Evaluation of the Biostar Chlamydia OIA assay with specimens from women attending a sexually transmitted disease clinic

Rapid point of care test for detecting urogenital Chlamydia trachomatis infection in nonpregnant women and men at reproductive age

BACKGROUND

Chlamydia trachomatis (C trachomatis) is one of the most frequent sexually transmitted infections and a source of deleterious effects on the reproductive health of men and women. Because this infection is likely asymptomatic and is associated with subfertility, ectopic pregnancy, and chronic pain, its presence needs to be confirmed. Technologies available for the diagnosis of C trachomatis infection can be classified into tests performed in a laboratory and rapid tests at the point of care (POC tests). Laboratory-based tests include culture, nucleic acid amplification tests, enzyme immunoassays (EIA), direct fluorescent antibody, nucleic acid hybridization, and transformation tests. Rapid tests include solid-phase EIA and solid-phase optical immunoassay. POC tests can be performed within 30 minutes without the need for expensive or sophisticated equipment. The principal advantage of this technology is the immediate presentation of results with the subsequent possibility to start the treatment of infected patients immediately.

OBJECTIVES

To determine the diagnostic accuracy of rapid point-of-care (POC) testing for detecting urogenital C trachomatis infection in nonpregnant women and men of reproductive age, as verified with nucleic acid amplification tests (NAATs) as the reference standard.

SEARCH METHODS

In November 2019 we searched CENTRAL, MEDLINE, Embase and LILACS. We also searched Web of Science, two trials registries and an abstract database. We screened reference lists of included studies for additional references.

SELECTION CRITERIA

We included diagnostic accuracy studies of symptomatic or asymptomatic nonpregnant women and men reproductive age. Included trials should have prospectively enrolled participants without previous diagnostic testing, co-infections or complications and consecutively or through random sampling at primary or secondary care facilities. Only studies reporting that all participants received the index test and the reference standard and presenting 2 x 2 data were eligible for inclusion. We excluded diagnostic case-control studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Two review authors independently, and in duplicate, assessed eligibility, extracted data, and carried out quality assessment. We resolved differences through consensus or by involving a third review author. We assessed studies for methodological quality using QUADAS-2 and used meta-analysis to combine the results of studies using the bivariate approach to estimate the expected sensitivity and specificity values. We assessed the quality of the evidence using GRADE criteria and explored sources of heterogeneity.

MAIN RESULTS

We included a total of 19 studies, with 13,676 participants, that assessed the diagnostic accuracy of POC tests for C trachomatis infection in nonpregnant women and men of reproductive age, as verified with NAATs as the reference standard. Rapid tests were provided by the distributors in nine studies. Seven studies recruited a predominantly high risk or symptomatic population; the studies were conducted in America, Asia, Africa, Europe and Oceania, with a median prevalence of 10% (range 8% to 28%); nine different brands were assessed. The mean sensitivity for rapid tests for detecting urogenital infection was 0.48 (95% confidence interval (CI) 0.39 to 0.58; low-quality evidence) with a mean specificity of 0.98 (95% CI 0.97 to 0.99; moderate-quality evidence). We explored sources of heterogeneity by looking into differences in diagnostic accuracy according to the specimen (endocervical versus urine or vaginal), symptoms among participants (symptomatic versus asymptomatic), and setting (low/middle-income versus high-income countries). Likelihood ratio tests were not significantly different in terms of sensitivity or specificity by specimen (P = 0.27) or setting (P = 0.28); for this reason, these covariates do not appear to explain the observed variability. Included studies did not provide enough information to assess the 'presence of symptoms' covariate. We downgraded the quality of evidence because of some limitations in applicability and heterogeneity.

AUTHORS' CONCLUSIONS

Based on the results of this systematic review, the POC test based on antigen detection has suboptimal sensitivity but good specificity. Performance of this test translates, on average, to a 52% chance of mistakenly indicating absence of infection and a 2% chance of mistakenly pointing to the presence of this condition. Because of its deleterious consequences for reproductive health, and considering the current availability of safe and effective interventions to treat C trachomatis infection, the POC screening strategy should not be based on a rapid diagnostic test for antigen detection. Research in this topic should focus on different technologies.

