Feasibility and Short-Term Impact of Linked Education and Urine Screening Interventions for Chlamydia and Gonorrhea in Male Army Recruits

OBJECTIVE

The objective of this study was to assess the feasibility of an intervention for sexually transmitted diseases (STDs) and a screening program for Chlamydia trachomatis and Neisseria gonorrhoeae infections in male Army recruits.

GOALS

The goals of this study were to identify and treat chlamydia and gonorrhea infections in recruits, assess their perceptions of risk, and increase their STD knowledge and behavioral intentions.

STUDY DESIGN

Volunteers (n = 3911) entering basic training (July 1999-June 2000) at Fort Jackson, South Carolina, attended an educational intervention, completed pre- and post-questionnaires, and provided a urine specimen for chlamydia and gonorrhea screening by nucleic acid amplification testing.

RESULTS

Chlamydia and gonorrhea prevalences were 4.7% and 0.4%, respectively. The mean STD knowledge score, intent to use condoms, and confidence in using condoms correctly increased (P <0.001). Participants reported increased risk perception and considered the educational program valuable (96.9%) and a learning experience (94.6%).

CONCLUSIONS

A linked educational and screening program is feasible and acceptable in male Army recruits.

Comparison of three nucleic acid amplification tests for detection of Chlamydia trachomatis in urine specimens

Traditionally, culture and immunoassays have been performed for the detection of sexually transmitted diseases, including Chlamydia trachomatis. However, these assays may often require invasive specimen collection methods, such as female cervical and male urethral swabs. Recently, nucleic acid amplification tests (NAATs) have been approved for testing for the presence of C. trachomatis in urine samples. Our objective was to compare the sensitivities and specificities of C. trachomatis detection in urine samples with three NAATs: the Abbott LCx (LCx), BD ProbeTec ET (ProbeTec), and Gen-Probe APTIMA Combo 2 (AC2). Urine specimens (n = 506) were collected from both symptomatic and asymptomatic males and females from various high school health clinics. Specimens were tested for C. trachomatis with the three NAATs, and a true-positive result was defined as any two positive NAATs. The C. trachomatis prevalence was 14.8% (75 of 506 samples). Of the 75 urine samples defined as true positives, LCx detected 72, ProbeTec 72, and AC2 detected 75. The sensitivities of LCx, ProbeTec, and AC2 for C. trachomatis detection were 96.0, 96.0, and 100%, and the specificities were 99.1, 100, and 98.8%, respectively. Four of five samples that were positive with AC2 and negative with LCx and ProbeTec were found to be positive with an alternative target TMA-based NAAT, APTIMA C. trachomatis, suggesting that they may have been true positives. Two of four uniquely positive LCx samples available for subsequent testing were both found to be positive by Roche PCR. We found that the LCx, ProbeTec, and AC2 NAATs are highly sensitive and specific methods for the detection of C. trachomatis in urine specimens and can be recommended for noninvasive screening of C. trachomatis in urine.

Is Chlamydia pneumoniae infection associated with stroke in children with sickle cell disease?

BACKGROUND

Stroke is often a devastating complication of sickle cell disease (SCD). Most children with SCD-related stroke have stenotic and occlusive disease of cerebral blood vessels due to intimal hyperplasia. This hyperplasia is hypothesized to result from an inflammatory response similar to that in atherosclerosis and has been attributed to infection by Chlamydia pneumoniae.

OBJECTIVE

To determine whether C pneumoniae infection is associated with stroke and cerebrovascular disease, including transient ischemic attacks and abnormal transcranial Doppler examinations, in children with SCD.

METHODS

Children with SCD on chronic transfusion due to a history of stroke, transient ischemic attack, or abnormal transcranial Doppler; children with SCD without stroke; healthy controls; and children being transfused for other reasons were enrolled. Peripheral blood and nasopharyngeal (NP) swab specimens were collected from all patients. In patients on transfusion, pretransfusion specimens and samples from the unit of packed red blood cells being transfused were obtained. Peripheral blood monocytic cells (PBMCs) and NP swab specimens were cultured for C pneumoniae in HEp-2 cells. C pneumoniae polymerase chain reaction was performed on PBMCs with a nested touch-down method with primers from the omp-1gene (in duplicate) and a second real-time polymerase chain reaction by using 16S ribosomal RNA primers.

RESULTS

C pneumoniae DNA was detected in the PBMCs of 1 of 14 (7.1%) children with SCD on chronic transfusion, 1 of 10 (10%) sickle cell controls, 1 of 10 (10%) healthy controls, and none of the 5 children receiving chronic transfusion for other reasons. It was not detected in specimens from transfusion units. One child with SCD and stroke, 1 sickle cell control, and 1 transfusion control had positive NP cultures for C pneumoniae. C pneumoniae DNA was not detected in their PBMCs, and all 3 children were asymptomatic. C pneumoniae was not detected by culture of PBMCs from any of the patients after 7 passages.

CONCLUSION

Stroke in children with SCD does not seem to be associated with C pneumoniae infection in our population.

Cost-Effectiveness Analysis of Screening Adolescent Males for Chlamydia On Admission to Detention

BACKGROUND

Chlamydia trachomatis infections can lead to serious and costly sequelae. Because chlamydia is most often asymptomatic, many infected youth do not seek testing. Entry to a detention system provides an opportunity to screen and treat many at-risk youth. GOAL The goal of this study was to determine the cost-effectiveness of screening male youth for chlamydia on entry to detention.

STUDY DESIGN

Incremental cost-effectiveness of 3 chlamydia screening strategies was compared for a hypothetical cohort of 4000 male youth per year: 1) universal chlamydia screening using a urine-based nucleic acid amplification test (NAAT), 2) selective NAAT screening of urine leukocyte esterase (LE)-positive urines, and 3) no screening. The model incorporated programmatic costs of screening and treatment and medical cost savings from sequelae prevented in infected males and female partners. The analysis was conducted from the healthcare system perspective.

RESULTS

Chlamydia prevalence in the sampled population of 594 was 4.8%, and the average number of female sexual partners/infected male was 1.6. Universal NAAT screening was the most cost-effective strategy, preventing 37 more cases of pelvic inflammatory disease (PID) and 3 more cases of epididymitis than selective screening and saving an additional 24,000 dollars. The analysis was sensitive to NAAT cost, LE sensitivity, rate of PID development, PID sequelae cost, and number of female partners. Universal screening remained the most cost saving for prevalence as low as 2.8% or higher.

CONCLUSIONS

Universal chlamydia screening of adolescent males on entry to detention was the most cost-effective strategy. Savings are primarily the result of the prevention of PID in recent and future partners of index males. Screening detained male youth using a urine-based NAAT provides a public health opportunity to significantly reduce chlamydia infections in youth at risk for sexually transmitted diseases.

Preference among female Army recruits for use of self-administrated vaginal swabs or urine to screen for Chlamydia trachomatis genital infections

BACKGROUND

Use of self-administered vaginal swabs (SAS) for the detection of Chlamydia trachomatis by nucleic acid amplification tests simplifies specimen collection and transport, especially for women in nonclinical settings.

GOAL

We investigated the preference and comfort level of military women for the collection of SAS, compared with urine, for the diagnosis of genital chlamydial infections.

STUDY DESIGN

During March through August 1999, female Army recruits in basic training at Fort Jackson, South Carolina, were invited to participate in the study. Participants were requested to complete a questionnaire after providing both first-void urine (FVU) and SAS specimens. Participant characteristics, preferences, and comfort levels were assessed using multivariate logistic regression.

