The SOS-SAH questionnaire in clinical practice: a multi-method evaluation study.

BACKGROUND: In patients with mild disabilities after aneurysmal subarachnoid hemorrhage (aSAH), invisible symptoms might be easily overlooked during consultations in the outpatient clinic. We hypothesize that the Questionnaire for the Screening of Symptoms in aneurysmal Subarachnoid Hemorrhage (SOS-SAH), a disease-specific patient-reported outcome measure, might aid in screening for symptoms after aSAH. The objective of this explorative study is to evaluate the perceived impact of using the SOS-SAH in daily clinical practice for patients after aSAH, as well as to explore potential barriers to further implementation. METHODS: This multi-method study consists of a quantitative and a qualitative component. To evaluate differences in quality of care, a patient experience survey was sent to patients receiving usual care and to patients who received the SOS-SAH. A multiple linear regression model was applied, with the intervention group and case mix adjusters as independent variables. We described differences in the number of symptoms discussed between patients receiving usual care and those receiving care post-implementation. Following implementation, 16 patients and 6 healthcare professionals were interviewed about their perceptions concerning the impact of and barriers to using the SOS-SAH. A thematic analysis was performed to identify the main themes. RESULTS: The survey did not reveal any differences between the usual-care group and the post-implementation group on the scales of the patient experience survey. After implementation of the SOS-SAH, the number of symptoms discussed during consultation did not increase. The interviews suggest that the SOS-SAH may improve the preparation of patients by providing them with greater insight into their complaints and by raising issues for the consultation. It could also enhance the structure and efficiency of consultation, in addition to improving communication about issues that matter to patients. All patients and healthcare professionals recommended continuing the use of the SOS-SAH in daily practice. CONCLUSIONS: Although no quantitative improvements were found in patient experience and symptoms discussed during consultation, implementation of the SOS-SAH could aid in screening for symptoms in patients after aSAH, and it might have a positive influence on patient preparation, while helping to structure consultations between patients and healthcare professionals.

WEB Treatment of Ruptured Intracranial Aneurysms: Long-Term Follow-up of a Single-Center Cohort of 100 Patients.

BACKGROUND AND PURPOSE: The Woven EndoBridge device (WEB) was introduced for the intrasaccular treatment of wide-neck aneurysms without the need for adjunctive devices. We used the WEB as a primary treatment for 100 ruptured aneurysms regardless of neck size or location. In this study, we present the long-term follow-up of 78 surviving patients. MATERIALS AND METHODS: Between February 2015 and April 2017, one hundred ruptured aneurysms were treated with the WEB. For surviving patients, angiographic and clinical follow-up was scheduled at 3 months, and 3T MRA and clinical follow-up, at 6, 12, 36, and 60 months. Of 100 patients, 18 died during hospital admission, and in 4, the ruptured aneurysm was additionally treated. The remaining 78 patients had a mean follow-up of 51 months (median, 52 months; range, 5-84 months). There were 57 women and 21 men, with a mean age of 58.5 years (median, 59 years; range, 24-80 years). Of 78 aneurysms with long-term follow-up, 52 (66%) had a wide neck. RESULTS: Of 78 ruptured aneurysms, 56 (72%) remained completely occluded and 17 (22%) had a stable small neck remnant. Five of 78 aneurysms (6%; 95% CI, 2.4%-14.5%) reopened during follow-up and were additionally treated. There were no rebleeds during follow-up. CONCLUSIONS: Treatment of ruptured aneurysms with the WEB was safe and effective and has long-term results comparable with those of simple coiling of small-neck aneurysms. The WEB proved to be a valuable alternative to coils for both wide- and small-neck ruptured aneurysms without the need for stents, balloons, or antiplatelet therapy.

Repeated Chlamydia trachomatis infections are associated with lower bacterial loads.

Chlamydia trachomatis (CT) infections remain highly prevalent. CT reinfection occurs frequently within months after treatment, likely contributing to sustaining the high CT infection prevalence. Sparse studies have suggested CT reinfection is associated with a lower organism load, but it is unclear whether CT load at the time of treatment influences CT reinfection risk. In this study, women presenting for treatment of a positive CT screening test were enrolled, treated and returned for 3- and 6-month follow-up visits. CT organism loads were quantified at each visit. We evaluated for an association of CT bacterial load at initial infection with reinfection risk and investigated factors influencing the CT load at baseline and follow-up in those with CT reinfection. We found no association of initial CT load with reinfection risk. We found a significant decrease in the median log10 CT load from baseline to follow-up in those with reinfection (5.6 CT/ml vs. 4.5 CT/ml; P = 0.015). Upon stratification of reinfected subjects based upon presence or absence of a history of CT infections prior to their infection at the baseline visit, we found a significant decline in the CT load from baseline to follow-up (5.7 CT/ml vs. 4.3 CT/ml; P = 0.021) exclusively in patients with a history of CT infections prior to our study. Our findings suggest repeated CT infections may lead to possible development of partial immunity against CT.