Evaluation of Cortez OneStep Chlamydia Rapicard™ Insta Test for the Detection of Chlamydia trachomatis in Pregnant Women at Mbare Polyclinic in Harare, Zimbabwe

BACKGROUND

Cervical chlamydia infection poses high risk of pregnancy complications and neonatal infection. Reference methods for the detection of chlamydia infection are not available for routine use in developing countries. Point-of-care (POC) tests can bridge this gap. This study evaluated Cortez Onestep Chlamydia Rapicard™ insta test for the detection of Chlamydia trachomatis in pregnant women at Mbare Polyclinic and determined the prevalence of C. trachomatis.

METHODS

This was a cross sectional study in 242 pregnant women aged ≥18 years attending their first ANC visit at Mbare polyclinic in Harare, Zimbabwe. Data collection form was used to obtain demographic and predisposing factors to Chlamydia infection and two endocervical swabs were collected from each patient. One specimen was examined by the POC test at the clinic and the other by SDA method in the laboratory.

RESULTS

The sensitivity, specificity, positive and negative predictive values of the rapid kit were 71.4%, 99.6%, 90.9% and 98.3% respectively. Prevalence of C. trachomitis was 5.8% by SDA method.

CONCLUSION AND GLOBAL HEALTH IMPLICATIONS

The kit's sensitivity (71.4%) and specificity (99.6%) implies that the rapid test is an important test which needs further evaluations. The prevalence of C. trichomitis of 5.8% is comparable to studies done elsewhere in Africa.

Diagnostic accuracy of rapid tests for sexually transmitted infections in symptomatic women

OBJECTIVE

To determine the diagnostic accuracy of tests developed for use at the point of care for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and syphilis in women having symptoms of lower urinary tract infection.

METHODS

Cross-sectional study involving sexually active 14-49-year-old women with lower urinary tract infection symptoms consulting during 2010 at a private health clinic and at two public hospitals in Bogotá, Colombia. Pregnant women, those with a previous hysterectomy or those who received antibiotics during the previous 7 days were excluded. Sequential sampling was used; sample size: 1500 women. The ACON NG and CT duo test combo and the ACON individual test plates for NG and separately for CT were used. The QuickVue Chlamydia rapid test (RT) was also used. All of them were compared with nucleic acid amplification methods. The SD Bioline 3.0 and ACON test for syphilis were evaluated and compared with serological tests. Sensitivity and specificity were estimated.

RESULTS

CT RTs had a sensitivity that ranged between 22.7% and 37.7% and specificity between 99.3% and 100%. Sensitivity for NG with ACON Duo was 12.5% and specificity 99.8%. Tests for syphilis had a sensitivity of 91.6-100% and a specificity of 99.7-97.8%.

CONCLUSIONS

The RTs studied are not useful for screening for NG at the point of care. In case of CT a recommendation about their use in routine care should be supported by a cost-effectiveness analysis. In screening populations at high risk of sexually transmitted infections or pregnant women, the RTs for syphilis should be used.

Point of care diagnostics for sexually transmitted infections: perspectives and advances

Accurate and inexpensive point-of-care (POC) tests are urgently needed to control sexually transmitted infection epidemics, so that patients can receive immediate diagnoses and treatment. Current POC assays for Chlamydia trachomatis and Neisseria gonorrhoeae perform inadequately and require better assays. Diagnostics for Trichomonas vaginalis rely on wet preparation, with some notable advances. Serological POC assays for syphilis can impact resource-poor settings, with many assays available, but only one available in the U.S. HIV POC diagnostics demonstrate the best performance, with excellent assays available. There is a rapid assay for HSV lesion detection; but no POC serological assays are available. Despite the inadequacy of POC assays for treatable bacterial infections, application of technological advances offers the promise of advancing POC diagnostics for all sexually transmitted infections.

Molecular Diagnosis of Sexually Transmitted Chlamydia trachomatis in the United States

Chlamydia, with its Chlamydia trachomatis etiology, is the most common bacterial sexually transmitted infection in the United States and is often transmitted via asymptomatic individuals. This review summarizes traditional and molecular-based diagnostic modalities specific to C. trachomatis. Several commercially available, FDA-approved molecular methods to diagnose urogenital C. trachomatis infection include nucleic acid hybridization, signal amplification, polymerase chain reaction, strand displacement amplification, and transcription-mediated amplification. Molecular-based methods are rapid and reliable genital specimen screening measures, especially when applied to areas of high disease prevalence. However, clinical and analytical sensitivity for some commercial systems decreases dramatically when testing urine samples. In vitro experiments and clinical data suggest that transcription-mediated amplification has greater analytical sensitivity than the other molecular-based methods currently available. This difference may be further exhibited in testing of extragenital specimens from at-risk patient demographics. The development of future molecular testing could address conundrums associated with confirmatory testing, medicolegal testing, and test of cure.