RESULTS

From 4496 eligible female recruits, 1403 (31%) completed questionnaires and 1382 provided both specimens; 11.8% (166 of 1403) of participants were infected with chlamydia. The relative sensitivity and specificity of the C. trachomatis Ligase Chain Reaction test on SAS in 1382 matched pairs was 81.1% and 98.6%, respectively, using the test result on urine specimens as the comparison standard. Most of the participants (90.8%) reported that they felt comfortable collecting the FVU specimen, and 69.6% indicated that they felt comfortable collecting SAS. Either specimen collection type received high acceptability at home and in the field, and more women reported that they would collect FVU than reported they would collect SAS in the future (in the field: FVU: 79.4%, SAS: 68.8%, P <0.001); at home: FVU: 90.9%, SAS: 82.9%, P <0.001). When questioned about ease of use, 60.4% of women reported that urine was the easier method. Preferences for SAS were associated with being white and having had sexual risk behaviors in the past 3 months.

CONCLUSION

A study of preferences for urine versus self-administered vaginal swabs for the detection of C. trachomatis in military women showed that women generally found SAS acceptable. SAS should be a feasible alternative to urine collection in situations in which specimen storage or transport is an issue.

Sustained high prevalence of Chlamydia trachomatis infections in female army recruits

BACKGROUND

Chlamydia trachomatis infections are prevalent among young sexually active females, have serious sequelae, and are mostly asymptomatic. Screening and treatment of infected females has been demonstrated to prevent sequelae such as pelvic inflammatory disease.

GOAL

To assess prevalence and risk factors for chlamydia infection in US Army female recruits, whether these changed over time, and to examine variables contributing to any observed patterns.

STUDY DESIGN

Prevalence study of 23,010 non-healthcare-seeking female Army recruits enrolled in a chlamydia screening program at Fort Jackson, SC, from January 1996 through June 1999. Each of the 4-year cohorts was examined separately for prevalence and risk factors.

MAIN OUTCOME MEASURES

Urine-based testing for C trachomatis by ligase chain reaction was used to determine prevalence, and questionnaires were used to collect demographic and risk information. State home of record for each recruit was transformed into Public Health reporting region: West, Midwest, South, Northeast, and Territories.

RESULTS

Prevalence for all years was 9.51%, but a progressive increase from 8.51% to 9.92% occurred over the course of study (P=0.018). The proportion of individuals reporting specific risk factors during the 90 days preceding the study generally decreased over time. In a regression model, significant risk factors for infection included black race, age 25 years or younger, home-of-record from the South, being screened during years 3 and 4 of the study, more than one sex partner, a new sex partner, and history of any sexually transmitted disease. Condom use was protective. In another model controlling for age and home-of-record from the South, being screened in years 2, 3, and 4 of the study were significantly predictive for being chlamydia positive.

CONCLUSION

A high and slightly increasing prevalence of C trachomatis infection was observed among young females entering the military over 4 consecutive years. Young age, black race, home-of-record from the South, more than one sex partner, a new sex partner, condom use, and a history of having a sexually transmitted disease were correlates of chlamydia infection. Sustained high rates of C trachomatis infection in this population provide clear justification for a chlamydia control program for young women entering the Army consisting of screening at entry on the basis of age and possibly home-of-record together with continued periodic rescreening.

SUMMARY

A study of 23,010 female Army recruits demonstrated that a high prevalence of C trachomatis was sustained during 4 years of observation. Year of study, young age, and being from the South were significant predictors of infection.

Use of urine polymerase chain reaction to define the prevalence and clinical presentation of Trichomonas vaginalis in men attending an STD clinic

OBJECTIVE

To determine the prevalence and clinical features of Trichomonas vaginalis (TV) infection in men.

METHODS

Men attending a public STD clinic in Baltimore, Maryland, were evaluated between March and July 2000. Clinicians recorded a standardised history and clinical examination. Urethral swab specimens were collected for Gram stain and Neisseria gonorrhoeae culture. First fraction urine samples were evaluated with TV culture and chlamydia and TV polymerase chain reaction (PCR). True positive TV was defined as a positive TV culture or a positive TV PCR confirmed with a second primer set.

RESULTS

355 men were evaluated in 363 visits. The prevalence of gonorrhoea, TV, and chlamydia were 19%, 13%, and 11%, respectively. In men over 28 years, the prevalence of TV was significantly higher than chlamydia. Age and urethritis by Gram stain were associated with a positive result on TV culture (p=0.03 and p=0.02, respectively) but not associated with TV infection as defined by a positive TV culture or a confirmed TV PCR. Discharge or dysuria was reported in 47% and 22% of men with TV, respectively.

CONCLUSIONS

TV prevalence in an urban STD clinic setting was high. Older age and urethritis were not significantly associated with TV infection as defined by a positive TV culture or a confirmed TV PCR.

Female prisoners' preferences of collection methods for testing for Chlamydia trachomatis and Neisseria gonorrhoeae infection

BACKGROUND

There is an increasing reliance on noninvasive techniques to collect specimens for the detection of sexually transmitted infections. The acceptability of these methods among the general population has been explored, but little is known about their acceptability among women confined in prison.

GOAL

The goal was to compare female prisoners' preferences for collection of specimens (self-collected vaginal swab specimens, urine collection, or pelvic examination) for detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

STUDY DESIGN

A cross-section of inmates in a large federal prison provided urine samples and self-collected vaginal swab specimens. Women then completed a questionnaire regarding the ease of each method and their preferences for future specimen collection.

RESULTS

A total of 535 women between the ages of 18 and 52 years (median = 33) participated in the study. More than half of the participants (57%) reported no difference between urine and swab in terms of ease of collection. Approximately 30% of participants said they would prefer to give a swab specimen in the future rather than collect urine (21%), but nearly half of the women expressed no preference for one method over the other. Most participants (60%) expressed a preference for providing a self-collected swab specimen rather than having a pelvic examination (23%), but nearly 17% expressed a preference for one over the other.

CONCLUSION

The study population of female federal prisoners expressed no aversion to the self-collection of either vaginal swab or urine specimens for STD testing. A majority of participants expressed a preference for noninvasive techniques rather than a pelvic examination.

Surveillance of Chlamydia trachomatis and Neisseria gonorrhoeae infections in women in detention in Baltimore, Maryland

BACKGROUND

In conjunction with a program to expand syphilis and HIV infection services, women were also offered screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) during intake at the Baltimore Women's Detention Center.

GOAL

The goal was to assess the effectiveness of a routine screening program for CT and GC in women in a detention setting. The association among infection, race, and area of residence was also explored.

STUDY DESIGN

CT and GC prevalences were determined and analyzed by demographic data, including zipcode, for 1,858 women enrolled over a 48-week period. Informed consent was obtained, and infections were detected with use of urine samples tested by ligase chain reaction.

RESULTS

Overall, the population had prevalence rates of 5.9% (109/1,858) and 3.4% (63/1,858) for CT and GC respectively. Among whites, CT and GC prevalences were 9.0% (29/323) and 8.7% (28/323), respectively. Among African Americans the prevalence rates were 5.1% (77/1,510) and 2.3% (34/1,510) for CT and GC, respectively. White women <25 years of age were associated with the highest CT and GC prevalences, at 20.0% (13/65) and 13.9% (9/65), respectively. African American women <25 years of age also were associated with the highest CT and GC prevalences, at 13.9% (24/173) and 5.8% (10/173), respectively. Multivariate analysis of risk factors and demographic data indicated that ages <25 years and 25 to 34 years, white race, and certain zipcodes of residence were risk factors for infection.