Treatment of cranial dural arteriovenous fistulas with exclusive cortical venous drainage: A single-center cohort of 35 patients.

Background and purpose Dural arteriovenous fistulas (DAVFs) with cortical venous drainage often present with hemorrhage or neurological deficits and prompt treatment is indicated. Disconnection of the draining vein is considered curative. We present the multimodality treatment results of 35 patients with cranial DAVFs with exclusive cortical venous drainage. Materials and methods Between January 2010 and January 2017, 35 consecutive patients with cranial dural fistulas with exclusive cortical venous drainage were treated. There were 27 men and eight women, mean age 68 years (range 45-87). Clinical presentation was hemorrhage in 23 (66%), pulsatile bruit in two (6%), seizures in one (3%) and blurred vision in one (3%). In eight patients (22%), the DAVF was an incidental finding. Location of the DAVFs was convexity in 25 (71%), posterior fossa in eight (23%) and tentorium in two (6%). Results Surgery was performed in four patients with anterior cranial fossa fistulas and in one patient with a tentorial dural fistula. In 30 patients, embolization with Onyx via the arterial route was the primary treatment with complete obliteration in one session in 25 patients. Additional surgical or endovascular sessions were necessary in five patients after incomplete embolization and in one patient after incomplete surgery. Obliteration was confirmed with angiography after three months. There were no procedural complications. Conclusions Patients with dural fistulas with cortical venous drainage were cured with a strategy of arterial endovascular treatment with Onyx and surgery. These techniques were either primarily successful or complementary. There were no complications of treatment.

WEB Treatment of Ruptured Intracranial Aneurysms: A Single-Center Cohort of 100 Patients.

BACKGROUND AND PURPOSE: The Woven EndoBridge device was recently introduced for the intrasaccular treatment of wide-neck aneurysms without the need for adjunctive devices. We present our results of the primary treatment of ruptured aneurysms with the Woven EndoBridge regardless of location or neck size. MATERIALS AND METHODS: Between February 2015 and April 2017, 100 ruptured aneurysms were selectively treated with the Woven EndoBridge. No supporting stents or balloons were used. There were 71 women treated (mean patient age, 59 years; median age, 60 years; range, 23-82 years). RESULTS: The mean aneurysm size was 5.6 mm (range, 3-13 mm), and 42 aneurysms were ≤4 mm. Sixty-six aneurysms (66%) had a wide neck, defined as ≥4 mm or a dome-neck ratio ≤1.5. There was 1 procedural rupture without sequelae. In 9 patients (9%), thromboembolic complications occurred. One poor grade patient died; neurologic deficits remained in 3. Overall treatment-related morbidity-mortality was 4% (4 of 100; 95% CI, 1.2%-10.2%).Two of 100 aneurysms were initially incompletely occluded and were additionally treated early after initial intervention. Of 80 eligible patients, 74 (93%) had 3-month angiographic follow-up. Fifty-four aneurysms (73%) were completely occluded, 17 (23%) had a small neck remnant, and 3 (4%) were incompletely occluded. One patient was additionally treated with a second Woven EndoBridge, and in 2 patients, additional treatment is scheduled. The overall reopening/retreatment rate was 6.8% (5 of 74; 95% CI, 2.6%-15.2%). There were no rebleeds during follow-up. CONCLUSIONS: Treatment of small ruptured aneurysms with the Woven EndoBridge was safe and effective. The Woven EndoBridge proved to be a valuable alternative to coils without the need for stents or balloons.

Tentorial Dural Arteriovenous Fistulas: A Single-Center Cohort of 12 Patients.