What's the Point? How Point-of-Care STI Tests Can Impact Infected Patients

Point-of-care (POC) tests are an important strategy to address the epidemic of sexually transmitted infections (STIs) among both adolescents and young adults. While access to care and confidentiality are major barriers to STI care, POC tests allow the clinician to provide immediate and confidential test results and treatment. In addition, POC test results constitute a "teachable moment"; that is, an opportunity to provide immediate feedback to the patient that may impact his/her risk behaviors. This paper reviews published data and manufacturer's product literature describing current point-of-care STI tests, including studies of test performance as well as impact on treatment intervals and disease spread. It presents theoretical and proposed pitfalls and solutions of implementing POC tests in clinical settings, non-traditional settings, and home care venues. We reviewed the available STI tests according to the World Health Organization (WHO) criteria for judging POC tests: the "ASSURRED" criteria (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, Delivered).

Rapid diagnostic methods in sexually transmitted infections

Sexually transmitted infections (STIs) are common infections throughout the developed and the developing world. It is estimated that worldwide there are 1 million new cases per day of curable bacterial STIs. As part of the World Health Organization 2001 Sexually Transmitted Diseases Diagnostics Initiative, the organization explored the need for simple, affordable, point-of-care STI testing for curable bacterial STIs. This article reviews the evidence supporting the implementation of currently available rapid tests for five common STIs: syphilis, gonorrhea, chlamydia, HIV, and herpes.

Evaluation of the rapid BioStar optical immunoassay for detection of Chlamydia trachomatis in adolescent women

We evaluated the performance of the BioStar Chlamydia OIA (optical immunoassay) in adolescent females (n = 261) from an inner city population. With a reference standard of two different nucleic acid amplification tests, the sensitivity and specificity of the BioStar Chlamydia OIA were 59.4 and 98.4%, respectively. Due to its relatively low sensitivity, the BioStar Chlamydia OIA should only be used in conjunction with more sensitive laboratory tests unless laboratory tests are unavailable or timely return for treatment is unlikely.

New point of care Chlamydia Rapid Test--bridging the gap between diagnosis and treatment: performance evaluation study

OBJECTIVE

To evaluate the performance of a new Chlamydia Rapid Test with vaginal swab specimens as a potential tool for chlamydia diagnosis and screening.

DESIGN

Performance evaluation study. Settings A young people's sexual health centre (site 1) and two genitourinary medicine clinics (sites 2 and 3) in the United Kingdom.

PARTICIPANTS

1349 women aged between 16 and 54 attending one of the three clinics.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value, and negative predictive value of the Chlamydia Rapid Test versus polymerase chain reaction and strand displacement amplification assays; correlation between the Chlamydia Rapid Test visual signal and organism load; acceptability to participants of self collected vaginal swabs as the specimen type for Chlamydia testing.

RESULTS

Polymerase chain reaction positivity rates for Chlamydia trachomatis infection were 8.4% (56/663) at site 1, 9.4% (36/385) at site 2, and 6.0% (18/301) at site 3. Compared with polymerase chain reaction assay, the resolved sensitivity, specificity, positive predictive value, and negative predictive value of the Chlamydia Rapid Test were 83.5% (91/109), 98.9% (1224/1238), 86.7% (91/105), and 98.6% (1224/1242). Compared with strand displacement amplification assay, sensitivity and specificity of the Chlamydia Rapid Test were 81.6% (40/49) and 98.3% (578/588). Organism load of self collected vaginal swabs ranged from 5.97x10(2) to 1.09x10(9) Chlamydia plasmids per swab, which correlated well with the Chlamydia Rapid Test's visual signal (r=0.6435, P<0.0001). Most (95.9%) surveyed participants felt comfortable about collecting their own swabs.

CONCLUSIONS

The performance of the Chlamydia Rapid Test with self collected vaginal swabs indicates that it would be an effective same day diagnostic and screening tool for Chlamydia infection in women. The availability of Chlamydia Rapid Test results within 30 minutes allows for immediate treatment and contact tracing, potentially reducing the risks of persistent infection and onward transmission. It could also provide a simple and reliable alternative to nucleic acid amplification tests in chlamydia screening programmes.