CONCLUSION

This study illustrated that urine-based screening for CT and GC is feasible in detention settings and can be productive in high-prevalence areas. Geographic analysis demonstrated no definitive relationship among race, infection, and area of residence, although it did demonstrate clustering of infected individuals and could be useful in future interventions. These findings demonstrated the need for implementing screening programs for sexually transmitted infections in detention centers.

Performance of the APTIMA Combo 2 assay for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in female urine and endocervical swab specimens

The greater sensitivity of nucleic acid amplification tests (NAATs) for Chlamydia trachomatis and Neisseria gonorrhoeae permits the use of urine and other noninvasive specimens, which can increase the reach and decrease the costs of public health screening programs aimed at controlling these infections. This study evaluated the performance of the APTIMA Combo 2 assay, a multiplex assay based on the transcription-mediated amplification reaction, for the simultaneous detection of both pathogens in endocervical swab and urine specimens from females. Combo 2 assay results were compared with patient infected status, which were available by using other commercial NAATs. Sensitivity and specificity for C. trachomatis were 94.2 and 97.6%, respectively, in swabs and 94.7 and 98.9%, respectively, in first-catch urine (FCU). Sensitivity and specificity for N. gonorrhoeae were 99.2 and 98.7%, respectively, in swabs and 91.3 and 99.3%, respectively, in FCU. The assay reliably detected both infections in coinfected patients. The Combo 2 assay can be recommended for use with endocervical swab and urine specimens from females, especially for screening tests for asymptomatic women in sexually transmitted disease surveillance programs. This Food and Drug Administration-cleared assay can be a useful tool in efforts to reduce the prevalence and incidence of C. trachomatis and N. gonorrhoeae infections in sexually active women and to prevent their costly and serious sequelae.

Reliability of nested PCR for detection of Chlamydia pneumoniae DNA in atheromas: results from a multicenter study applying standardized protocols

The present multicenter study was designed to find explanations for the discrepancies in the reported rates of detection of Chlamydia pneumoniae DNA in endarterectomy specimens. Coded identical sets of (i) a C. pneumoniae DNA dilution series (panel 1; n = 10), (ii) spiked control tissue specimens (panel 2; n = 10 specimens, including 5 negative controls), and (iii) endarterectomy specimens (panel 3; 15 atheromas, 5 negative controls) were analyzed at four laboratories by three standardized DNA extraction methods in each laboratory and a nested touchdown PCR protocol targeting the ompA gene of C. pneumoniae. Panel 1 samples were correctly identified as positive to levels of 0.3 inclusion-forming units (IFU)/PCR mixture (100%) and 0.03 IFU/PCR mixture (50%). All negative controls were correctly reported as negative. Panel 2 samples were identified as C. pneumoniae positive to levels of 0.01 IFU/PCR mixture (100%) and 0.005 IFU/PCR mixture (91%), independent of the DNA extraction method used, and only one false-positive result was reported. For panel 3 samples, 5 of 240 (2%) analyses (in which DNA extractions and PCR were performed at the same laboratory) were positive; the positive specimens were from three endarterectomy specimens and two negative controls. After exchange of DNA extracts between laboratories, 13 of 15 atheroma samples were C. pneumoniae DNA positive in at least 1 of a series of 48 analyses per atheroma sample; however, the overall positivity rate did not exceed 5% (33 of 720 analyses) and therefore was lower than that for the negative controls (8%; 19 of 240 analyses). Not a single positive result could be achieved when all panel 3 extracts (n = 240 analyses) were reamplified by a 16S rRNA PCR followed by hybridization with a C. pneumoniae-specific probe. Statistical analyses demonstrated that positive results did not occur in an independent and random fashion and could most likely be explained by amplicon carryover at the nested PCR level as well as amplicon introduction during DNA extraction, but not by the patterns of distribution of very low target levels or a certain DNA extraction protocol. The results of studies by nested PCR for detection of the prevalence of C. pneumoniae will always be questionable.

Detection of bacteremia in emergency department patients at risk for infective endocarditis using universal 16S rRNA primers in a decontaminated polymerase chain reaction assay

Prompt definitive diagnosis of acute bacterial endocarditis in febrile injection drug users (IDUs) remains problematic because of delays associated with blood culture. Rapid detection of bacteremia by polymerase chain reaction (PCR) by use of "universal" primers has been hampered by background bacterial contamination. Broad-range eubacterial primers selected from the 16S rRNA gene were used in a PCR assay coupled with a simple pre-PCR decontamination step. All PCR reagents were pretreated with the restriction enzyme AluI, which has multiple digestion sites in the amplicon but none in the primer sets. When 4 different bacterial species were spiked into healthy human blood specimens, the assay identified each pathogen with an analytic sensitivity of 5 bacteria/PCR reaction. A clinical trial with 51 febrile IDUs revealed that PCR had a sensitivity and specificity of 86.7% and 86.9%, respectively, versus blood culture. Importantly, all (8/8) patients with blood culture-positive infective endocarditis were determined to be positive by PCR. This assay provides a promising diagnostic for rapid identification of bacteremia, particularly valuable in acute care settings.

Quantitative multiprobe PCR assay for simultaneous detection and identification to species level of bacterial pathogens

We describe a novel adaptation of the TaqMan PCR assay which potentially allows for highly sensitive detection of any eubacterial species with simultaneous species identification. Our system relies on a unique multiprobe design in which a single set of highly conserved sequences encoded by the 16S rRNA gene serves as the primer pair and is used in combination with both an internal highly conserved sequence, the universal probe, and an internal variable region, the species-specific probe. A pre-PCR ultrafiltration step effectively decontaminates or removes background DNA. The TaqMan system described reliabAly detected 14 common bacterial species with a detection limit of 50 fg. Further, highly sensitive and specific pathogen detection was demonstrated with a prototype species-specific probe designed to detect Staphylococcus aureus. This assay has broad potential in the clinical arena for rapid and specific diagnosis of infectious diseases.

Trichomonas vaginalis polymerase chain reaction compared with standard diagnostic and therapeutic protocols for detection and treatment of vaginal trichomoniasis

Wet preparation has limited sensitivity for diagnosis of Trichomonas vaginalis (TV) infection. An observational study of 337 women was conducted to evaluate a new polymerase chain reaction (PCR) test for TV. The sensitivities of wet preparation and TV culture were 52% (95% confidence interval [CI], 41-62) and 78% (95% CI, 69-86), respectively. TV PCR had a sensitivity of 84% (95% CI, 75-90) and a specificity of 94% (95% CI, 90-97). Metronidazole was provided to 67 (69%) of 97 women with TV because of TV on wet preparation, exposure to TV, or a diagnosis of bacterial vaginosis or pelvic inflammatory disease; however, if TV PCR had been used for diagnosis, 81 (84%) of 97 women with TV would have been treated (P=.02). TV is significantly undertreated using standard algorithms for metronidazole therapy. Given the association of trichomoniasis with perinatal morbidity and HIV transmission, women in high-risk groups may benefit from TV PCR.

Is Chlamydia pneumoniae found in spinal fluid samples from multiple sclerosis patients? Conflicting results

Cerebrospinal fluid samples from controls and patients with multiple sclerosis (MS) were split and sent to laboratories with different experiences for the detection of Chlamydia pneumoniae by polymerase chain reaction. Vanderbilt investigators identified C. pneumoniae in the majority of patients with MS and uncommonly in controls. Laboratories at Johns Hopkins University, University of Umeå, and the Centers for Disease Control and Prevention did not identify C. pneumoniae in any of the samples. Conflicting reports of C. pneumoniae detection in the some samples from patents with MS highlight the need to exchange detection techniques among laboratories involved in this controversy.

