scholarly journals Pooling of Urine Samples for Screening for Neisseria gonorrhoeae by Ligase Chain Reaction: Accuracy and Application

1998 ◽  
Vol 36 (12) ◽  
pp. 3624-3628 ◽  
Author(s):  
Katherine A. Kacena ◽  
Sean B. Quinn ◽  
Suzanne C. Hartman ◽  
Thomas C. Quinn ◽  
Charlotte A. Gaydos
Keyword(s):  
High School Students ◽  
Neisseria Gonorrhoeae ◽  
Nurse Practitioners ◽  
Urine Samples ◽  
Chain Reaction ◽  
School Students ◽  
Ligase Chain Reaction ◽  
Military Recruits ◽  
Specific Culture ◽  
Urine Specimens

The accuracy of detection of genital Neisseria gonorrhoeae infection in pooled urine samples by ligase chain reaction (LCR) was examined in three populations. Firstly, urine specimens from 300 female military recruits (FMR) were tested by LCR individually and in pools of four and six. Secondly, 300 urine specimens from middle-school students (MSS) were tested individually by LCR, and then the processed specimens were stored frozen for subsequent testing in pools of 4 and 10. Thirdly, 600 frozen urine specimens from high-school students (HSS) were tested by using the LCR pooling algorithm, i.e., testing processed specimens in pools of four in one test unit dose, and retesting individual specimens from positive pools. Finally, the pooling algorithm results were compared to culture results for a subset of 344 students from the original 600 HSS from whom cervical or urethral samples were taken at the discretion of the school nurse practitioners. Compared to individual testing of specimens by LCR in the FMR population, the pooling-by-four algorithm was 100% sensitive (5 of 5) and 100% pool specific (70 of 70), and the pool-by-six algorithm was 100% sensitive (5 of 5) and 100% pool specific (45 of 45). In the MSS population, the pool-by-4 algorithm was 95.8% sensitive (23 of 24) and 100% (52 of 52) pool specific, and the pool-by-10 algorithm was 95.8% sensitive (23 of 24) and 100% (17 of 17) pool specific. In the subset of 344 HSS from whom endocervical or urethral specimens were collected for culture, 31 were positive by LCR in urine and 26 were positive by culture. After results discrepant between culture and LCR were adjudicated by a confirmatory LCR test, the pooling algorithm was 93.8% (30 of 32) sensitive and 99.7% (311 of 312) specific. Culture from these 344 HSS was 81.3% (26 of 32) sensitive. The pooling algorithm reduced the cost of the N. gonorrhoeae LCR assay by 60% compared to individual testing of the HSS specimens and was both sensitive and specific.

scholarly journals Evaluation of the Abbott LCx Ligase Chain Reaction Assay for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in Urine and Genital Swab Specimens from a Sexually Transmitted Disease Clinic Population

1998 ◽  
Vol 36 (6) ◽  
pp. 1630-1633 ◽  
Author(s):  
Karen C. Carroll ◽  
William E. Aldeen ◽  
Michael Morrison ◽  
Roberta Anderson ◽  
Deborah Lee ◽  
...  
Keyword(s):  
Data Analysis ◽  
Chlamydia Trachomatis ◽  
Neisseria Gonorrhoeae ◽  
Positive Result ◽  
Transmitted Disease ◽  
Urine Samples ◽  
Chain Reaction ◽  
Ligase Chain Reaction ◽  
Pilin Gene ◽  
Urine Specimens

The Abbott LCx ligase chain reaction (LCR) assay for the simultaneous detection of Chlamydia trachomatis andNeisseria gonorrhoeae was evaluated by using swab and urine specimens from 562 patients. C. trachomatis results by LCR were compared to those by the Gen-Probe PACE 2 assay, whereas N. gonorrhoeae results by LCR were compared to those by culture. The Gen-Probe and LCR assays were performed according to the manufacturers’ instructions. Gram-negative diplococci growing on modified Thayer-Martin medium were confirmed as N. gonorrhoeae by the GonoGen II assay. Supplemental data analysis was performed by major outer membrane protein PCR for C. trachomatis and probes for pilin gene detection for N. gonorrhoeae. A true-positive result for each pathogen was defined as a positive result for all three or two of three assays. Overall agreement among the six assays was 94.8%. C. trachomatis prevalence was 16.2%; N. gonorrhoeae prevalence was 5.5%. The overall sensitivity and specificity, respectively, for each test (after supplemental data analysis) were as follows: for C. trachomatis, Gen-Probe, 65.9 and 100%; LCR on urine, 90.1 and 100%; LCR on swab specimens, 96.7 and 100%; and for N. gonorrhoeae, culture, 80.6 and 100%; LCR on urine, 93.5 and 99.8%; and LCR on swab specimens, 96.8 and 100%. For women, theN. gonorrhoeae culture was very insensitive compared to its performance in men (58.3 versus 94.7%, respectively). ForC. trachomatis, the Gen-Probe assay’s sensitivity was lower for men than for women (62.3 versus 71.1%, respectively). The sensitivity for C. trachomatis detection by LCR on urethral and cervical swab specimens was 96.2 and 97.4% for men and women, respectively. For men, swab results were slightly better than urine results for both pathogens (sensitivity for C. trachomatis in swab and urine specimens, 96.2 and 92.5%, respectively; sensitivity for N. gonorrhoeae in swab and urine specimens, 100 and 94.7%, respectively), while for women, cervical swabs were superior in sensitivity to urine samples for detecting C. trachomatis (swab, 97.4%; urine, 81.6%) and equivalent for N. gonorrhoeae (swab, 92.3%; urine, 91.6%). The LCx LCR appears to be both sensitive and specific for the detection of C. trachomatis andN. gonorrhoeae when performed on urine or genital swab samples. Swab samples had better sensitivity than urine samples for the detection of both pathogens.