OBJECTIVE: Tentorial dural arteriovenous fistulas usually drain into cortical veins and often present with hemorrhage. Treatment goal is occlusion of the draining vein, either by surgery or endovascular techniques. We present the multimodality treatment results of 12 patients with tentorial dural arteriovenous fistulas. MATERIALS AND METHODS: Between January 2007 and January 2017, 12 consecutive patients with tentorial dural arteriovenous fistulas were treated. There were 11 men and 1 woman with a mean age of 62 years (range 44-85). Clinical presentation was hemorrhage in 8 (67%), pulsatile tinnitus in 2 (17%) and an incidental finding in 2 (17%). The fistula location was at the tentorium cerebelli in 5 (42%), the torcula Herophilii in 4 (33%) and petroclival in 3 (25%). RESULTS: In 11 patients, arterial embolization with Onyx or PHIL was the primary treatment. Complete obliteration was achieved in one session in 5 (45%) and in 2 sessions in 4 (36%). In 2 patients additional surgery was needed. Primary surgery was performed in 1 patient followed by endovascular coil occlusion via the venous route. One patient with exclusive pial feeders from the posterior inferior cerebellar artery had a clinically silent P3 occlusion during trans arterial embolization. Finally, all 12 fistula were completely occluded, confirmed with angiography after 8-12 weeks. There were no permanent procedural complications. CONCLUSION: Patients with tentorial dural arteriovenous fistulas were effectively and safely cured with a strategy of endovascular treatment with various techniques and surgery. Surgical and endovascular techniques are complementary in the treatment of these challenging vascular disorders.

Expanding sexually transmitted infection screening among women and men engaging in transactional sex: the feasibility of field-based self-collection.

Routine screening is a key component of sexually transmitted infection (STI) prevention and control; however, traditional programmes often fail to effectively reach men and women in hidden communities. To reduce prevalence, we must understand the programmatic features that would encourage utilization of services among asymptomatic individuals. Using incentivized snowball sampling, 44 women and men recently engaging in transactional sex were recruited (24 women, 20 men); median age 37 years. Respondents were offered the opportunity to collect genital, oropharyngeal and rectal samples for STI testing and completed a face-to-face interview about their experience with self-obtained sampling. Interviews were analysed using qualitative methods. Participants were unaware of potential risk for STI, but found self-sampling in non-clinical settings to be acceptable and preferable to clinic-based testing. All participants collected genital specimens; 96% and 4% collected oropharyngeal and rectal specimens, respectively. The burden of disease in this population was high: 38% tested positive for at least one STI. We detected multiple concomitant infections. Incorporating field collection of self-obtained samples into STI control programmes may increase utilization among high-risk populations unlikely to access clinic-based services. High infection rates indicate that individuals engaging in transactional sex would benefit from, and be responsive to, community-based self-sampling for STI screening.

Herpes simplex virus type 2 serological testing at a community court: predictors of test acceptance and seropositivity among female defendants.

Despite the high prevalence of herpes simplex virus type 2 (HSV-2), testing for asymptomatic infections is uncommon. One population for whom targeted interventions may be prioritized include individuals involved with the correctional system. Here we describe the acceptability of a novel HSV-2 screening program, implemented in a court setting, as a possible intervention for corrections-involved women. Female defendants completed an interviewer administered survey assessing factors associated with uptake/refusal of free point-of-care HSV-2 serologic testing and HSV-2 seropositivity. Participants included 143 women, 18-62 years old (mean 32.85) with diverse ethnicities. The majority (65.7%) accepted testing and 62.4% tested HSV-2 seropositive. Factors independently associated with test acceptance included higher perceived susceptibility to genital herpes infection and not receiving a preventative health screen. Women who were seropositive tended to be older, Black, report having previous STI, and be arrested on a prostitution charge. Findings suggest point-of-care testing in a court setting is acceptable to women and can be implemented to improve case finding of STI.

Chlamydia trachomatis clinical isolates identified as tetracycline resistant do not exhibit resistance in vitro: whole-genome sequencing reveals a mutation in porB but no evidence for tetracycline resistance genes.

Chlamydia trachomatis is the most common bacterial sexually transmitted infection worldwide and the leading cause of preventable blindness in developing countries. Tetracycline is commonly the drug of choice for treating C. trachomatis infections, but cases of antibiotic resistance in clinical isolates have previously been reported. Here, we used antibiotic resistance assays and whole-genome sequencing to interrogate the hypothesis that two clinical isolates (IU824 and IU888) have acquired mechanisms of antibiotic resistance. Immunofluorescence staining was used to identify C. trachomatis inclusions in cell cultures grown in the presence of tetracycline; however, only antibiotic-free control cultures yielded the strong fluorescence associated with the presence of chlamydial inclusions. Infectivity was lost upon passage of harvested cultures grown in the presence of tetracycline into antibiotic-free medium, so we conclude that these isolates were phenotypically sensitive to tetracycline. Comparisons of the genome and plasmid sequences for the two isolates with tetracycline-sensitive strains did not identify regions of low sequence identity that could accommodate horizontally acquired resistance genes, and the tetracycline binding region of the 16S rRNA gene was identical to that of the sensitive control strains. The porB gene of strain IU824, however, was found to contain a premature stop codon not previously identified, which is noteworthy but unlikely to be related to tetracycline resistance. In conclusion, we found no evidence of tetracycline resistance in the two strains investigated, and it seems most likely that the small, aberrant inclusions previously identified resulted from the high chlamydial load used in the original antibiotic resistance assays.

