scholarly journals Performance of the Syva Direct Fluorescent Antibody Assay for Chlamydia in a Low-Prevalence Population

1993 ◽  
Vol 1 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Mark B. Reedy ◽  
Patricia J. Sulak ◽  
William B. McCombs III ◽  
Thomas J. Kuehl
Keyword(s):  
Tissue Culture ◽  
Fluorescent Antibody ◽  
Transmitted Disease ◽  
The United States ◽  
Current Data ◽  
Chlamydia Infection ◽  
Culture Methods ◽  
Predictive Values ◽  
Direct Fluorescent Antibody ◽  
Low Prevalence

Chlamydia trachomatisis the most common reportable sexually transmitted disease (STD) in the United States. In the 1980s, rapid diagnostic tests for chlamydia began to replace more cumbersome tissue culture methods. Current data on rapid antigen detection assays demonstrate acceptable sensitivity, specificity, and predictive values in populations with a high prevalence of chlamydia. Few studies report the performance of these assays in a low-prevalence obstetric and gynecologic (Ob/Gyn) population, This study compares the most commonly used direct fluorescent antibody (DFA) assay (Syva Microtrak) with tissue culture (TC) in a low-prevalence population. Endocervical specimens (775) were tested from women at risk for chlamydia infection, and the prevalence was found to be 7.7%. The DFA assay demonstrated a sensitivity of 80% and a specificity of 97% compared with TC. The positive and negative predictive values were 72% and 98%, respectively. The results of this study indicate that the Syva DFA assay lacks the sensitivity and positive predictive value for routine use in Ob/Gyn populations with a lowprevalence ofC. trachomatis.

scholarly journals Evaluation of the Biostar Chlamydia OIA Assay with Specimens from Women Attending a Sexually Transmitted Disease Clinic

1998 ◽  
Vol 36 (8) ◽  
pp. 2183-2186 ◽  
Author(s):  
Mitchell S. Pate ◽  
Paula B. Dixon ◽  
Kim Hardy ◽  
Mark Crosby ◽  
E. W. Hook
Keyword(s):  
Cell Culture ◽  
Chlamydia Trachomatis ◽  
Fluorescent Antibody ◽  
Transmitted Disease ◽  
The United States ◽  
Chlamydia Screening ◽  
Test Results ◽  
Screening Assay ◽  
Predictive Values ◽  
Sexually Transmitted

Chlamydia trachomatis infections are the most prevalent sexually transmitted diseases (STDs) in the United States. In acute-care settings such as clinics and emergency rooms, a desirable chlamydia screening assay should exhibit good sensitivity and good specificity and should provide test results while the patient is still present. The Biostar Chlamydia OIA (Biostar, Inc., Boulder, Colo.) is an optical immunoassay (OIA) that provides test results in less than 30 min and that uses a test format that allows office-based testing. This assay is performed entirely at room temperature without the need for rotators or other specialized equipment. The goal of this study was to compare the performance of the Biostar Chlamydia OIA for the detection of C. trachomatis with the performance of cell culture, direct fluorescent-antibody (DFA) assay (Syva MicroTrak; Syva Co., Palo Alto, Calif.), and PCR (Roche Amplicor Chlamydia trachomatis; Roche, Branchburg, N.J.) for the detection ofC. trachomatis infections in women attending an urban STD clinic. For calculations of relative test performance (sensitivity, specificity, and positive and negative predictive values), patient specimens that yielded positive results by two or more of the four assays (cell culture, DFA assay, PCR, and OIA) were classified as “true infections.” By these criteria, 42 of 306 total specimens were classified as positive for C. trachomatis (positive prevalence, 13.7%), 11 (3.6%; 10 by PCR and 1 by DFA assay) were positive by a single assay, and 253 (82.7%) were negative by all four tests. All culture-positive specimens were also positive by at least one other assay. Among the culture-negative specimens, 14 (5%) specimens were positive by two of the three non-culture-based assays used. By using the criterion that positivity by at least two of the tests indicated a true infection, the relative sensitivities were as follows: culture and PCR, 92.9% each; Biostar Chlamydia OIA, 73.8%; and DFA assay, 59.5%.

scholarly journals Comparison of Automated Quantitative Reverse Transcription-PCR and Direct Fluorescent-Antibody Detection for Routine Rabies Diagnosis in the United States

2015 ◽  
Vol 53 (9) ◽  
pp. 2983-2989 ◽  
Author(s):  
Michelle Dupuis ◽  
Scott Brunt ◽  
Kim Appler ◽  
April Davis ◽  
Robert Rudd
Keyword(s):  
United States ◽  
Reverse Transcription ◽  
Gold Standard ◽  
Fluorescent Antibody ◽  
The United States ◽  
Pcr Assay ◽  
Qrt Pcr ◽  
Reverse Transcription Pcr ◽  
Direct Fluorescent Antibody ◽  
Rabies Diagnosis

