Asymptomatic sexually transmitted disease prevalence in four military populations: application of DNA amplification assays for Chlamydia and gonorrhea screening

The Association between Sexually Transmitted Infections, Length of Service and Other Demographic Factors in the U.S. Military

BACKGROUND

Numerous studies have found higher rates of sexually transmitted infections (STIs) among military personnel than the general population, but the cumulative risk of acquiring STIs throughout an individual's military career has not been described.

METHODS

Using ICD-9 diagnosis codes, we analyzed the medical records of 100,005 individuals from all service branches, divided in equal cohorts (n = 6,667) between 1997 and 2011. As women receive frequent STI screening compared to men, these groups were analyzed separately. Incidence rates were calculated for pathogen-specific STIs along with syndromic diagnoses. Descriptive statistics were used to characterize the individuals within each accession year cohort; repeat infections were censored.

RESULTS

The total sample included 29,010 females and 70,995 males. The STI incidence rates (per 100 person-years) for women and men, respectively, were as follows: chlamydia (3.5 and 0.7), gonorrhea (1.1 and 0.4), HIV (0.04 and 0.07) and syphilis (0.14 and 0.15). During the study period, 22% of women and 3.3% of men received a pathogen-specific STI diagnosis; inclusion of syndromic diagnoses increased STI prevalence to 41% and 5.5%, respectively. In multivariate analyses, factors associated with etiologic and syndromic STIs among women included African American race, younger age and fewer years of education. In the overall sample, increasing number of years of service was associated with an increased likelihood of an STI diagnosis (p<0.001 for trend).

CONCLUSION

In this survey of military personnel, we found very high rates of STI acquisition throughout military service, especially among women, demonstrating that STI-related risk is significant and ongoing throughout military service. Lower STI incidence rates among men may represent under-diagnosis and demonstrate a need for enhancing male-directed screening and diagnostic interventions.

Lawrence JS. Urine Tests for Gonorrhea and Chlamydia: Great Technology but Will the Community Accept It?

Semi-structured interviews were conducted with 311 respondents in seven inner-city communities within the United States in an effort to examine factors that promote regular urine-based screening for chlamydia and gonorrhea. Results suggested that the majority of respondents were in favor of the use of urine-based testing for the detection of sexually transmitted infections (STIs), indicating that regular urine testing is important for diagnosis, early detection, prevention, and treatment of STIs. The most common concerns reported were stigma associated with STIs, the time required for testing, the possibility of receiving inaccurate laboratory results, and the higher cost of urine testing. The ease and accuracy of urine testing in addition to its high acceptance suggest that screening programs for STIs using urine-based testing could be implemented and used quite effectively to control the transmission of STIs.

High-risk behavior and sexually transmitted infections among U.S. active duty servicewomen and veterans

The number of women who are active duty service members or veterans of the U.S. military is increasing. Studies among young, unmarried, active duty servicewomen who are sexually active indicate a high prevalence of risky sexual behaviors, including inconsistent condom use, multiple sexual partners, and binge drinking, that lead to unintended and unsafe sex. These high-risk sexual practices likely contribute to chlamydia infection rates that are higher than the rates in the U.S. general population. Human papillomavirus (HPV) infection and cervical dysplasia may also be higher among young, active duty servicewomen. Little is known about the sexual practices and rates of sexually transmitted infections among older servicewomen and women veterans; however, women veterans with a history of sexual assault may be at high risk for HPV infection and cervical dysplasia. To address the reproductive health needs of military women, investigations into the prevalence of unsafe sexual behaviors and consequent infection among older servicewomen and women veterans are needed. Direct comparison of military and civilian women is needed to determine if servicewomen are a truly high-risk group. Additionally, subgroups of military women at greatest risk for these adverse reproductive health outcomes need to be identified.

Circumcision and the risk of prostate cancer

BACKGROUND

Several lines of evidence support a role for infectious agents in the development of prostate cancer (PCa). In particular, sexually transmitted infections (STIs) have been implicated in PCa etiology, and studies have found that the risk of acquiring a STI can be reduced with circumcision. Therefore, circumcision may reduce PCa risk.

METHODS

Participant data collected as part of 2 population-based case-control studies of PCa were analyzed. Self-reported circumcision status, age at circumcision, and age at first sexual intercourse were recorded along with a history of STIs or prostatitis. Multivariate logistic regression was used to estimate the relative risk of PCa by circumcision status.