Screening women in jails for chlamydial and gonococcal infection using urine tests: feasibility, acceptability, prevalence, and treatment rates

BACKGROUND

Women entering jails are at high risk for sexually transmitted diseases; however, screening for chlamydial and gonococcal infection is not routinely performed in most jails. New urine tests have made it easier to screen for these infections in nonclinical settings.

GOAL

The feasibility and acceptability of urine-based screening for women entering jails and the prevalence of and treatment rates for chlamydial and gonococcal infections were determined.

STUDY DESIGN

Women entering jails in Chicago, Illinois; Birmingham, Alabama; and Baltimore, Maryland, who signed consent forms were tested for chlamydial and gonococcal infection by means of the urine ligase chain reaction assay. Those testing positive were treated in jail; health department staff members attempted to contact those already released.

RESULTS

Most women who were approached agreed to be tested (range, 87-98%, depending on city), and most of these women provided a specimen (range, 92-100%). Among 5364 women aged 16 to 75 years who were tested, the prevalence of chlamydial and gonococcal infections was high, especially among those <25 years of age (range, 15.3-21.5% for chlamydial infection and 8.2-9.2% for gonorrhea, depending on city). The majority of women testing positive were treated in jail or outside of jail (61-85%).

CONCLUSIONS

Screening women in jails for chlamydial and gonococcal infection with urine tests is feasible, is acceptable to most women, and leads to detection and treatment of many infections. Routine screening should reduce medical complications in this population and should prevent transmission in the community, given that many women are soon released.

Temporal arteritis and Chlamydia pneumoniae: failure to detect the organism by polymerase chain reaction in ninety cases and ninety controls

OBJECTIVE

To examine the reported correlation between the presence of Chlamydia pneumoniae in temporal artery biopsy specimens and the diagnosis of temporal arteritis (TA).

METHODS

Among 90 possible cases of TA identified at our institution between 1968 and 2000, 79 of the positive biopsy specimens (88%) demonstrated giant cells and the other 11 cases (12%) had other histopathologic features compatible with TA; by chart review, all 90 patients were confirmed to have met the American College of Rheumatology classification criteria for TA. Controls had negative temporal artery biopsy specimens during the same 32-year time period and their postbiopsy disease courses were not compatible with TA. Controls were matched with each case by sex, year of biopsy, and age within 10 years. The biopsy specimens from all cases and controls were reevaluated and readings were confirmed in a masked manner by an experienced eye pathologist. Polymerase chain reaction (PCR) analyses for C pneumoniae were performed on the 180 samples using 2 different sets of PCR primers (which target 2 different genes). A primer set targeting the ompA gene (CP1-CP2/CPC-CPD) was used to perform a nested PCR, followed by confirmation of the findings with primers targeting the 16S ribosomal RNA (rRNA) gene (Cpn90/Cpn91) in a touchdown-enzyme time-release PCR. We used positive and negative controls, as well as controls made from infected and noninfected HEp-2 cells, suspended in a formalin-fixed, paraffin-embedded matrix.

RESULTS

Seventy-six percent of the 180 cases and controls were women. The mean age of the cases was 72.0 years (range 53-90), and that of the controls was 70.4 years (range 51-86). Eighty percent of the control samples were obtained by temporal artery biopsy performed within 1 year of the biopsies performed on the matched cases. Using the CP1-CP2/CPC-CPD primer set, only 1 TA case sample (1% of all case samples) was positive for the ompA gene. One control sample was also positive using these primers. With the Cpn90/Cpn91 primers, none of the cases and none of the controls were positive for the 16S rRNA gene.

CONCLUSION

The results of this study using sensitive and specific PCR analyses do not support a role for C pneumoniae in the pathogenesis of TA.

The Use of Urine and Self-obtained Vaginal Swabs for the Diagnosis of Sexually Transmitted Diseases

Studies have reported that self-collected specimens, such as urine or vaginal swabs, can be successfully used to diagnose sexually transmitted infections when they are used with nucleic acid amplification assays. This eliminates the necessity for a clinician-performed pelvic examination for women, or a urethral swab for men, for sample collection. These nucleic acid amplification assays used with self-collected specimens are highly sensitive and specific, and their use may be extended to broad nonclinic screening venues, where their use can augment public health programs designed to control the epidemic of sexually transmitted diseases.

Evaluation of dry and wet transported intravaginal swabs in detection of Chlamydia trachomatis and Neisseria gonorrhoeae infections in female soldiers by PCR

Screening women for sexually transmitted diseases (STD) in nonclinic settings is highly desirable because many infections are asymptomatic. This is especially true for military women, for whom logistical, social, and other job-related obstacles present barriers to accessing medical care. We assessed the accuracy of intravaginal swabs transported by mail in a wet versus a dry state for PCR (Amplicor CT/NG test) detection of chlamydia and gonorrhea infections in a cross-sectional study of 793 active-duty military women attending an STD clinic. PCR tests of vaginal swabs (wet and dry) were compared to local clinical methods used on cervical swabs. Standard wet vaginal swab PCR testing detected more chlamydia (11.6%) than cervical enzyme immunoassay (9.3%). For detection of chlamydia using wet swabs, the sensitivity and specificity compared with adjudicated true positives were 94.6% (87 of 92) and 99.3% (696 of 701), respectively. Comparing dry swabs to true-positives for chlamydia, the sensitivity was 91.3% (84 of 92) and the specificity was 99.3% (696 of 701). Standard wet vaginal swab PCR detected more gonorrhea (3.3%) than routine cervical culture (2.1%). The sensitivity and specificity of PCR testing of wet swabs compared to true-positives (infected patients) were 96.3% (26 of 27) and 98.2% (752 of 766) for gonorrhea, respectively. For gonorrhea, the sensitivity and specificity of dry swabs compared to true-positives (infected patients) were 88.9% (24 of 27) and 98.3% (753 of 766), respectively. PCR testing of wet and dry transported intravaginal swabs to detect chlamydia and gonorrhea infections was an accurate diagnostic method for military women.

Hospitalization rates in female US Army recruits associated with a screening program for Chlamydia trachomatis

BACKGROUND

A volunteer program to test non-healthcare-seeking women for genital Chlamydia trachomatis infection was instituted at the US Army's largest basic training center and evaluated for its effectiveness in reducing sequelae.

GOAL

To compare hospitalization rates between women with positive test results for C trachomatis and those with negative results, and between women tested and those not tested for C trachomatis.

STUDY DESIGN

For this study, 28,074 women who entered the Army in 1996 and 1997 were followed for hospitalizations through December 1998. Of these women, 7053 were tested for C trachomatis, and 21,021 were not screened. Hospital admissions were calculated per person-year, and adjusted relative risks were determined.

RESULTS

The overall prevalence of C trachomatis in the screened group was 9.1%. The relative risk of hospitalization for pelvic inflammatory disease in the screened cohort was 0.94 (95% CI, 0.69-1.29), as compared with those not screened. The relative risk of hospitalization for any reason was 0.94 (95% CI, 0.90-0.99). Among women screened, no difference was found in pelvic inflammatory disease hospitalizations between women with positive test results who were being treated for C trachomatis and those with negative test results.

CONCLUSIONS

The investigated C trachomatis intervention program for female Army recruits was associated with a lower overall hospitalization rate in screened volunteers, as compared with unscreened women. The pelvic inflammatory disease hospitalization rate in women with C trachomatis who were screened and treated was similar to that observed in uninfected women.

