Clinical evaluation of an automated enzyme-linked fluorescent assay for the detection of chlamydial antigen in specimens from high-risk patients.

A fully automated enzyme-linked fluorescent assay (ELFA) on the Vitek Immunodiagnostic Assay System (VIDAS CHL) was evaluated for the detection of chlamydial antigen in specimens from symptomatic and asymptomatic high-risk patients. The results were compared with those from McCoy cell culture and Chlamydiazyme with a blocking assay. False-positive VIDAS specimens were centrifuged and the pellet stained with direct fluorescent antibody (DFA). Of the 158 urine specimens, 52 (33%) were infected by Chlamydia trachomatis. The sensitivity and specificity of the VIDAS when compared with cell culture, DFA, and Chlamydiazyme were 75% and 96%, respectively, for urine specimens while the predictive value of a positive (PVP) and a negative (PVN) were 91% and 88%, respectively. Of the 245 urethral swabs, 75 (31%) were considered positive. The sensitivity and specificity were 71% and 92%, respectively, and the PVP and PVN were 80% and 87%, respectively. The sensitivity and specificity on the 108 cervical swabs, 22 of which were positive, were 95% and 95%, respectively, and PVP and PVN were 88% and 99%, respectively. Compared with Chlamydiazyme, the VIDAS was more sensitive on specimens from female patients and urine specimens, but less sensitive on urethral specimens from male patients.

Psoriasis treatment: bathing in a thermal lagoon combined with UVB, versus UVB treatment only.

We have compared bathing in a thermal lagoon in Iceland, combined with UVB treatment, to UVB treatment only in an open comparative study. Twenty-three psoriasis patients bathed 3 times daily and were treated with UVB 5 times a week for 4 weeks. The control group was only treated with UVB 5 times a week for 4 weeks. Psoriasis Area and Severity Index (PSAI) was used to estimate the severity of the disease. The mean PASI score in the bathing group decreased from 20.8 to 2.8 (p < 0.01). In the control UVB group, the PASI score decreased from 16. 7 to 6.9. The percentage difference between the groups was significant after 1, 2, 2 and 4 weeks. Bathing in the lagoon combined with UVB was found to be a very effective treatment and better than UVB treatment in our control group.

Comparison of Roche Cobas Amplicor and Abbott LCx for the rapid detection of Chlamydia trachomatis in specimens from high-risk patients.

OBJECTIVE: To evaluate two automated amplification systems for the detection of Chlamydia trachomatis in urogenital specimens, the Cobas Amplicor (Roche Diagnostic Systems, Branchburg, NJ) and the LCx (Abbott Laboratories, Abbott Park, IL). STUDY DESIGN: The two systems were compared testing specimens from 302 high-risk patients, including 98 female cervical swab specimens and 204 male urine specimens. The patients attended the state STD clinic in Reykjavik, Iceland, either because of symptoms or as a result of contract tracing. RESULTS: The prevalence of C. trachomatis infection was 15.3% in women and 13.2% in men. For the male urine specimens, the sensitivity and specificity were 100% and 99.4% for the Cobas Amplicor and 74.1% and 100% for the LCx. In the cervical swabs, both systems detected all 15 true-positive specimens. The internal control used with the Cobas Amplicor detected inhibition in 2% of the male urine and 20% female cervical swabs, respectively. CONCLUSION: The Cobas Amplicor demonstrated slightly better sensitivity than LCx in male urine specimens. Both systems offer the benefits of automation for routine diagnostic testing.

[Diagnosis of chlamydia trachomatis infections in women: urinary PCR compared to cervical culture and PCR on cervical swabs in high risk females.].

