision of the tarsal plate and rotation of the lash-bearing lid margin through 180 degrees is probably the best technique and is preferably delivered in the community. The use of double-sided sticking plaster is more effective than epilation as a temporary measure. Surgery may be carried out by an ophthalmologist or a trained ophthalmic assistant. The addition of azithromycin treatment at the time of surgery does not appear to improve outcomes.

Anti-Bacterial Agents↗
PubMed2006

Lack of evidence for the involvement of rectal and oral trichomonads in the aetiology of vaginal trichomoniasis in Ghana.

OBJECTIVE: To investigate the possible involvement of human trichomonads (Pentatrichomonas hominis and Trichomonas tenax) other than Trichomonas vaginalis in the aetiology of vaginal trichomoniasis. METHODS: Vaginal swabs taken from women attending antenatal clinics were tested for Trichomonas vaginalis by traditional assays (wet-mount microscopy and InPouch culture) and nucleic acid amplification (polymerase chain reaction). These swabs were also tested for the presence of P hominis and T tenax by nucleic acid amplification. Oral and rectal swabs from these women were tested for T tenax and P hominis respectively. Data on sociodemographic characteristics, sexual and anogenital hygiene practices likely to seed P hominis and T tenax into the vagina were collected by a questionnaire. RESULTS: 93% (161) of the 173 samples in which T vaginalis was detected by wet preparation or culture was evaluable by PCR. Of this, T vaginalis was detected in 94% (152) by T vaginalis-specific PCR. Neither P hominis nor T tenax was detected in any of the vaginal swab samples. These included nine samples for which T vaginalis had been detected by wet preparation or culture, but were negative by T vaginalis nucleic acid amplification. P hominis and T tenax were not detected in any of the rectal and oral swabs, respectively. CONCLUSION: In this group of women, there was no evidence for the involvement of trichomonads other than T vaginalis in the aetiology of vaginal trichomoniasis.

Adolescent↗
PubMed2006

Lack of effectiveness of syndromic management in targeting vaginal infections in pregnancy in Entebbe, Uganda.

OBJECTIVES: To measure the prevalence of reproductive tract infections (RTIs) during pregnancy in Entebbe, Uganda, and to evaluate the current syndromic diagnosis and management approach in effectively targeting infections, such as bacterial vaginosis (BV) and trichomoniasis, that are associated with low birth weight and prematurity among newborns. METHODS: We enrolled 250 antenatal clinic attenders. Vaginal swabs and diagnostic tests were performed for BV, Trichomonas vaginalis (TV), candida, Neisseria gonorrhoeae, Chlamydia trachomatis and for HIV-1 and active (TPHA+/RPR+) syphilis infection. Same day treatment was offered for symptoms according to syndromic management guidelines. The treatment actually provided by healthcare workers was documented. Sensitivity, specificity, positive and negative predictive values were used to assess the effectiveness of syndromic management guidelines and practice. RESULTS: The prevalence of infections were: BV 47.7%, TV 17.3%, candida 60.6%, gonorrhoea 4.3%, chlamydia 5.9%, syphilis 1.6%, and HIV 13.1%. In total, 39.7% of women with BV and 30.2% of those with TV were asymptomatic. The sensitivity of syndromic management as applied by health workers in targeting BV and TV was 50.0% and 66.7%, respectively. This would have increased to 60.3% (BV) and 69.8% (TV) had the algorithm been followed exactly. CONCLUSIONS: The prevalence of BV and TV seen in this and other African populations is high. High rates of asymptomatic infection and a tendency of healthcare workers to deviate from management guidelines by following their own personal clinical judgment imply that many vaginal infections remain untreated. Alternative strategies, such as presumptive treatment of BV and TV in pregnancy, should be considered.

Adolescent↗
PubMed2006

The burden and determinants of reproductive tract infections in India: a population based study of women in Goa, India.