Features of Chlamydia trachomatis and Neisseria gonorrhoeae infection in male Army recruits

Non-health care-seeking male United States Army recruits were tested for Chlamydia trachomatis (n=2245) and Neisseria gonorrhoeae (n=884), using a urine ligase chain reaction test to determine prevalence and potential risk factors for infection. The prevalence of chlamydial infection was 5.3%. Black race, a new sex partner, a history of trichomonas, and the presence of symptoms were associated with chlamydial infection. The prevalence of N. gonorrhoeae infection was 0.6%. Only a reported history of or positive test for C. trachomatis was associated with gonorrheal infection. Of those testing positive for chlamydia, 14% reported symptoms versus 40% of those with gonorrhea. Younger age was not a predictor of either infection, as has been shown for women. A substantial number of male army recruits are infected with C. trachomatis, but few are infected with N. gonorrhoeae. Screening on the basis of symptoms alone would miss the majority of both infections.

Evaluation of use of a single intravaginal swab to detect multiple sexually transmitted infections in active-duty military women

The accuracy and suitability of use of a single intravaginal swab (SIS) for polymerase chain reaction detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and human papillomavirus infection was assessed in a cross-sectional study of 841 active-duty military women. The SIS, compared with standard diagnostic tests, allowed detection of more gonorrhea, more chlamydial infection, and more trichomoniasis. Sensitivity and specificity of SIS detection compared with adjudicated true-positive diagnoses were 95.8% and 97.8%, respectively, for gonorrhea, 94.6% and 99.3% for chlamydial infection, and 92.2% and 98.2% for trichomonal infection. Results with SISs were comparable to those with cervical swabs tested for human papillomavirus. Assay of clinician-collected and self-collected SISs yielded prevalences similar to those of standard diagnostic tests for all sexually transmitted infections. Therefore, the use of SISs is acceptable for the simultaneous diagnosis of multiple sexually transmitted infections and has potential for use as a self-administered diagnostic tool with widespread applicability among women.

Enhancing the specificity of the COBAS AMPLICOR CT/NG test for Neisseria gonorrhoeae by retesting specimens with equivocal results

The COBAS AMPLICOR CT/NG test for Neisseria gonorrhoeae cross-reacts with certain strains of nonpathogenic Neisseria species. In some strains, the target sequence is identical to that of N. gonorrhoeae, whereas other strains have a small number of mismatches within the regions recognized by the primers or probe used in the COBAS AMPLICOR NG test. These cross-reactive strains are occasionally present in urogenital specimens, causing false-positive results in the COBAS AMPLICOR NG test. Analysis of the data generated in a large multicenter clinical trial showed that 2.9% of the specimens gave signals between A(660)s of 0.2 and 3.5 but that one-half of these equivocal specimens did not contain N. gonorrhoeae. Most of these equivocal specimens were correctly classified as true positive or true negative by retesting in duplicate and defining a PCR-positive result as two of three results with an A(660) of > or =2.0. If specimens had been classified as positive or negative based on a single test result using a cutoff of an A(660) of 0.2, specificity would have ranged from 96.2 to 98.9% depending on specimen type, sex, and presence of symptoms. By employing the equivocal zone-retesting algorithm, specificity increased to 98.6 to 99.9% with little effect (0.1 to 4.9% decrease) on sensitivity in most specimen types, enabling the test to achieve a positive predictive value of at least 90% in populations with a prevalence of 4% or higher. In lower-prevalence populations, the test could be used to screen for presumptive infections that would have to be confirmed by an independent test.

Diagnosis of human papillomavirus infection by dry vaginal swabs in military women

OBJECTIVE

Human papillomavirus (HPV) assays are likely to be used with increasing frequency in clinical management of women with abnormal Papanicolaou smears and in cervical cancer screening. Our objective was to simplify the method of collection of female genital tract specimens. The utility of vaginal dry swabs for HPV diagnosis was evaluated.

METHODS

Specimens for cytology and for HPV identification were collected by a clinician from 189 female soldiers attending a military clinic. Three methods of specimen collection for HPV identification were compared: a vaginal dry swab (v-DRY), and vaginal and cervical swabs placed into specimen transport medium (v-STM and c-STM). Swabs were shipped to a STD laboratory for processing. Specific HPV types were identified by a consensus primer based PCR based method. Results from 165 women were evaluable.

RESULTS

HPV prevalence by the three methods was similar and ranged from 44.8% to 50.9%. 53 (32.1%) women were HPV positive and 60 (36.4%) women were HPV negative by all three collection methods. With respect to the risk categories of specific HPV types, there was greater agreement between the results from the two vaginal (v-DRY and v-STM) samples (kappa values of 0.69-0.81) than between the cervical (c-STM) and either of the vaginal samples (kappa values of 0.37-0.55). The HPV yield from c-STM was somewhat greater than that from the vaginal specimens but the correlation between cytological abnormalities and HPV was high for all three methods.

CONCLUSION

A dry vaginal swab may be an acceptable method of specimen collection for HPV diagnosis.

Chlamydia, gonorrhea, and HIV-1 prevalence among five populations of women in the Czech and Slovak Republics

BACKGROUND

Five populations at risk for sexually transmitted diseases (STDs) in the Czech and Slovak Republics were sampled.

GOAL

To estimate prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, and HIV-1 infections.

STUDY DESIGN

Urine specimens were collected serially from women at a Prague prenatal clinic (n = 134), a Prague dermatovenerealogy clinic (n = 91), sex workers from northern and central Bohemia (n = 35), students from a northern Bohemian school (n = 217), and Gypsies from Jarovnice, Slovakia (n = 128). These specimens were tested for chlamydia and gonorrhea using a ligase chain reaction pooling algorithm, and for HIV using an enzyme immunoassay confirmed by Western blot.

RESULTS

The prevalence of chlamydia was 2.2% (95% CI, 0.4-6.4) in the prenatal clinic, 5.5% (95% CI, 1.8-12.4) in the STD clinic, 22.9% (95% CI, 10.4-40.1) among street sex workers, 8.2% (95% CI, 3.6-15.6) among sexually active female high school students, and 3.9% (95% CI, 1.3-8.9) among Gypsy women. Gonorrhea was found in only two populations: 2.2% (95% CI, 0.3-7.7) in the STD clinic, and 2.9% (95% CI, 0.1-14.9) among sex workers. No HIV-1 infection was detected.

CONCLUSIONS

Urine screening was an efficient and accurate method for identifying groups at risk for STDs in the Czech Republic and Slovakia because sample collection was fast and noninvasive, and potential participation bias was reduced by high acceptability.

Multicenter evaluation of the BDProbeTec ET System for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine specimens, female endocervical swabs, and male urethral swabs

The performance of the Becton Dickinson BDProbe Tec ET System Chlamydia trachomatis and Neisseria gonorrhoeae Amplified DNA Assays (BD Biosciences, Sparks, Md.) was evaluated in a multicenter study. Specimens were collected from 2,109 men and women, with or without symptoms, attending sexually transmitted disease, family planning, and obstetrics and gynecology clinics. Both swab and urine samples were collected, and the results obtained from 4,131 specimens were compared to those from culture and the LCx nucleic acid amplification test (Abbott Industries, Abbott Park, Ill.). PCR and cytospin of the culture transport medium with chlamydia direct fluorescent antibody staining were used to adjudicate chlamydia culture-negative results. Sensitivity and specificity were calculated both with and without use of the amplification control (AC), with little apparent difference in the results. Without the AC result, sensitivity for C. trachomatis and N. gonorrhoeae were 92.8 and 96.6%, respectively, for cervical swabs and 80.5 and 84.9% for urine from women. C. trachomatis and N. gonorrhoeae sensitivities were 92.5 and 98.5%, respectively, for male urethral swabs and 93.1 and 97.9% for urine from men. This amplified DNA system for simultaneous detection of chlamydial and gonococcal infections demonstrated superior sensitivity compared to chlamydia culture and has performance characteristics comparable to those of other commercially available nucleic acid-based assays for these organisms.