Discrepancies in diagnosis of incident HIV infection between antibody- and DNA-based tests in a phase III prevention trial in southern Africa.

Dried blood spots (DBS) are widely used to test for HIV in a variety of research and service delivery settings; however, uniform guidelines regarding collection, storage and DNA extraction processes have neither been developed nor evaluated. Previously published reports suggested DBS may be stored at room temperature for up to 60 days, and intensive stability tests have shown that DBS can withstand high temperatures, humidity and freeze-thawing. During the implementation of a large randomized controlled trial (RCT) in southern Africa, with HIV acquisition as the primary endpoint, we observed 65 instances when DBS samples collected from the same day as a positive HIV antibody test yielded negative DNA polymerase chain reaction (PCR) results. The source of this discrepancy may have been due to inadequate specimen volume, filter paper or DNA extraction procedures, but were most likely due to storage conditions that have been reported as acceptable in other settings.

Spinal dural fistulas without swelling and edema of the cord as incidental findings.

SUMMARY: SDAVFs cause hypertension and hence outflow obstruction in the perimedullary venous system resulting in swelling and edema of the cord followed by dysfunction. Clinical presentation is usually with gradual progressive paraparesis, numbness, and sphincter problems. MR imaging typically demonstrates the dilated perimedullary veins and the swelling and edema of the cord. During the past few years, we incidentally found an SDAVF on MR imaging with dilated perimedullary veins but without swelling and edema of the cord in 5 patients with unrelated presenting clinical symptoms. Spinal angiography confirmed the presence of an SDAVF in all 5 patients. Although the indication was considered questionable, eventually all 5 fistulas were endovascularly or surgically treated, resulting in normalization of the MR images.

Curative embolization of brain arteriovenous malformations with onyx: patient selection, embolization technique, and results.

BACKGROUND AND PURPOSE: A new curative embolization technique with Onyx for selected small and medium-sized superficially located brain AVMs was developed, which consists of obliteration of the nidus, including incremental occlusion of the draining veins. We report our first clinical results. MATERIALS AND METHODS: Between June 2008 and July 2011, 24 patients (7 women, 17 men; mean age, 41 years; range, 6-74 years) with AVMs were selected for curative embolization with Onyx. Presentation was hemorrhage in 14 and seizures in 10 patients. AVM location was frontal in 11, occipital in 6, parietal in 4, and temporal in 3. AVM size was a mean of 2.2 cm (median, 2; range, 1-3 cm). RESULTS: Complete angiographic obliteration of the AVM with Onyx in a single session was achieved in all 24 patients. There were no hemorrhagic or ischemic complications (0%; 95% CI, 0%-16.3%), and no new deficits induced by the treatment. Of 14 patients with ruptured AVMs, 1 patient who presented with a large frontal hematoma died shortly after surgical evacuation of the hematoma following complete embolization of a micro-AVM. Follow-up angiography at 3 months in 23 patients demonstrated a small AVM remnant in 1 that was treated with gamma knife radiosurgery. The other 22 AVMs remained completely occluded. CONCLUSIONS: In selected patients with small and medium-sized superficial brain AVMs, as defined in our study, injection of Onyx by using a curative embolization technique in a single session seems to provide a safe and effective alternative to radiosurgery or surgery.

Endovascular treatment of ruptured brain AVMs in the acute phase of hemorrhage.