Diagnosis of Chlamydia trachomatis infections in women has traditionally depended on cell culture or enzyme linked immunoassay. Recently Polymerase Chain Reaction (PCR) has been shown to be more sensitive than these methods when performed on endocervical swabs. A total of 203 high risk females were enrolled in a comparative study of three methods for diagnosing C. trachomatis infections: McCoy cell culture and Amplicor(R) PCR on endocervical swabs and urine. Thirty four had positive cultures, 38 positive PCR from cervix and 37 had positive PCR on urine specimens. When discrepancy occurred, the leftover Amplicor(R) specimen was retested by Roche with Amplicor(R) and a primer for the Major Outer Membrane Protein (MOMP) gene. None was false positive in cell culture or in urinary PCR but two were false positive in cervical PCR. In all three tests, 32 were positive. The sensitivity of culture was 87%, 92% in cervical PCR and 95% in urinary PCR. The specificity was 100% in both culture and urinary PCR but 98% in cervical PCR. The results show that Amplicor(R) PCR performed on female urine is more sensitive and as specific as cell culture.

[Clinical evaluation of a rapid polymerase chain reaction (PCR) assay: for the detection of chlamydia trachomatis in specimens from high risk patients.].

A Rapid Polymerase Chain Reaction Assay (Ampli-cor(R)-PCR) was evaluated for the detection of Chlamydia trachomatis in specimens from 179 high risk patients. The results were compared to McCoy cell culture and specimens were retested with Amplicor(R) and primers for the Major Outer Membrane Protein (MOMP) gene when discrepancy occurred. Of 88 females enrolled in the study, 30 were infected (34%). Sensitivity, selectivity, predictive value of a positive (PVP) and a negative (PVN) on endocervical specimens were 97%, 96.5%, 96.5% and 98% respectively. Of 91 male urine specimens, 33 (36%) came from infected patients. The sensitivity and specificity of the Amplicor(R) assay was 94% and 74% respectively for male urine specimens and the PVP and PVN were 72% and 96% respectively. The sensitivity was low on the original run on urethral specimens but the majority of false negative specimens became positive when retested. Amplicor(R) performed on urine samples was the most sensitive test for detecting Chlamydial infections in males.

Diagnosis of Chlamydia trachomatis infection in high-risk females with PCR on first void urine.

Recently the polymerase chain reaction (PCR) has been shown to be more sensitive than older methods in detecting Chlamydia trachomatis, when performed on endocervical swabs. A total of 203 high-risk females were enrolled in a comparative study of 3 methods for diagnosing C. trachomatis infections: McCoy cell culture and Amplicor PCR on endocervical swabs, and urine. Thirty-four had positive cultures, 38 positive PCR from cervix and 37 had positive PCR on urine specimens. When discrepancy occurred, the leftover Amplicor specimen was retested by Roche with Amplicor and a primer for the major outer membrane protein (MOMP) gene. In all three tests, 32 were positive. The sensitivity of culture was 87%, 92% in cervical PCR and 95% in urinary PCR. The specificity was 100% in both culture and urinary PCR but 98% in cervical PCR. Amplicor PCR performed on female urine is at least as sensitive and specific as cell culture.

[Clinical evaluation of two immunoassay methods for the rapid detection of chlamydia trachomatis: antigen in endocervical specimens from high risk female patients.].

Two rapid immunoassay methods, QuickVue-Chlamydia (Quidel Corp., San Diego California) and Kodak Surecell (Kodak Corp. Rochester, N.Y.) were evaluated for the detection of Chlamydia trachomatis antigen in endocervical swabs from high risk females attending a sexually transmitted disease clinic. The results were compared to McCoy cell culture and a polymerase chain reaction assay (Amplicor(R)-PCR, Roche Molecular Systems). Of the 240 females enrolled in the study 45 were considered infected (18.8%). Sensitivity, specificity, predictive value of a positive (PVP) and predictive value of a negative (PVN) of the QuickVue-Chlamydia assay were 96%, 99%, 96% and 99% respectively. Sensitivity, specificity, PVP and PVN of the Surecell assay were 96%, 100%, 100% and 99% respectively. The performance of the two immunoassay methods was similar, the sensitivity was the same and the specificity of the Kodak Surecell was slightly better than that of the QuickVue. On the other hand, the QuickWVL-Chlamydia assay was considerably simpler to perform (fewer steps) than the Kodak Surecell assay and took significantly less of technologists time.