Multicenter comparison trial of DNA extraction methods and PCR assays for detection of Chlamydia pneumoniae in endarterectomy specimens

The reported rate of detection of Chlamydia pneumoniae DNA within atherosclerotic lesions by PCR varies between 0 and 100%. In this study, identical sets of coded experimental atheroma samples (n = 15) and spiked controls (n = 5) were analyzed by 16 test methods in nine centers by means of PCR. The positive controls were correctly identified to levels of 1, 0.1, and 0.01 inclusion bodies of C. pneumoniae/ml of tissue homogenate by 16 (100%), 11 (69%), and 3 (19%) of the test methods, respectively. Three out of 16 negative controls (19%) were rated positive. Positivity rates for atheroma samples varied between 0 and 60% for the different test methods, with the maximum concordant result for positivity being only 25% for one carotid artery sample. There was no consistent pattern of positive results among the various laboratories, and there was no correlation between the detection rates and the sensitivity of the assay used.

Predictors of repeat Chlamydia trachomatis infections diagnosed by DNA amplification testing among inner city females

OBJECTIVE

To describe the epidemiology of prevalent and incident chlamydia infection in order to assess the appropriate interval for chlamydia screening; and to identify risk factors predictive of infection and repeat infections.

DESIGN

Prospective longitudinal study of a consecutive sample of 3860 sexually active females aged 12-60 years tested for C. trachomatis by polymerase chain reaction in Baltimore City clinics during 11,904 patient visits over a 33 month period.

RESULTS

Chlamydia prevalence, incidence, and frequency to diagnosis of infection varied by age. Among 2073 females < 25 years, chlamydia infection was found in 31.2%. The median times to first and repeat incident infections were 7.0 months and 7.6 months, respectively. Among 1787 females > or = 25 years, chlamydia infection was found in 9.6%. Median times to first and repeat incident infections were 13.8 months and 11.0 months, respectively. Age < 25 years yielded the highest risk of infection.

CONCLUSIONS

Since a high burden of chlamydia was found among mostly asymptomatic females < 25 years in a spectrum of clinical settings, we recommend chlamydia screening for all sexually active females < 25 years at least twice yearly.

Atherosclerosis in apoE knockout mice infected with multiple pathogens

Cytomegalovirus (CMV) and Chlamydia pneumoniae (CP) possibly contribute to atherosclerosis. Murine CMV (MCMV) and CP increase lesion size in apoE knockout mice. In this study, apoE knockout mice were infected with MCMV and CP to determine whether infection with multiple pathogens increases lesion size to a greater extent than either pathogen alone and whether infection with MCMV changes serum cytokine levels in a manner that could increase lesion development. One group of mice received MCMV at 2 weeks of age, followed by 2 doses of CP at 6 and 8 weeks of age. Additional groups received only MCMV or CP. Animals were killed at 16 weeks of age to determine lesion area. Infection with MCMV alone, CP alone, and both MCMV and CP increased lesion size 84% (P<.001), 70% (P<.0001), and 45% (P<.01), respectively. The MCMV-induced increase in circulating levels of interferon-gamma may have contributed to this increase.

Effect of azithromycin on murine arteriosclerosis exacerbated by Chlamydia pneumoniae

Chlamydia pneumoniae infection can exacerbate atherosclerosis in animals. To test the hypothesis that antibiotic therapy inhibits the atherogenic effects of C. pneumoniae infection, 10-week-old apolipoprotein E (ApoE) null mice were infected with C. pneumoniae or placebo, were treated for 2 weeks after infection with azithromycin or placebo, and were killed at 20 weeks of age. Infection did not affect the size of the aortic lesion, and antibiotic treatment had no effect. Another group of mice, 12-week-old ApoE mice, were infected with C. pneumoniae or placebo, were treated for 2 weeks after infection with azithromycin or placebo, and were killed at 26 weeks of age. C. pneumoniae infection increased the size of the lesion in infected mice, but azithromycin did not reduce the size of the aortic lesion in infected mice. Therefore, immediate therapy of acute infection may be necessary to prevent the proatherogenic effects of C. pneumoniae infection.

Point-of-entry screening for C. trachomatis In female army recruits. Who derives the cost savings?

BACKGROUND

Screening women for genital Chlamydia trachomatis at entry to military service provides an opportunity to reduce costs associated with sequelae of this infection. However, financial responsibility for screening may be debated. More than 50% of recruits return to civilian life within 2 years. The military and the civilian health care systems would both benefit from a screening program.

OBJECTIVE

To assess the cost-effectiveness and relative cost savings to the military and civilian health sectors of three screening strategies for U.S. Army female recruits for C. trachomatis using urine ligase chain reaction: screening all recruits, screening recruits aged < or = 25 years, and no screening.

METHODS

We applied a decision analytic model. Cost factors included screening, lost military training, morbid pelvic inflammatory disease, and other sequelae. Using a 5-year analytic horizon, we conducted analyses from military and civilian perspectives.

RESULTS

Screening 10,000 female army recruits would cost 193,500 dollars and prevent 282 cases of sequelae, with a projected savings of 53,325 dollars to the military and 505,053 dollars to the civilian sector. From a military perspective, screening women aged < or = 25 years provided the highest cost savings. Screening all female recruits incurred an incremental cost of $1199 per sequela prevented. From a civilian perspective, screening all recruits offered the greatest cost savings.

CONCLUSIONS

Screening female Army recruits for C. trachomatis offers substantial savings in health care costs for both the military and civilian health care systems. Relative financial benefit derived from recruit screening is disproportionate; greatest cost savings are enjoyed by the civilian sector.

Multicenter evaluation of AMPLICOR and automated COBAS AMPLICOR CT/NG tests for Neisseria gonorrhoeae

The fully automated COBAS AMPLICOR CT/NG and semiautomated AMPLICOR CT/NG tests were evaluated in a multicenter trial for their ability to detect Neisseria gonorrhoeae infections. Test performance compared to that of culturing was evaluated for 2,192 matched endocervical swab and urine specimens obtained from women and for 1, 981 matched urethral swab and urine specimens obtained from men. Culture-negative, PCR-positive specimens that tested positive in a confirmatory PCR test for an alternative target sequence within the N. gonorrhoeae 16S rRNA gene were considered to be true positives. The overall prevalences of gonorrhea were 6.6% in women and 20.1% in men. The COBAS AMPLICOR and AMPLICOR formats yielded concordant results for 98.8% of the specimens and exhibited virtually identical sensitivities and specificities. The results that follow are for the COBAS AMPLICOR format. With the infected patient as the reference standard, the resolved sensitivities of PCR were 92.4% for endocervical swab specimens and 64.8% for female urine specimens. There were no significant differences in these rates between women with and without symptoms. Among symptomatic men, COBAS AMPLICOR sensitivities were 94.1% for urine and 98.1% for urethral swabs; for asymptomatic men, the results were 42.3 and 73.1%, respectively. In comparison, the sensitivities of culturing were 84.8% for endocervical specimens, 92.7% for symptomatic male urethral specimens, and only 46.2% for urethral specimens obtained from asymptomatic men. When PCR results were analyzed as if only a single test had been performed on a single specimen type, the resolved sensitivity was always higher. The resolved specificities of PCR were 99.5% for endocervical swab specimens, 99.8% for female urine specimens, 98.9% for male urethral swab specimens, and 99.9% for male urine specimens. The internal control revealed that 2.1% of specimens were inhibitory when initially tested. Nevertheless, valid results were obtained for 99.2% of specimens because 60.0% of the inhibitory specimens were not inhibitory when a second aliquot was tested. The COBAS AMPLICOR CT/NG test for N. gonorrhoeae exhibited high sensitivity and specificity with urethral swab and urine specimens from men and endocervical swab specimens from women and thus is well suited for diagnosing and screening for N. gonorrhoeae infection.