BACKGROUND AND PURPOSE: Patients with ruptured brain AVMs are at considerable risk of repeat hemorrhage, particularly when associated intranidal or flow-related aneurysms are present. There is controversy about the timing of diagnosis and treatment of patients with hemorrhagic stroke. We present our results of endovascular treatment of ruptured AVMs in the acute phase. MATERIALS AND METHODS: Between January 2008 and March 2011, 23 patients (16 men, 7 women; mean age 42 years) with AVM-related hemorrhagic stroke were treated with endovascular techniques within 10 days of the ictus. There were 10 micro-AVMs (< 1 cm) and 1 single-hole pial fistula. In 9 patients, an intranidal or flow-related aneurysm was the likely cause of hemorrhage. RESULTS: Complete obliteration of the AVM with Onyx was achieved in 13 of 23 patients (57%). Eight of the 13 AVMs were micro-AVMs and 3 had an intranidal aneurysm. Partial obliteration of the AVM was achieved in 10 of 23 patients (43%). In 6 of these 10 patients, an intranidal (n = 1) or flow-related aneurysm (n = 5) was obliterated with Onyx or coils. There were no complications of treatment. During a mean follow-up of 21 months in 22 surviving patients, no repeat hemorrhage occurred. CONCLUSIONS: Endovascular treatment with Onyx in the acute phase cured most ruptured AVMs. All 9 AVM-associated aneurysms that were considered the source of hemorrhage could be excluded from the circulation. In patients with AVM-related hemorrhagic stroke, prompt angiographic diagnosis and treatment may improve prognosis by reducing repeat hemorrhage rate.

Low acceptance of HSV-2 testing among high-risk women.

We evaluated the acceptability of a community-based herpes simplex virus type 2 (HSV-2) screening programme for at-risk women and assessed factors related to uptake of point of care HSV-2 testing. One hundred recently arrested women (median age 34 years) were recruited from a community court handling lower-level misdemeanour cases in Indianapolis, Indiana. Individuals completed a survey assessing factors related to HSV-2 screening intentions and were offered point of care HSV-2 testing. Rates of HSV-2 infection in this population are high; 61.1% of women tested were positive. The majority (81%) accepted a prescription for suppressive therapy. Women in this sample indicated that HSV-2 screening is an important component of health care but were unwilling to pay the US$10 it cost to be tested. To encourage this and other high-risk populations to be screened for HSV-2, public health resources will be needed to help individuals overcome cost-related barriers to care.

Variations in CD4 cell counts among HIV-uninfected and infected women in Uganda and Zimbabwe.

We conducted a cross-sectional study with 208 HIV-uninfected and 188 HIV-infected women in Uganda and Zimbabwe to investigate differences in median CD4 counts. Absolute CD4 counts were determined by flow cytometry. Multivariate analyses were used to examine the association of country and HIV-infection status on CD4 counts. Median CD4 counts were significantly lower in Zimbabwe than in Uganda overall (649 and 783 cells/mm(3), P = 0.009) and among HIV-infected women (470 and 614 cells/mm(3), P = 0.003). In separate multivariable models, CD4 counts were significantly lower in Zimbabwe in HIV-uninfected (P = 0.014) and infected (P < 0.001) women, controlling for age, contraceptive method, education and living with partner status. In a model combining HIV-uninfected and infected women, there was no significant interaction between country and HIV infection status (P = 0.344), suggesting that the relationship between country and CD4 count was not significantly modified by HIV infection status. This study reinforces the importance of establishing country-specific reference CD4 levels as CD4 count continues to be used as a key biomarker in clinical decision-making for HIV-infected individuals in sub-Saharan Africa.

Field collection of rectal samples for sexually transmitted infection diagnostics among men who have sex with men.

Rectal sexually transmitted infections (STIs) are common in men at risk for urethral infections with these pathogens, particularly men who have sex with men (MSM). However, for those individuals not regularly seen by a clinician, screening for rectal STI is not currently a widespread option. Qualitative data and samples (i.e. self-obtained rectal specimens) were collected from 75 MSM in a variety of venues. Upon completion of the rectal self-sampling, each participant completed a brief interview regarding their overall experience with the process. Participants reported an overall high level of acceptability and comfort-level involved with self-sampling for rectal STI. Of the majority of men who agreed to provide a rectal self-sample, all reported that they would provide a sample again in the future. However, many men also appreciated the interaction with a health-care provider that a clinical setting offered. In conclusion, self-sampling is a feasible and acceptable option when offered to MSM in a range of community-based venues. Further research is needed to determine which combinations of STI testing and treatment methods (including self-sampling) are most appropriate for diverse groups of men.

Vaginal yeast colonisation, prevalence of vaginitis, and associated local immunity in adolescents.