scholarly journals Pooling Urine Samples for Ligase Chain Reaction Screening for Genital Chlamydia trachomatis Infection in Asymptomatic Women

1998 ◽  
Vol 36 (2) ◽  
pp. 481-485 ◽  
Author(s):  
Katherine A. Kacena ◽  
Sean B. Quinn ◽  
M. René Howell ◽  
Guillermo E. Madico ◽  
Thomas C. Quinn ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Cost Savings ◽  
Urine Samples ◽  
Chain Reaction ◽  
Ligase Chain Reaction ◽  
Chlamydia Trachomatis Infection ◽  
Population Prevalence ◽  
Pooled Samples ◽  
Asymptomatic Women ◽  
Urine Specimens

The accuracy of pooling urine samples for the detection of genitalChlamydia trachomatis infection by ligase chain reaction (LCR) was examined. A model was also developed to determine the number of samples to be pooled for optimal cost savings at various population prevalences. Estimated costs included technician time, laboratory consumables, and assay costs of testing pooled samples and retesting individual specimens from presumptive positive pools. Estimation of population prevalence based on the pooled LCR results was also applied. After individual urine specimens were processed, 568 specimens were pooled by 4 into 142 pools and another 520 specimens were pooled by 10 into 52 pools. For comparison, all 1,088 urine specimens were tested individually. The sample-to-cut-off ratio was lowered from 1.0 to 0.2 for pooled samples, after a pilot study which tested 148 samples pooled by 4 was conducted. The pooling algorithm was 100% (48 of 48) sensitive when samples were pooled by 4 and 98.4% (61 of 62) sensitive when samples were pooled by 10. Although 2.0% (2 of 99) of the negative pools of 4 and 7.1% (1 of 14) of the negative pools of 10 tested presumptive positive, all samples in these presumptive-positive pools were negative when retested individually, making the pooling algorithm 100% specific. In a population with 8% genital C. trachomatis prevalence, pooling by four would reduce costs by 39%. The model demonstrated that with a lower prevalence of 2%, pooling eight samples would reduce costs by 59%. Pooling urine samples for detection of C. trachomatis by LCR is sensitive, specific, and cost saving compared to testing individual samples.

scholarly journals Prevalence of mumps antibodies in the Israeli population in relation to mumps vaccination policy and incidence of disease

2007 ◽  
Vol 136 (5) ◽  
pp. 688-693 ◽  
Author(s):  
Kh. MUHSEN ◽  
Y. ABOUDY ◽  
E. MENDELSON ◽  
M. S. GREEN ◽  
D. COHEN
Keyword(s):  
High School Students ◽  
Herd Immunity ◽  
Population Sample ◽  
Vaccination Policy ◽  
Birth Cohorts ◽  
Mmr Vaccine ◽  
School Students ◽  
Military Recruits ◽  
Israeli Population ◽  
Mumps Antibodies

SUMMARYWe examined the prevalence of mumps antibodies in the Israeli population in relation to mumps vaccination policy and past and subsequent incidence of disease. The levels of specific IgG antibodies against mumps were tested in 3330 residual sera collected during 1997–1998 from an age-stratified population sample. Against the background of a consistent MMR vaccination coverage of >90%, the age- and sex-adjusted seropositivity to mumps was 77·0%. No significant differences between genders were found. Seropositivity in the 10–13 years age group, born just before the introduction of the MMR vaccine, was the lowest (59%). These birth cohorts were the target of an outbreak of mumps in 2005 that occurred among high-school students and military recruits. A trend of waning immunity was observed between the first and second vaccine doses. The seroepidemiological data demonstrate that immunity levels below the herd immunity threshold, along with social mixing and crowded conditions facilitated the occurrence of mumps outbreaks. Periodical serosurveys are an essential component in the evaluation of the vaccination policy against mumps.

Diagnosis of Neisseria gonorrhoeae infections in women by using the ligase chain reaction on patient-obtained vaginal swabs.

1997 ◽  
Vol 35 (8) ◽  
pp. 2129-2132 ◽  
Author(s):  
E W Hook ◽  
S F Ching ◽  
J Stephens ◽  
K F Hardy ◽  
K R Smith ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Chain Reaction ◽  
Ligase Chain Reaction ◽  
Vaginal Swabs

scholarly journals Genotyping of Chlamydia trachomatis in Urine Specimens Will Facilitate Large Epidemiological Studies

1998 ◽  
Vol 36 (10) ◽  
pp. 3077-3078 ◽  
Author(s):  
Servaas A. Morré ◽  
Robert Moes ◽  
Irene Van Valkengoed ◽  
Joan P. Boeke ◽  
Jacques T. M. van Eijk ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Rflp Analysis ◽  
Epidemiological Studies ◽  
Chain Reaction ◽  
Typing Method ◽  
Ligase Chain Reaction ◽  
Positive Urine ◽  
Urine Specimens

The serovars of Chlamydia trachomatis-positive urine specimens (n = 81; as detected by PCR and ligase chain reaction) were successfully analyzed in 94% of cases byomp1 PCR-based RFLP analysis. The use of urine specimens and this simple and sensitive typing method will greatly facilitate epidemiological studies of C. trachomatis serovar distribution in asymptomatic C. trachomatis infections in both females and males.

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