Comparison of a Ligase Chain Reaction-Based Assay and Cell Culture for Detection of Pharyngeal Carriage ofChlamydia trachomatis

2000 ◽  
Vol 38 (9) ◽  
pp. 3502-3504 ◽  
Author(s):  
Andrew J. Winter ◽  
Gerry Gilleran ◽  
Kirstine Eastick ◽  
Jonathan D. C. Ross

In 264 genitourinary medicine clinic attenders reporting recent fellatio, the prevalence of pharyngeal Chlamydia trachomatis determined by an expanded standard including cell culture and two in-house PCR tests was 1.5% in 194 women and zero in 70 men. The ligase chain reaction (Abbott LCx) had a specificity of 99.2% and a positive predictive value of 60%.

1996 ◽  
Vol 49 (2) ◽  
pp. 116-119 ◽  
Author(s):  
G L Ridgway ◽  
G Mumtaz ◽  
A J Robinson ◽  
M Franchini ◽  
C Carder ◽  
...  

1999 ◽  
Vol 37 (9) ◽  
pp. 3072-3073 ◽  
Author(s):  
K. B. Waites ◽  
K. R. Smith ◽  
M. A. Crum ◽  
R. D. Hockett ◽  
A. H. Wells ◽  
...  

Ligase chain reaction (LCR) was compared with ACCESS immunoassay for detection of chlamydial infections in females. Despite efforts to improve ACCESS performance by evaluation of specimens that were in the test performance “grey zone,” LCR remained more sensitive and was less expensive to perform. ACCESS had a sensitivity of 83.9%, a specificity of 99.7%, a positive predictive value of 96.3%, and a negative predictive value of 98.5%.


1998 ◽  
Vol 6 (2) ◽  
pp. 57-60 ◽  
Author(s):  
J. D. Davis ◽  
P. K. Riley ◽  
C. W. Peters ◽  
K. H. Rand

Objective:To compare the reliability of ligase chain reaction (LCR) to polymerase chain reaction (PCR) in detectingChlamydia trachomatisendocervical infections.Methods:We conducted a prospective study of 486 patients at risk for chlamydial infection of the endocervix. We obtained two endocervical specimens from each patient and used LCR and PCR to detectC. trachomatis. Discrepant results between the two techniques were resolved by repeat testing and by testing for the major outer membrane protein (MOMP) gene, if necessary. We determined the sensitivity, specificity, positive predictive value, and negative predictive value for each test, using concordant results or MOMP gene results as the “gold standard”.Results:Of the 486 patients, 42 (8.6%) had evidence ofC. trachomatisinfection after resolution of discrepant results. Of the 42 true positive specimens, 41 were positive by initial LCR and 38 were positive by initial PCR. Of the 444 true negative specimens, none had a positive initial LCR result, while 2 had a positive initial PCR test. Therefore, compared to the gold standard, LCR had a sensitivity of 97.6% and specificity of 100%, while PCR had a sensitivity of 90% and a specificity of 99.5%. The positive and negative predictive values of LCR were 100% and 99.8%, respectively. PCR had a positive predictive value of 95% and a negative predictive value of 99.1%. The difference in sensitivity of LCR versus PCR was not statistically significant (P= .125).Conclusion:LCR and PCR perform equally well in detectingC. trachomatisendocervical infections.


2000 ◽  
Vol 38 (7) ◽  
pp. 2480-2483 ◽  
Author(s):  
J. Kapala ◽  
D. Copes ◽  
A. Sproston ◽  
J. Patel ◽  
D. Jang ◽  
...  

Specimen pooling to achieve efficiency when testing urine specimens for Chlamydia trachomatis nucleic acids has been suggested. We pooled endocervical swabs from 1,288 women and also tested individual swabs by ligase chain reaction (LCR). Out of 53 positive specimens, pools of 4 or 8 specimens missed two positives, providing 96.2% accuracy compared to individual test results. Dilution and positive-control spiking experiments showed that negative specimens with inhibitors of LCR in the pool reduced the signal. Conversely, two extra positives, detected only through pooling, were negative by individual testing but became positive after storage, suggesting that fresh positive specimens with labile inhibitors may be positive in a pool because of dilution of inhibitors. For this population of women with a 4% prevalence of C. trachomatis infection, substantial savings in cost of reagents (55 to 63%) and technologist time (50 to 63%) made pooling strategies a desirable alternative to individual testing.


2013 ◽  
Vol 24 (3) ◽  
pp. e69-e74 ◽  
Author(s):  
PD Andrade ◽  
MT Fioravanti ◽  
EBV Anjos ◽  
C De Oliveira ◽  
DM Albuquerque ◽  
...  

BACKGROUND: Human cytomegalovirus is an important cause of morbidity and mortality in immunocompromised patients. Qualitative polymerase chain reaction (PCR) has proven to be a sensitive and effective technique in defining active cytomegalovirus infection, in addition to having low cost and being a useful test for situations in which there is no need for quantification. Real-time PCR has the advantage of quantification; however, the high cost of this methodology makes it impractical for routine use.OBJECTIVE: To apply a nested PCR assay to serum (sPCR) and to evaluate its efficiency to diagnose active cytomegalovirus infection compared with PCR of peripheral blood leukocytes (L-PCR).METHODS: Samples of 37 patients were prospectively evaluated. An internal control was created and applied to sPCR to exclude false-negative results.RESULTS: In total, 21 patients (57%) developed active cytomegalovirus infection. After analyzing the two methods for the diagnosis of active infection, higher sensitivity and negative predictive value of the L-PCR versus sPCR (100% versus 62%), and higher specificity and positive predictive value of sPCR versus L-PCR (81% versus 50% and 72%, respectively) were observed. Discordant results were observed in 11 patients who were L-PCR-positive but sPCR-negative for active cytomegalovirus infection, five of whom developed clinical symptoms of cytomegalovirus. Clinical symptoms were observed in 14 patients, 12 of whom were diagnosed with active infection by nested L-PCR (P=0.007) and seven by nested sPCR (P=0.02). Higher specificity and a positive predictive value for sPCR were observed.CONCLUSION: Nested L-PCR and sPCR were considered to be complementary methods for the diagnosis and management of symptomatic cytomegalovirus infection.


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