Which test is best for chlamydia?

Nucleic acid amplification tests are now the tests of choice for diagnosing Chlamydia trachomatis infection. For the first time there are diagnostic tests for Chlamydia trachomatis that are more sensitive than tissue culture. Another major advantage is that they can be used with first-catch urine specimens and vaginal swabs. It is thus possible to test for genital chlamydial infection without using invasive specimen collection methods.

Genotyping and haplotyping of CYP2C19 functional alleles on thin-film biosensor chips

OBJECTIVES

Numerous functional polymorphisms in the CYP2C19 gene have been identified; some alleles (e.g. CYP2C19*2 and CYP2C19*3) are associated with poor metabolism of CYP2C19 substrate drugs. Studies have found that the proportion of poor metabolizers, explained by CYP2C19*2 and CYP2C19*3, varies from less than 50% to more than 90% of poor metabolizers. Therefore, phenotype-genotype correlation studies should cover more than CYP2C19*2 and CYP2C19*3. A broader coverage, however, requires an easy-to-use and high-throughput genotyping platform. This broader coverage should also include the recently identified functional allele, CYP2C19*10, which involves a nucleotide change adjacent to the altered nucleotide change in CYP2C19*2. The currently used restriction fragment length polymorphism-based method for genotyping CYP2C19*2 cannot distinguish between CYP2C19*2 and CYP2C19*10. We aim to develop a simple platform that can genotype all CYP2C19 functional alleles.

METHODS

We have developed a thin-film biosensor chip platform to genotype 16 exonic CYP2C19 variants, including two sets of two adjacent single nucleotide polymorphisms and 12 single single nucleotide polymorphisms, using a ligation strategy.

RESULTS

We demonstrate that this is a rapid, accurate, and inexpensive method for genotyping CYP2C19 variants using individual's genomic DNA samples. We further demonstrate that this genotyping platform can be used to construct a haplotype structure of the CYP2C19 variants in a population, and to assign a haplotype combination to each individual on the basis of his/her genotype results.

CONCLUSION

This assay can be applied in pharmacogenomic studies in both basic research and clinical laboratories. It is also an ideal technology for pharmacogenomic tests in both developed and developing countries.

Rapid tests for sexually transmitted diseases

Many molecular diagnostic tests for sexually transmitted diseases (STDs) have been described recently but are not often accessible to clinicians in practice. There is a need for rapid, easy-to-perform, and accurate diagnostic tests for clinicians, especially for use in developing countries, where sophisticated laboratory support is often unavailable. Rapid tests, often termed "point-of-care" (POC) tests, can be performed in less than an hour in the doctor's office, clinic, or in a field setting. If simple laboratory equipment is available, a health care worker or clinician can make an immediate diagnosis of a STD. Progress has been made in the development of POC tests for HIV, syphilis, trichomonas, and bacterial vaginosis, but more work is needed for chlamydia and gonorrhea. Improvements in POCs will allow for faster treatment or provision of interventions in infected persons, in order to prevent transmission to partners or infants, thereby enabling effective control efforts for STDs.

The demographic and behavioural profile of women with cervicitis infected with Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum and the comparison of two medical regimens

OBJECTIVE

The aim of this study was to compare the therapeutic effect of single dose oral azithromycin with twice-daily, 7-day doxycycline in women with chlamydial, mycoplasmic or ureaplasmic cervicitis and to demonstrate the demographic and behavioral profile of infected women.

MATERIALS AND METHODS

Five hundred and thirty-three women with various gynecologic complaints were recruited for this study. All women were screened for Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) by enzyme immune assay tests. Patients positive for Neisseria gonorrhoeae were excluded. Women treated for these infections were tested after completing medical therapy. Educational levels of infected women were similar in each group. The prevalence of CT, UU and MH was 3.4% (18/533), 11.8% (63/533) and 0.9% (5/533), respectively. In 452 patients, no treatment was administered. The remaining patients were either treated with azithromycin (n=41) or doxycycline (n=40). The eradication rate for the infectious agents was 87.3% and 93.5% in the group of azithromycin and doxycycline, respectively (P>0.05). There was no statistically significant difference in efficacy between single dose azithromycin and a 7-day course of doxycycline with respect to the treatment of culture-positive cases. Recurrences were observed in five cases in azithromycin group (12.5%) and in three cases in doxycycline group (7.5%).