Rabies virus found worldwide and prevalent throughout the United States continues to be a public health concern. Direct-fluorescent antibody (DFA) detection remains the gold standard for rabies virus diagnostics. Assessing the utility of a high-throughput molecular platform such as the QIAsymphony SP/AS, in conjunction with quantitative reverse transcription-PCR (qRT-PCR), to augment or potentially replace the DFA test, was the focus of this project. Here we describe a triplex qRT-PCR assay, including assembly and evaluation for sensitivity, specificity, and ability to detect variants. Additionally, we compared the qRT-PCR assay to the gold standard direct fluorescent-antibody test. More than 1,000 specimens submitted for routine rabies diagnosis were tested to directly compare the two methods. All results were in agreement between the two methods, with one additional specimen detected by qRT-PCR below the limits of the DFA sensitivity. With the proper continued validation for variant detection, molecular methods have a place in routine rabies diagnostics within the United States.

scholarly journals Seasonal Cholera Caused by Vibrio cholerae Serogroups O1 and O139 in the Coastal Aquatic Environment of Bangladesh

2006 ◽  
Vol 72 (6) ◽  
pp. 4096-4104 ◽  
Author(s):  
Munirul Alam ◽  
Nur A. Hasan ◽  
Abdus Sadique ◽  
N. A. Bhuiyan ◽  
Kabir U. Ahmed ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Ecological Study ◽  
Enrichment Culture ◽  
Fluorescent Antibody ◽  
Blot Hybridization ◽  
Culture Methods ◽  
Lack Of Information ◽  
Direct Fluorescent Antibody ◽  
El Tor

ABSTRACT Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139 was carried out in two coastal areas, Bakerganj and Mathbaria, Bangladesh, where cholera occurs seasonally. The results of a biweekly clinical study (January 2004 to May 2005), employing culture methods, and of an ecological study (monthly in Bakerganj and biweekly in Mathbaria from March 2004 to May 2005), employing direct and enrichment culture, colony blot hybridization, and direct fluorescent-antibody methods, showed that cholera is endemic in both Bakerganj and Mathbaria and that V. cholerae O1, O139, and non-O1/non-O139 are autochthonous to the aquatic environment. Although V. cholerae O1 and O139 were isolated from both areas, most noteworthy was the isolation of V. cholerae O139 in March, July, and September 2004 in Mathbaria, where seasonal cholera was clinically linked only to V. cholerae O1. In Mathbaria, V. cholerae O139 emerged as the sole cause of a significant outbreak of cholera in March 2005. V. cholerae O1 reemerged clinically in April 2005 and established dominance over V. cholerae O139, continuing to cause cholera in Mathbaria. In conclusion, the epidemic potential and coastal aquatic reservoir for V. cholerae O139 have been demonstrated. Based on the results of this study, the coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae.

Chlamydia and Suspected Sexual Abuse

PEDIATRICS ◽  
1988 ◽  
Vol 81 (4) ◽  
pp. 601-602
Author(s):  
LAWRENCE S. NEINSTEIN ◽  
C. DANIEL FUSTER
Keyword(s):  
Sexual Abuse ◽  
Child Abuse ◽  
Young Child ◽  
Sensitivity And Specificity ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Prevalence Rates ◽  
Perinatal Infection ◽  
Direct Fluorescent Antibody ◽  
Low Prevalence

In Reply.— We thank Dr Hammerschlag for her thoughtful comments. We wholeheartedly agree with her about the use of cultures in the setting of suspected sexual abuse. As other studies have indicated, the sensitivity and specificity of the direct fluorescent antibody test are too low in a population with low prevalence rates such as a population with suspected child abuse. We also agree with Dr Hammerschlag about the possibility of perinatal infection in a young child.

scholarly journals Toxigenic Vibrio cholerae in the Aquatic Environment of Mathbaria, Bangladesh

2006 ◽  
Vol 72 (4) ◽  
pp. 2849-2855 ◽  
Author(s):  
Munirul Alam ◽  
Marzia Sultana ◽  
G. Balakrish Nair ◽  
R. Bradley Sack ◽  
David A. Sack ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Fluorescent Antibody ◽  
Culture Methods ◽  
Viable But Nonculturable ◽  
Large Numbers ◽  
Direct Fluorescent Antibody ◽  
Nonculturable Cells ◽  
Seasonal Epidemics

ABSTRACT Toxigenic Vibrio cholerae, rarely isolated from the aquatic environment between cholera epidemics, can be detected in what is now understood to be a dormant stage, i.e., viable but nonculturable when standard bacteriological methods are used. In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic periods. Biweekly environmental surveillance for V. cholerae was carried out in Mathbaria, an area of cholera endemicity adjacent to the Bay of Bengal, with the focus on V. cholerae O1 and O139 Bengal. A total of 297 samples of water, phytoplankton, and zooplankton were collected between March and December 2004, yielding eight V. cholerae O1 and four O139 Bengal isolates. A combination of culture methods, multiplex-PCR, and direct fluorescent antibody (DFA) counting revealed the Mathbaria aquatic environment to be a reservoir for V. cholerae O1 and O139 Bengal. DFA results showed significant clumping of the bacteria during the interepidemic period for cholera, and the fluorescent micrographs revealed large numbers of V. cholerae O1 in thin films of exopolysaccharides (biofilm). A similar clumping of V. cholerae O1 was also observed in samples collected from Matlab, Bangladesh, where cholera also is endemic. Thus, the results of the study provided in situ evidence for V. cholerae O1 and O139 in the aquatic environment, predominantly as viable but nonculturable cells and culturable cells in biofilm consortia. The biofilm community is concluded to be an additional reservoir of cholera bacteria in the aquatic environment between seasonal epidemics of cholera in Bangladesh.

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