OBJECTIVES: To evaluate point prevalence vaginal yeast colonisation and symptomatic vaginitis in middle adolescents and to identify relation of these yeast conditions with reproductive hormones, sexual activity, sexual behaviours, and associated local immunity. METHODS: Middle adolescent females (n = 153) were evaluated for sexually transmitted infections (STIs), asymptomatic yeast colonisation, and symptomatic vulvovaginal candidiasis (VVC) by standard criteria. Also evaluated were local parameters, including vaginal associated cytokines, chemokines, and antibodies, vaginal epithelial cell antifungal activity, and Candida specific peripheral blood lymphocyte responses. Correlations between yeast colonisation/vaginitis and local immunomodulators, reproductive hormones, douching, sexual activity, condom use, and STIs were identified. RESULTS: Rates of point prevalence asymptomatic yeast colonisation (22%) were similar to adults and similarly dominated by Candida albicans, but with uncharacteristically high vaginal yeast burden. In contrast with the high rate of STIs (18%), incidence of symptomatic VVC was low (<2%). Immunological properties included high rates of Candida specific systemic immune sensitisation, a Th2 type vaginal cytokine profile, total and Candida specific vaginal antibodies dominated by IgA, and moderate vaginal epithelial cell anti-Candida activity. Endogenous reproductive hormones were in low concentration. Sexual activity positively correlated with vaginal yeast colonisation, whereas vaginal cytokines (Th1, Th2, proinflammatory), chemokines, antibodies, contraception, douching, or condom use did not. CONCLUSION: Asymptomatic vaginal yeast colonisation in adolescents is distinct in some ways with adults, and positively correlates with sexual activity, but not with local immunomodulators or sexual behaviours. Despite several factors predictive for VVC, symptomatic VVC was low compared to STIs.

Evaluation of the Digene Hybrid Capture II Assay with the Rapid Capture System for detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

Screening for chlamydial and gonococcal infection has been strongly recommended for all sexually active women under the age of 26. Advances in the ability to detect infection by nucleic acid detection techniques have improved access to screening methods in routine clinical practices. To meet the increasing demand for testing, a high-throughput system is desirable. We evaluated the performance of the Hybrid Capture 2 CT/GC (HC2) assay with the Digene Rapid Capture System (HC2-RCS). The results of HC2-RCS for endocervical samples from 330 women were compared to those of culture and the COBAS Amplicor PCR. For detection of chlamydial infection, HC2-RCS had a sensitivity and a specificity similar to those of PCR (P > 0.5) and an improved sensitivity compared to that of culture (P = 0.007). For identification of gonococcal infections, all assays performed similarly (P > 0.5). The performance of HC2-RCS was also compared to that of the manual HC2 format (HC2-M) with these samples and with 911 endocervical samples collected previously. The performance of HC2-RCS was equivalent to that of HC2-M; the overall concordance rates for the detection of chlamydia and gonorrhea were 99.7% (kappa = 0.97) and 99.8% (kappa = 0.97), respectively. When the HC2 assay was performed with a semiautomated system application designed for high throughput, it demonstrated high sensitivity and a high specificity for detection of both Chlamydia trachomatis and Neisseria gonorrhoeae.

Enhancing the specificity of the COBAS AMPLICOR CT/NG test for Neisseria gonorrhoeae by retesting specimens with equivocal results.

The COBAS AMPLICOR CT/NG test for Neisseria gonorrhoeae cross-reacts with certain strains of nonpathogenic Neisseria species. In some strains, the target sequence is identical to that of N. gonorrhoeae, whereas other strains have a small number of mismatches within the regions recognized by the primers or probe used in the COBAS AMPLICOR NG test. These cross-reactive strains are occasionally present in urogenital specimens, causing false-positive results in the COBAS AMPLICOR NG test. Analysis of the data generated in a large multicenter clinical trial showed that 2.9% of the specimens gave signals between A(660)s of 0.2 and 3.5 but that one-half of these equivocal specimens did not contain N. gonorrhoeae. Most of these equivocal specimens were correctly classified as true positive or true negative by retesting in duplicate and defining a PCR-positive result as two of three results with an A(660) of > or =2.0. If specimens had been classified as positive or negative based on a single test result using a cutoff of an A(660) of 0.2, specificity would have ranged from 96.2 to 98.9% depending on specimen type, sex, and presence of symptoms. By employing the equivocal zone-retesting algorithm, specificity increased to 98.6 to 99.9% with little effect (0.1 to 4.9% decrease) on sensitivity in most specimen types, enabling the test to achieve a positive predictive value of at least 90% in populations with a prevalence of 4% or higher. In lower-prevalence populations, the test could be used to screen for presumptive infections that would have to be confirmed by an independent test.