BACKGROUND/OBJECTIVE: Reproductive tract infections (RTI) present major health, social, and economic problems in developing countries. Our objective was to describe the prevalence and risk factors of RTIs in a population based sample of women aged 18-45 years. METHOD: 2494 women of 3000 randomly selected from the population defined by a primary health centre catchment area consented to participate. Participants were interviewed regarding complaints and risk factors. Laboratory specimens were collected for the diagnosis of RTIs. Analyses of risk factors were carried out separately for the outcomes of sexually transmitted infections: chlamydia, gonorrhoea, trichomoniasis; and endogenous infections: bacterial vaginosis (BV) and candida. RESULTS: Endogenous infections were relatively common (BV 17.8%; candida 8.5%), and sexually transmitted infections (STI) were infrequent (4.2%). Factors indicative of poverty and marginalisation were associated with STIs and BV. Gender disadvantage, particularly spousal violence, was associated with BV, while concern about a husband's extramarital relationships, an indicator of sexual risk, was associated with STI. Husband's discharge was strongly associated with STI, and a non-white vaginal discharge was associated with both STI and BV. Condom use and oral contraceptive use were associated with a reduced risk of BV. CONCLUSIONS: Most of the population burden of RTIs is attributed to endogenous infections. Socioeconomic deprivation and gender disadvantage are associated with raised risk for BV, while the risk factors for STIs indicated that disadvantaged women were likely to be infected by their husbands.

Adolescent↗
PubMed2006

Modelling the cost effectiveness of rapid point of care diagnostic tests for the control of HIV and other sexually transmitted infections among female sex workers.

BACKGROUND: In sub-Saharan Africa, gonococcal and chlamydial infections are usually managed using the syndromic approach. However, many infections are asymptomatic in women, and the syndromic algorithm has poor sensitivity and specificity for infections caused by Neisseria gonorrhoeae (Ng) and Chlamydia trachomatis (Ct). Because of this, rapid point of care (POC) tests for Ct/Ng could improve sexually transmitted infection (STI) management in women. This study uses mathematical modelling to estimate the incremental cost effectiveness of using POC tests to diagnose Ng/Ct instead of the current syndromic approach used by the SIDA2 HIV/STI prevention project for female sex workers in Cotonou, Benin. METHODS: A dynamic mathematical model was used with data from Cotonou to estimate the HIV impact of the existing SIDA2 project (1995-8), and to project how impact would change if POC tests had been used. As observed in test evaluations, the POC tests were assumed to have high specificity, but a range of sensitivities. The incremental economic cost effectiveness of using POC tests was modelled using data on intervention costs and an evaluation of an Ng POC test in Cotonou in 2004. All costs were in 2004 US dollars. RESULTS: The model estimated the STI treatment aspect of the intervention averted 18 553 Ng/Ct and 359 HIV infections over 4 years when the syndromic approach was used. In contrast, if Ng/Ct had been diagnosed with a 70-80% sensitive and 95% specific POC test then 24-31% fewer clinic attenders would have been treated, 40-60% more Ng/Ct and HIV infections would have been averted, and the incremental cost effectiveness of using them would have been 107-151 dollars per HIV infection averted if the POC tests cost 2 dollars and 58-81 dollars if they cost 1 dollar. CONCLUSIONS: POC tests can be a cost effective strategy for substantially increasing the impact on HIV transmission, and decreasing the degree of inappropriate treatment of STI treatment interventions that use syndromic management to diagnose Ng/Ct.

Benin↗
PubMed2006

Modelling the cost-effectiveness of introducing rapid syphilis tests into an antenatal syphilis screening programme in Mwanza, Tanzania.

OBJECTIVES: A study found screening (with rapid plasma reagin (RPR)) pregnant women for maternal syphilis was cost-effective in Mwanza, Tanzania. Recently, four rapid point-of-care (POC) syphilis tests were evaluated in Mwanza, and found to have reasonable sensitivity/specificity. This analysis estimates the relative cost-effectiveness of using these POC tests in the Mwanza syphilis screening intervention. METHODS: Empirical cost and epidemiological data were used to model the potential benefit of using POC tests instead of RPR. Reductions in costs relating to training, supplies, and equipment were estimated, and any changes in impact due to test sensitivity were included. Additional modelling explored how the results vary with prevalence of past infection, misclassified RPR results, and if not all women return for treatment. RESULTS: The cost-effectiveness of using POC tests is mainly dependent on their cost and sensitivity for high titre active syphilis (HTAS). Savings due to reductions in training and equipment are small. Current POC tests may save more disability-adjusted life years (DALYs) than the RPR test in Mwanza, but the test cost needs to be <0.63 US dollars to be as cost-effective as RPR. However, the cost-effectiveness of the RPR test worsens by 15% if its HTAS sensitivity had been 75% instead of 86%, and by 25-65% if 20-40% of women had not returned for treatment. In such settings, POC tests could improve cost-effectiveness. Lastly, the cost-effectiveness of POC tests is affected little by the prevalence of syphilis, false RPR-positives, and past infections. DISCUSSION: Although the price of most POC tests needs to be reduced to make them as cost-effective as RPR, their simplicity and limited requirements for electricity/equipment suggest their use could improve the coverage of antenatal syphilis screening in developing countries.

