IMPORTANCE Early and accurate in vivo diagnosis of Creutzfeldt-Jakob disease (CJD) is necessary for quickly distinguishing treatable from untreatable rapidly progressive dementias and for future therapeutic trials. This early diagnosis is becoming possible using the real-time quaking-induced conversion (RT-QuIC) seeding assay, which detects minute amounts of the disease-specific pathologic prion protein in cerebrospinal fluid (CSF) or olfactory mucosa (OM) samples.OBJECTIVE To develop an algorithm for accurate and early diagnosis of CJD by using the RT-QuIC assay on CSF samples, OM samples, or both. DESIGN, SETTING, AND PARTICIPANTSIn this case-control study, samples of CSF and OM were collected from 86 patients with a clinical diagnosis of probable (n = 51), possible (n = 24), or suspected (n = 11) CJD and 104 negative control samples (54 CSF and 50 OM). The CSF and OM samples were analyzed using conventional RT-QuIC. The CSF samples underwent further testing using improved RT-QuIC conditions. In addition, the diagnostic performance of a novel, easy-to-use, gentle flocked swab for sampling of OM was evaluated. Data were collected from January 1 to June 30, 2015. MAIN OUTCOME AND MEASURES Correlations between RT-QuIC results and the final diagnosis of recruited patients.RESULTS Among the 86 patients (37 men [43%] and 49 women [57%]; mean [SD] age, 65.7 [11.5] years) included for analysis, all 61 patients with sporadic CJD had positive RT-QuIC findings using OM or CSF samples or both for an overall RT-QuIC diagnostic sensitivity of 100% (95% CI, 93%-100%). All patients with a final diagnosis of non-prion disease (71 CSF and 67 OM samples) had negative RT-QuIC findings for 100% specificity (95% CI, 94%-100%). Of 8 symptomatic patients with various mutations causing CJD or Gerstmann-Sträussler-Scheinker syndrome, 6 had positive and 2 had negative RT-QuIC findings for a sensitivity of 75% (95% CI, 36%-96%). CONCLUSIONS AND RELEVANCEA proposed diagnostic algorithm for sporadic CJD combines CSF and OM RT-QuIC testing to provide virtually 100% diagnostic sensitivity and specificity in the clinical phase of the disease.

Significantly more epithelial cells were collected by flocked swabs than by rayon swabs in parallel nasopharyngeal and nasal swabs taken from 16 volunteers. Nasopharyngeal sampling of 61 symptomatic patients also yielded more cells by flocked than rayon swabs, providing better clinical specimens for diagnosis.

We developed and evaluated flocked nasal midturbinate swabs obtained from 55 asymptomatic and 108 symptomatic volunteers. Self-collected swabs obtained from asymptomatic volunteers yielded numbers of respiratory epithelial cells comparable to those of staff-collected nasal (n ‫؍‬ 55) or nasopharyngeal (n ‫؍‬ 20) swabs. Specific viruses were detected in swabs self-collected by 42/108 (38.9%) symptomatic volunteers by multiplex PCR.We report herein the design and evaluation of a novel selfcollected nasal midturbinate swab for respiratory virus diagnosis. We previously demonstrated that Copan flocked nasopharyngeal swabs (NPS) collected significantly more respiratory epithelial cells than conventional rayon swabs and improved sample collection for direct fluorescent antibody (DFA) testing of respiratory viruses (2). We observed that the cell yield obtained from sampling the nose using a flocked swab designed for nasopharyngeal sampling was equivalent to that obtained from nasopharyngeal sampling using rayon NPS. This led us to hypothesize that a flocked nasal swab designed to contact a larger nasal surface area would further improve cell sampling and enable self-collection.We measured the nasal passages of adult white cadavers at the Michael G. DeGroote School of Medicine anatomy laboratory, McMaster University, and designed a tapered coneshaped swab with a greater length and diameter of flocked nylon ( Fig. 1). A collar was added at 5.5 cm as a guide to maximum insertion depth for adults. The nasal swab samples a large surface area of respiratory mucosa, covering the inferior and middle turbinate bones, and is now commercially available in pediatric and adult sizes (FLOQSwabs; Copan Italia S.p.A., Brescia, Italy).Our primary study objectives were to determine the feasibility, acceptability, and performance characteristics of selfsampled nasal midturbinate swabs. We tested the adequacy of self-collected flocked nasal swabs, the equivalence of nasal and nasopharyngeal sampling, and the diagnostic yield for specific respiratory viruses by multiplex PCR. The study protocol was approved by the Research Ethics Board at St. Joseph's Healthcare, Hamilton, Ontario, Canada.To examine the adequacy of respiratory specimen self-collection, 55 healthy asymptomatic adult volunteers were recruited from hospital staff and visitors. After providing signed informed consent, volunteers self-collected two flocked nasal swabs by following the printed instructions with illustrations. Each swab was inserted up to 5.5 cm, as tolerated, into the same nostril of their choice. An experienced staff member then collected the following two additional nasal swabs, using the opposite nostril in randomized order: a flocked midturbinate nasal swab and a rayon pernasal swab. A self-administered questionnaire assessed the ease of self-collection, discomfort, and swab preferences.All four nasal swabs were placed into universal transport medium (UTM; Copan Italia S.p.A.) and coded to maintain blinding. Samples were processed identically, according to c...

By using commercially available spectrophotometric and immunofluorescent immunoassays, Chlamydia trachomatis antigens were detected in first-void urine (FVU) sediments from 224 men attending a sexually transmitted disease clinic at a frequency of 81.6%-86.8% compared with 86.8% (33/38) positive by urethral swab culture (P less than .05). Endocervical cultures from 228 women attending a gynecology clinic yielded 92.3% (12/13) positive compared with 61.5%-76.9% for urine samples in three antigen-detection assays. Culturing urine from either gender yielded low positivity rates (23.7% for men, 15.4% for women). Defining truly infected patients as positive by culture or by any two of the three antigen tests, all assays were 100% specific. Immunodiagnostic testing of male FVU sediment appears to be a reliable, rapid, nontraumatic method for diagnosing chlamydia infection.

Chlamydia trachomatis antigens were detected in populations with the following infection prevalences: 26.5% (36 of 136) of men and 27.7% (48 of 173) of women attending a sexually transmitted disease clinic, 16.3% (53 of 324) of women attending a Planned Parenthood clinic, and 3.4% (4 of 117) of an obstetrics and gynecologic practice. Compared with cell culture of the combined female cervical specimens (15.8% prevalence), the respective sensitivities of Chlamydiazyme (Abbott Laboratories, North Chicago, Illinois) and Microtrak (Syva, Palo Alto, California) were 98.3% and 87.9%, specificities were 97.5% and 98.4%, positive predictive values were 87.7% and 92.7%, and negative predictive values were 99.7% and 97.5%. Both assays were 70.0% sensitive with male urethral specimens, and the other parameters of performance ranged between 84.0% and 97.2%. The antigen detection assays, compared with culture, performed equally well in subjects without or with clinical signs.