Chlamydia pneumoniae serology: interlaboratory variation in microimmunofluorescence assay results

The lack of standardization in chlamydia serology has made interpretation of published data difficult. This study was initiated to determine the extent of interlaboratory variation of microimmunofluorescence (MIF) test results for the serodiagnosis of Chlamydia pneumoniae infections. Identical panels of 22 sera were sent to 14 laboratories in eight countries for the determination of IgG and IgM antibodies by MIF. Although there was extensive variation in the numeric titer values, the overall percentage agreement with the reference standard titers from the University of Washington was 80%. For results by serodiagnostic category, the best agreement was for four-fold rise in IgG titers, while the lowest agreement was for negative or low IgG titers. Agreement for IgM titers was 50%-95%. Four laboratories failed to discern false-positive IgM titers possibly because of the presence of rheumatoid factor. Further studies are underway to determine the source of interlaboratory variation for the MIF test.

Polymerase chain reaction detection of Chlamydia pneumoniae in circulating white blood cells

Several recently published studies suggest that Chlamydia pneumoniae may represent a risk factor for atherosclerosis or its complications. In order to establish whether C. pneumoniae is causally linked to atherosclerotic diseases, clinical intervention trials may be needed. However, to identify eligible subjects with a persistent C. pneumoniae infection and to monitor the effect of antibiotic therapy, there is a need for a reliable diagnostic marker. Blood-based polymerase chain reaction assays may be of value for identifying patients persistently infected with C. pneumoniae and for assessing the microbiologic efficacy of antichlamydial therapy in clinical intervention trials.

Growth in vascular cells and cytokine production by Chlamydia pneumoniae

The proposed pathogenesis of Chlamydia pneumoniae in atherosclerosis is supported by the finding that C. pneumoniae can initiate and sustain growth in human vascular cells. In vitro growth of C. pneumoniae is found in macrophages, peripheral blood monocyte (PBMC)-derived macrophages, endothelial cells, and aortic artery smooth muscle cells. U-937 macrophages infected with C. pneumoniae are capable of transmitting the infection to human coronary artery endothelial cells (CAEC) with direct cellular contact. Production of cytokines by cells infected with C. pneumoniae indicates that the organism can stimulate the immune system. CAEC infected with C. pneumoniae produce more interleukin-8 than cells sham inoculated with negative control cells. When interferon-gamma is used to stimulate HEp-2 cells, U-937 cells, and PBMC (before infection with C. pneumoniae), inhibition of a productive growth cycle occurs in a dose-related response. Studies are needed to learn the relationship between productive infection and persistence, the ability of C. pneumoniae to affect the immune response, and the potential for C. pneumoniae to influence atheromatous lesions.

The cost-effectiveness of varicella screening and vaccination in U.S. Army recruits

Varicella outbreaks in the U.S. Army disrupt training, reduce readiness, and represent substantial costs. Vaccination of susceptible individuals may be cost-effective. We conducted a cost-effectiveness analysis comparing screening of all incoming recruits and vaccination of susceptible individuals at either initial entry training (IET) or medical entrance processing station (MEPS), universal vaccination at IET, and no intervention. Primary health outcomes included the number of varicella cases prevented during the 8-week initial training period. The varicella hospitalization rate was 21.6 per 10,000 per year. In 100,000 recruits, 36 cases of varicella are expected at a cost of $181,000 in the absence of an intervention. Screening at IET would prevent 4 cases but would cost an additional $3,255,000 more than no intervention. Screening at MEPS would prevent 3 cases and save $521,000 per case prevented during the IET but would cost $2,734,000 more than no intervention. Universal vaccination would prevent 2 cases but would cost $15,858,000 more than MEPS screening and $18,592,000 more than no intervention. These results are robust. Cost per case of varicella prevented ranged from $390,000 to $7.9 million. Scarce prevention resources could be more cost-effectively allocated to other prevention programs.

Touchdown enzyme time release-PCR for detection and identification of Chlamydia trachomatis, C. pneumoniae, and C. psittaci using the 16S and 16S-23S spacer rRNA genes

Three touchdown enzyme time release (TETR)-PCR assays were used to amplify different DNA sequences in the variable regions of the 16S and 16S-23S spacer rRNA genes specific for Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci as improved tests for sensitive diagnosis and rapid species differentiation. The TETR-PCR protocol used 60 cycles of amplification, which provided improved analytical sensitivity (0.004 to 0.063 inclusion-forming unit of Chlamydia species per PCR). The sensitivity of TETR-PCR with primer set CTR 70-CTR 71 was 96.7%, and the specificity was 99.6%, compared to those of the AMPLICOR PCR for the detection of C. trachomatis in vaginal swab samples. TETR-PCR for C. pneumoniae with primer set CPN 90-CPN 91 was 90% sensitive and 93.3% specific compared with a nested PCR with primer set CP1/2-CPC/D for clinical respiratory samples. TETR-PCR for C. psittaci with primer set CPS 100-CPS 101 showed substantial agreement with cell culturing (kappa, 0.78) for animal tissue samples. Primer sets were then combined into a single multiplex TETR-PCR test. The respective 315-, 195-, and 111-bp DNA target products were precisely amplified when DNA from each of the respective Chlamydia species or combinations of them was used. Multiplex chlamydia TETR-PCR correctly identified one strain of each of the 15 serovars of C. trachomatis, 22 isolates of C. pneumoniae, and 20 isolates of C. psittaci. The primer sets were specific for each species. No target products were amplified when DNA from C. pecorum or a variety of other microorganisms was tested for specificity. TETR-PCR with primers selected for specific sequences in the 16S and 16S-23S spacer rRNA genes is a valuable test that could be used either with individual primers or in a multiplex assay for the identification and differentiation of Chlamydia species from culture isolates or for the detection of chlamydiae in clinical samples.

Multicenter evaluation of the AMPLICOR and automated COBAS AMPLICOR CT/NG tests for detection of Chlamydia trachomatis

The fully automated COBAS AMPLICOR CT/NG and semiautomated AMPLICOR CT/NG tests were evaluated in a multicenter trial for the ability to detect Chlamydia trachomatis infections. Test performance compared to that of culture was evaluated for 2,236 matched endocervical swab and urine specimens obtained from women and for 1,940 matched urethral swab and urine specimens obtained from men. Culture-negative, PCR-positive specimens that tested positive in a direct fluorescent-antibody test or in a confirmatory PCR test for an alternative target sequence were resolved as true positives. The overall prevalences of chlamydia were 2.4% in women and 7.2% in men. The COBAS AMPLICOR and AMPLICOR formats yielded concordant results for 98.1% of the specimens. With the infected patient as the reference standard, the resolved sensitivities of COBAS AMPLICOR were 89.7% for endocervical swab specimens, 89.2% for female urine specimens, 88.6% for male urethral swab specimens, and 90.3% for male urine specimens. When results were analyzed as if only a single test had been performed on a single specimen type, the resolved sensitivity was always higher. The resolved specificities of PCR were 99.4% for endocervical swab specimens, 99.0% for female urine specimens, 98.7% for male urethral swab specimens, and 98.4% for male urine specimens. The internal control revealed that 2.4% of the specimens were inhibitory when initially tested. Nevertheless, valid results were obtained for 98.6% of the specimens because 59.1% of the inhibitory specimens were not inhibitory when a second aliquot was tested. The COBAS AMPLICOR and AMPLICOR CT/NG tests for C. trachomatis exhibited equally high sensitivity and specificity with both urogenital swab and urine specimens and thus are well suited for screening for C. trachomatis infection.