Cost-Benefit Analysis↗
PubMed2006

Prospective, multi-centre clinic-based evaluation of four rapid diagnostic tests for syphilis.

OBJECTIVES: To evaluate prospectively four rapid, point-of-care serological tests for syphilis in prenatal or high risk populations in four countries. METHODS: Tests were performed on consecutive clinic attenders, using whole blood in the clinic, and whole blood and serum in the laboratory. The sensitivity and specificity of each test was evaluated, using a standard treponemal test (Treponema pallidum haemagglutination assay (TPHA) or fluorescent treponemal antibody, absorbed (FTA-ABS) as gold standard. Non-treponemal tests (rapid plasma reagin (RPR) or venereal diseases research laboratory (VDRL) tests) were also performed on all subjects at three sites. RESULTS: The specificity of each rapid test was >95% at each site. Sensitivities varied from 64-100% and, in most cases, were lower when whole blood was used rather than serum. CONCLUSIONS: Rapid serological tests for syphilis are an acceptable alternative to conventional laboratory tests. Since they do not require equipment or electricity, they could increase coverage of syphilis screening, and enable treatment to be given at the first clinic visit.

Adolescent↗
PubMed2005

Antibiotics for trachoma.

BACKGROUND: Trachoma is the world's leading cause of preventable blindness. In 1997 the World Health Organization launched an initiative on trachoma control based on the 'SAFE' strategy (surgery, antibiotics, facial cleanliness and environmental improvement). OBJECTIVES: To assess the evidence supporting the antibiotic arm of the SAFE strategy by assessing the effects of antibiotics on both active trachoma (primary objective) and on Chlamydia trachomatis infection of the conjunctiva (secondary objective). SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library Issue 1, 2005), MEDLINE (1966 to February 2005), and EMBASE (1980 to February 2005). We used the Science Citation Index to look for articles that cited the included studies. We searched the reference lists of identified articles and we contacted authors and experts for details of further relevant studies. SELECTION CRITERIA: We included only randomised trials that satisfied either of two criteria: (a) trials in which topical or oral administration of an antibiotic was compared to placebo or no treatment in people with trachoma, (b) trials in which a topical antibiotic was compared with an oral antibiotic in people with trachoma. A subdivision of particular interest was of trials in which topical tetracycline/chlortetracycline was compared with oral azithromycin, as these are the two World Health Organization recommended treatments. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted investigators for missing data. MAIN RESULTS: We found 15 studies that randomised a total of 8678 participants. For both outcomes (active trachoma and laboratory evidence of infection) the results of the chi squared tests suggested that there was significant statistical heterogeneity among the trials. There was also marked clinical heterogeneity. No summary statistics were calculated and we therefore present a narrative summary of the results. For the comparisons of oral or topical antibiotic against placebo/no treatment, the data are consistent with there being no effect of antibiotics but are suggestive of a lowering of the point prevalence of relative risk of both active disease and laboratory evidence of infection at three and 12 months after treatment. For the comparison of oral against topical antibiotics the results suggest that oral treatment is neither more nor less effective than topical treatment. AUTHORS' CONCLUSIONS: There is some evidence that antibiotics reduce active trachoma but results are not consistent and cannot be pooled.

Administration, Oral↗
PubMed2005

Sexually transmitted infections in pregnancy: prevalence, impact on pregnancy outcomes, and approach to treatment in developing countries.

Sexually transmitted infections (STIs) are common in the developing world. Management of STIs in pregnancy in many developing countries has, however, been complicated by the lack of simple and affordable diagnostic tests. This review examines the prevalence and impact on pregnancy outcome of STIs in developing countries and recommends approaches to management of STIs in pregnancy for resource poor settings.

Anti-Bacterial Agents↗
PubMed2004

Approaches to the control of sexually transmitted infections in developing countries: old problems and modern challenges.