CONCLUSIONS

The treatment of uncomplicated chlamydial, mycoplasmic and ureaplasmic cervicitis with a single dose of azithromycin administered under supervision in the clinic is as effective as a 7-day course of doxycycline. This regimen may overcome the problem of compliance with the standard twice-daily, 7-day regimen of doxycycline.

Optical immunoassay for snake venom detection

A sensitive and specific optical immunoassay (OIA) has been developed for snake venom detection. The assay is based on the principle of detection of physical changes in thickness of molecular thin film resulting from specific binding events on an optical silicon chip (SILAS-I, ThermoBioStar, Colorado, USA). The reflection of white light through the thin film results in destructive interference of a particular wavelength of the light from gold to purple-blue depending on the thickness of the thin film formed or the amount of venom in the test sample. A prototype test kit for the simultaneous identification of species and semi-quantitative detection of venoms from four medically important snakes of South Vietnam (Trimeresurus albolabris, Calloselasma rhodostoma, Naja kaouthia and Ophiophagus hannah) has been developed. The kit can detect venom analytes in blood, plasma, urine, wound exudates, blister fluid or tissue homogenates. The efficacy of the test kit in snakebite diagnosis has been demonstrated in experimental envenomations and sample analytes taken from snakebite victims in South Vietnam. This rapid snake venom detection kit based on OIA technique is potentially applicable in the clinics as well as in the field.

Decision analysis: point-of-care Chlamydia testing vs. laboratory-based methods

OBJECTIVE

To evaluate and compare the performance of several different methods available for detection of Chlamydia trachomatis (Ct) infection, and to explore possible testing and treatment strategies incorporating point-of-care testing versus laboratory-based tests.

DESIGN

Prospective trial and decision analysis.

SETTING

Large, urban, publicly funded sexually transmitted disease clinic.

PARTICIPANTS

1,384 female patients.

METHODS

Each subject was tested for Ct infection by direct fluorescent antibody (DFA, Sanofi/Kallestad, Chaska, MN), optical immunoassay (OIA, Thermo Electron, Point of Care and Rapid Diagnostics, Louisville CO), McCoy cell culture (in-house method), and polymerase chain reaction (microwell PCR, microwell assay, Roche, Branchburg NJ).

RESULTS

Performing a rapid in-clinic test on women who did not meet empiric treatment criteria would have increased the overall proportion of infected persons receiving same-day treatment from 48.6% to 79.1% using DFA or 78.4% using OIA.

CONCLUSIONS

Use of empiric treatment criteria and same-day point-of-care testing for patients not meeting the empiric treatment threshold appears to be an appropriate, useful, and cost-effective strategy for increasing same-day treatment of Ct infections in this population.

The accuracy and efficacy of screening tests for Chlamydia trachomatis: a systematic review

Screening women for lower genital tract infection with Chlamydia trachomatis is important in the prevention of pelvic inflammatory disease, ectopic pregnancy and infertility. This systematic review aims to state clearly which of the available diagnostic tests for the detection of C. trachomatis would be most effective in terms of clinical effectiveness. The review included all studies published from 1990 onward that evaluated diagnostic tests in asymptomatic, young, sexually active populations. Medline and Embase were searched electronically and key journals were hand-searched. Further studies were identified through the Internet and contact with experts in the field. All studies were reviewed by two reviewers and were scored by Irwig's assessment criteria. Additional quality assessment criteria included a documented sexual history and recording of previous chlamydial infection. The reviews were subjected to meta-analysis and meta-regression. The 30 studies that were included examined three types of DNA-based test--ligase chain reaction (LCR), PCR and gene probe--as well as enzyme immuno-assay (EIA). The results showed that while specificities were high, sensitivities varied widely across the tests and were also dependent on the specimen tested. Pooled sensitivities for LCR, PCR, gene probe and EIA on urine were 96.5%, 85.6%, 92% and 38%, respectively, while on cervical swabs the corresponding sensitivities of PCR, gene probe and EIA were 88.6%, 84% and 65%. Meta-analysis demonstrated that DNA amplification techniques performed best for both urine and swabs in low prevalence populations. We conclude that nucleic acid amplification tests used on non-invasive samples such as urine are more effective at detecting asymptomatic chlamydial infection than conventional tests, but there are few data to relate a positive result with clinical outcome.