In vitro infection and pathogenesis of Chlamydia pneumoniae in endovascular cells

The strength of the epidemiologic and clinical associations of Chlamydia pneumoniae with atherosclerosis can be increased by the demonstration that C pneumoniae can initiate and sustain growth in human vascular cells as well as in animal models. To investigate the biological basis for the dissemination and proliferation of this organism in vascular cells, the in vitro growth of C pneumoniae was studied in 2 macrophage cell lines, peripheral blood monocyte (PBMC)-derived macrophages, human bronchoalveolar lavage (BAL) macrophages, several endothelial cell lines, and aortic artery smooth muscle cells. Five of 5 strains of C pneumoniae were capable of 3 passages in human U-937 macrophages and in murine RAW 246.7 macrophages. Titers were suppressed in both macrophage types with each passage as compared with growth in HEp-2 cells. Both human BAL macrophages and PBMC-derived macrophages were able to inhibit C pneumonia eafter 96 hours' growth. Eleven C pneumoniae strains were capable of replicating in normal human aortic artery-derived endothelial cells, umbilical vein-derived endothelial cells, and pulmonary artery endothelial cells. Infection in human aortic artery smooth muscle cells was also established for 13 strains of C pneumoniae. C pneumoniae was also capable of growing in endothelial cells derived from human cadaver coronary artery endothelial cells (CAEC). U-937 human macrophages that were infected with C pneumoniae were capable of transmitting the infection to CAEC when they were brought into contact with the endothelial cells by centrifugation, rocking overnight, and direct layering overnight, with and without using artificial laboratory tissue culture enhancements, such as centrifugation of the inoculum and cycloheximide in the growth media. The in vitro ability of C pneumoniae to maintain infections in macrophages, endothelial cells, and aortic smooth muscle cells may provide support for the hypothesis that C pneumoniae can infect such cells, which when followed by an immune response may contribute to atheroma formation in vivo. Stimulation of cytokine responses by infection with C pneumoniae has indicated that this organism is capable of interacting with the immune system. In vitro infection by C pneumoniae of U-937 macrophages stimulated the production of IL-1beta, IFN-gamma, and TNF-alpha in tissue culture. Human CAEC that are infected with C pneumoniae produce more IL-8 compared with those inoculated with killed C pneumoniae or negative control cells, indicating a chemokine response to infection that may play a role in recruitment of inflammatory cells to sites of infection in vascular cells. When IFN-gamma was used to up regulate HEp-2 and U-937 cells before infection by C pneumoniae, inhibition of a lytic growth cycle occurred in a dose related response. However, removal of the IFN-gamma after 24 to 48 hours' exposure allowed subsequent productive growth in the cells, perhaps indicating the prior induction of a persistent infection. More studies are needed to study the complex relationship between lytic infection and persistence, the ability of C pneumoniae to affect the immune response of vascular cells, and the potential for C pneumoniae to influence the initiation of or progression of atheromatous lesions.

Control of Chlamydia trachomatis infections in female army recruits: cost-effective screening and treatment in training cohorts to prevent pelvic inflammatory disease

CONTEXT

Chlamydia trachomatis genitourinary infections in females can lead to serious and costly sequelae. Programs such as basic (initial entry) military training with controlled points of entry offer an opportunity to screen large cohorts of women at risk for infection.

OBJECTIVE

To assess the cost-effectiveness of three interventions for C. trachomatis infections in women beginning Army training: 1) screening using urine ligase chain reaction (LCR) by age, 2) unrestricted testing using urine LCR, and 3) universal antibiotic treatment with azithromycin.

DESIGN

Cost-effectiveness analysis from a military perspective.

SETTING AND PATIENTS

A hypothetical cohort of 10,000 women who intended to complete at least 2 years of military service was studied. Analysis was based on data from 13,204 female trainees screened for chlamydial infection at Fort Jackson, SC.

OUTCOMES

Program and training costs, cost of illness averted, and pelvic inflammatory disease (PID) prevented were determined for a 1-year follow-up period. Using sensitivity analysis, outcomes over 2 years were studied.

RESULTS

At a 9.2% prevalence, no screening resulted in $220,900 in training and sequelae costs and 276 cases of PID. Screening by age produced the lowest cost $217,600, over a 1-year period and prevented 222 cases of PID for a cost-savings of $15 per case of PID prevented. Universal testing prevented an additional 11 cases of PID at a cost of $226,400, or costing $800 per additional case of PID prevented over age-targeted screening. Universal treatment prevented an additional 32 cases of PID and cost $221,100, saving $167 per additional cases of PID prevented over universal screening. Over a 2-year period, universal treatment provided the highest cost-savings and prevented the most disease.

CONCLUSION

Screening by age provided a cost-savings to the Army over a 1-year period. Other organizations accessing large cohorts of young women could also benefit, even in the short term, from implementation of an age-based chlamydial screening program. Universal testing or universal treatment may be warranted in which long-term societal goals, such as maximum reduction of PID, are relevant.

Control of sexually transmitted diseases for AIDS prevention in Uganda: a randomised community trial. Rakai Project Study Group

BACKGROUND

The study tested the hypothesis that community-level control of sexually transmitted disease (STD) would result in lower incidence of HIV-1 infection in comparison with control communities.

METHODS

This randomised, controlled, single-masked, community-based trial of intensive STD control, via home-based mass antibiotic treatment, took place in Rakai District, Uganda. Ten community clusters were randomly assigned to intervention or control groups. All consenting residents aged 15-59 years were enrolled; visited in the home every 10 months; interviewed; asked to provide biological samples for assessment of HIV-1 infection and STDs; and were provided with mass treatment (azithromycin, ciprofloxacin, metronidazole in the intervention group, vitamins/anthelmintic drug in the control). Intention-to-treat analyses used multivariate, paired, cluster-adjusted rate ratios.

FINDINGS

The baseline prevalence of HIV-1 infection was 15.9%. 6602 HIV-1-negative individuals were enrolled in the intervention group and 6124 in the control group. 75.0% of intervention-group and 72.6% of control-group participants provided at least one follow-up sample for HIV-1 testing. At enrolment, the two treatment groups were similar in STD prevalence rates. At 20-month follow-up, the prevalences of syphilis (352/6238 [5.6%]) vs 359/5284 [6.8%]; rate ratio 0.80 [95% CI 0.71-0.89]) and trichomoniasis (182/1968 [9.3%] vs 261/1815 [14.4%]; rate ratio 0.59 [0.38-0.91]) were significantly lower in the intervention group than in the control group. The incidence of HIV-1 infection was 1.5 per 100 person-years in both groups (rate ratio 0.97 [0.81-1.16]). In pregnant women, the follow-up prevalences of trichomoniasis, bacterial vaginosis, gonorrhoea, and chlamydia infection were significantly lower in the intervention group than in the control group. No effect of the intervention on incidence of HIV-1 infection was observed in pregnant women or in stratified analyses.

INTERPRETATION

We observed no effect of the STD intervention on the incidence of HIV-1 infection. In the Rakai population, a substantial proportion of HIV-1 acquisition appears to occur independently of treatable STD cofactors.

Pooling of urine samples for screening for Neisseria gonorrhoeae by ligase chain reaction: accuracy and application

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.