Sexually transmitted infections (STIs) constitute a huge health and economic burden for developing countries: 75-85% of the estimated 340 million annual new cases of curable STIs occur in these countries, and STIs account for 17% economic losses because of ill health. The importance of STIs has been more widely recognised since the advent of the HIV/AIDS epidemic, and there is good evidence that the control of STIs can reduce HIV transmission. The main interventions which could reduce the incidence and prevalence of STIs include primary prevention (information, education and communication campaigns, condom promotion, use of safe microbicides, and vaccines), screening and case finding among vulnerable groups (for example, pregnant women), STI case management using the syndromic approach, targeted interventions for populations at high risk (for example, sex workers), and in some circumstances (targeted) periodic mass treatment. The challenge is not just to develop new interventions, but to identify barriers to the implementation of existing tools, and to devise strategies for ensuring that effective STI control programmes are implemented in the future.

Adolescent↗
PubMed2004

Comparison of latex agglutination, wet preparation, and culture for the detection of Trichomonas vaginalis.

OBJECTIVES: To compare the performance of three diagnostic methods for Trichomonas vaginalis infection-latex agglutination, saline wet mount, and culture. METHODS: Vaginal swabs from 3807 women attending antenatal clinics were tested for the presence of T vaginalis by latex agglutination. All positives and the following two negatives were tested by wet preparation and culture. RESULTS: The prevalence of infection by latex agglutination was 5.4%. Using an expanded gold standard based on the wet mount and culture results, the sensitivity of the latex agglutination test was 98.8% (95% CI 95.9 to 99.9) and specificity was 92.1 (89.2 to 94.5). The kappa index for test agreement was 0.93 for latex and culture and 0.88 for latex and wet preparation. CONCLUSION: The latex agglutination test is a highly sensitive test for detecting T vaginalis infection. It is a simple rapid test and has the potential for use in screening and diagnostic settings.

Animals↗
PubMed2003

The reliability of a structured examination protocol and self administered vaginal swabs: a pilot study of gynaecological outpatients in Goa, India.

OBJECTIVES: Low participation rates for gynaecological examination and low reliability of clinical reporting of gynaecological examination findings are problems in community studies of gynaecological morbidity in India. This pilot study aimed to describe the reliability of a new examination protocol for recording the findings of gynaecological examination and the reliability and acceptability of the use of self administered vaginal swabs for the diagnosis of reproductive tract infections. METHOD: 75 women attending a gynaecology outpatient clinic were purposively sampled. Each woman was examined by two gynaecologists independently who recorded findings on the new examination protocol. Two swabs were collected from each woman, one by the gynaecologist and one by the woman. Swabs were smeared on separate slides which were stained and read for bacterial vaginosis and candidiasis by laboratory technicians blind to the mode of collection of the slides. RESULTS: The study showed a high inter-rater reliability for most of the items of the examination protocol. The interslide agreement for the diagnosis of the two RTIs was high. One third of women preferred the self administered swab. CONCLUSIONS: The examination protocol is a reliable method of recording gynaecological examination findings, and self administered swabs a useful way of obtaining vaginal specimens from women who did not wish to undergo gynaecological examinations in studies in the Indian setting.

Adolescent↗
PubMed2003

Sensitivity requirements for the point of care diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae in women.

BACKGROUND/OBJECTIVES: Most current tests for Neisseria gonorrhoeae and Chlmydia trachomatis require the support of a laboratory, and results are not usually available before the patient has left the clinic. This delay can lead to patients not returning for treatment and may allow further STI transmission to occur. Current rapid point of care (POC) STI tests and the syndromic approach are less sensitive than gold standard tests, but allow treatment at the initial visit. This study estimates the required sensitivity of POC tests that ensures as many STIs are averted as with current gold standard tests. METHODS: A mathematical model is developed to compare the STIs averted using different STI diagnostic methods. Data from Benin, South Africa, Tanzania, and England are used to explore how the required sensitivity differs between settings. RESULTS: The required sensitivity of a POC test is low if there is significant STI transmission during the delay in treatment for the gold standard test and/or few women return for treatment. For example, the required sensitivity of a POC test for C trachomatis is 50% (gold standard test sensitivity is 90%) if either 55% return for treatment and there is no STI transmission, or 80% return for treatment and 50% of infected women infect their partner during the delay in treatment. Furthermore, in these settings a POC test of moderate sensitivity can lead to significantly more STI averted than the gold standard test. CONCLUSIONS: These results support the use of moderate sensitivity POC tests in scenarios where many women will not return for treatment, and in populations where the delay in treatment would result in significant STI transmission.

Benin↗