A new avidin-biotin optical immunoassay for the detection of beta-bungarotoxin and application in diagnosis of experimental snake envenomation

A highly sensitive avidin-biotin optical immunoassay (AB-OIA) has been developed for the detection of beta-bungarotoxin (beta-BuTx), a neurotoxin from the venom of Bungarus multicinctus, in whole blood, plasma, and urine. Affinity purified rabbit IgG anti-beta-BuTx antibody was immobilized on an optically active silicon surface (SILIAS wafer). The test sample was incubated and the antigen-antibody reaction was monitored by the addition of a biotinylated monoclonal antibody (mAb 15) specific to the toxin, avidin-horseradish peroxidase (HRP) and tetramethylbenzidine substrate. The silicon assay surface technology enables us to directly visualize a physical change in the optical thickness of the antibody thin film. The change in thickness is due to the specific capture of the toxin on the surface and when the substrate is added, the binding event is amplified, which then alters the reflected light path and a change in colour is visualized. The assay could detect beta-BuTx levels as low as 16 pg/ml in sample buffer and 100 pg/ml in whole blood or plasma. The AB-OIA is simple, requires only 40 microl of biological fluid and can be performed without specialized equipment. The efficacy of the test for detection of beta-BuTx in blood or plasma obtained from mice during experimental envenomation with B. multicinctus venom was demonstrated. The AB-OIA was also used to quantitate the postmortem level of beta-BuTx in various organs such as brain, liver, and kidney, as well as the tissue at the site of injection. Development of a simple, rapid snake toxin detection kit based on AB-OIA technique potentially applicable in the clinics as well as in the field is discussed.

Impact of reference standard sensitivity on accuracy of rapid antigen detection assays and a leukocyte esterase dipstick for diagnosis of Chlamydia trachomatis infection in first-void urine specimens from men

A total of 128 previously frozen first-void urine (FVU) specimens from selected asymptomatic men were centrifuged and tested by three Chlamydia trachomatis rapid antigen detection tests and with a leukocyte esterase (LE) dipstick. When the results were compared to those of a reference standard of positivity determined by the Chlamydiazyme enzyme immunoassay as confirmed by a blocking assay, the sensitivities of the Testpack Chlamydia (Abbott), Clearview Chlamydia (Unipath), and Surecell Chlamydia (Kodak) tests and the LE dipstick test were 76.4, 76.4, 67.3, and 88.6%, respectively. Use of the ligase chain reaction (LCR), whose results were confirmed by direct fluorescent-antibody staining of elementary bodies, as the reference standard reduced the sensitivities to 70.9, 67.7, 62.9, and 87.5%, respectively. The specificities by use of LCR as the reference standard were 95.5, 95.5, 100, and 92.4%, respectively. These rapid chlamydial antigen tests performed reasonably well with FVU specimens, but the simple LE dipstick test, which had the highest sensitivity, would have enabled treatment of the greatest number of infected male patients.

The rapid test paradox: when fewer cases detected lead to more cases treated: a decision analysis of tests for Chlamydia trachomatis

BACKGROUND AND OBJECTIVES

Screening tests for detection of Chlamydia trachomatis include those processed in laboratories and those designed to be processed at the point of care. The latter tests can yield results at the time of the initial patient visit, but most available lab-processed tests have greater sensitivity. In settings where a proportion of patients do not return for treatment after positive test results, the less sensitive rapid tests could lead to the treatment of more patients and be more cost-effective.

GOAL OF THIS STUDY

To determine the situations, if any, in which a rapid test might be more cost-effective and treat more infections than lab-based tests.

STUDY DESIGN

A decision analysis framework was used to compare one point-of-care test (the BioStar Chlamydia OIA) with two lab-based tests (cell culture and the polymerase chain reaction [PCR] assay). It was assumed that all women in the model would be screened. Variables included in the analysis were the prevalence, test sensitivity and specificity, the probability of developing pelvic inflammatory disease after treated and untreated chlamydial infections, and the likelihood that patients would wait for rapid test results or return to the facility for treatment.

RESULTS

The rapid test treated more cases of infection than the PCR alone if the return rate was less than 65%. A two-test algorithm of the rapid test followed by a PCR test on those initially testing negative identified and treated the greatest number of chlamydial infections and was the most cost-effective at all prevalences above 9%, but this finding was sensitive to the cost estimate for pelvic inflammatory disease.

CONCLUSION

In settings where patient return for treatment is a problem, point-of-care tests contribute significantly to the detection and treatment of chlamydial infections among women.