RESULTS

Data from 1754 cases and 1645 controls were available. Circumcision before first sexual intercourse was associated with a 15% reduction in risk of PCa compared to that of uncircumcised men (95% confidence interval [CI], 0.73-0.99). This risk reduction was observed for cases with both less aggressive (odds ratio, 0.88; 95% CI, 0.74-1.04) and more aggressive (odds ratio, 0.82; 95% CI, 0.66-1.00) PCa features.

CONCLUSIONS

Circumcision before first sexual intercourse is associated with a reduction in the relative risk of PCa in this study population. These findings are consistent with research supporting the infectious/inflammation pathway in prostate carcinogenesis.

Chlamydia trachomatis positivity rates among men tested in selected venues in the United States: a review of the recent literature

The cost-effectiveness of screening men for Chlamydia trachomatis depends in part on the prevalence of chlamydia in the screened population and the ease with which screening programs can be implemented. Screening in venues with high rates of chlamydia positivity among men may therefore be an important adjunct to chlamydia control. To evaluate the recent US literature on chlamydia positivity in chlamydia screening programs among asymptomatic men in nonsexually transmitted disease clinic settings, we reviewed published articles between 1995 and June 2007, using PubMed as the primary search tool. Articles were abstracted and positivity rates summarized by type of venue, race/ethnicity, age group, and US region. The overall median positivity rate was 5.1%. The highest rates were observed among men tested in juvenile (7.9%) and adult (6.8%) detention facilities, among blacks (6.7%), the 15 to 19 years old (6.1%) and 20 to 24 years old (6.5%) age groups, and among men screened in the southern United States (6.4%). Chlamydia rates among men are high in certain venues, particularly correctional settings, but also depend on the demographic composition of the target population and location. Programs considering male chlamydia screening programs should conduct pilot programs to assess chlamydia positivity as well as feasibility and cost in target venues.

Incidence rates of pelvic inflammatory disease diagnoses among Army and Navy recruits potential impacts of Chlamydia screening policies

BACKGROUND

U.S. Navy policy requires Chlamydia trachomatis screening of all women upon entry to recruit training in conjunction with an educational session, and yearly screening thereafter until age 25. Army policy directs only annual screening of asymptomatic women aged <25. Hence, screening of Army recruits may not occur for up to 12 months following accession. Using routinely collected surveillance data, the rates of outpatient pelvic inflammatory disease (PID) following accession into the Army or Navy were compared to assess the potential implications of these policies.

METHODS

The population at risk comprised active-component women aged <25 who accessioned to either the U.S. Army or Navy between January 1, 2001, and December 31, 2005. Subjects were followed up to 60 months from accession, either until a first outpatient PID diagnosis occurred or they departed from military service. Data were collected from 2001 to 2006 and analyzed in 2007. Multiple Poisson regression was used to assess the effects of potentially important covariates. Time-to-event analysis was employed to characterize risk over time.

RESULTS

There were 1276 and 546 incident outpatient diagnoses of PID among 58,088 Army and 33,046 Navy accessions during 93,918 and 65,863 person-years of follow-up, respectively. The crude incident rate was 64% higher in the Army (13.6/1000 person-years) than the Navy (8.3/1000 person-years). Risk for the Army increased soon after accession, followed by a decline, while risk for the Navy remained comparatively uniform.

CONCLUSIONS

PID rates were higher in the Army than Navy during the first years of active service. A comprehensive study to elucidate the source of this observed difference is warranted.

Biomedical Research on Health and Performance of Military Women: Accomplishments of the Defense Women's Health Research Program (DWHRP)

In 1994, Congress provided dollar 40 M for biomedical research on issues of importance for military women. This supported 104 intramural and 30 extramural studies and launched an era of research to narrow the knowledge gap on protection and enhancement of health and performance of military women. Projects addressed issues specific to female physiology (e.g., gynecological health in the field, maternal malaria), problems with higher prevalence for women (e.g., marginal iron deficiency, stress fracture), and issues of drug and materiel safety that had only been extrapolated from studies of men (e.g., chemical agent prophylaxis, fatigue countermeasures). Several important assumptions about female physiology and occupational risks were found to be astoundingly wrong. Hormonal changes through the menstrual cycle were less important to acute health risks and performance than predicted, exercise did not increase risk for amenorrhea and consequent bone mineral loss, and women tolerated G-forces and could be as safe as men in the cockpit if their equipment was designed for normal size and strength ranges. Data on personal readiness issues, such as body fat, physical fitness, nutrition, and postpartum return to duty, allowed reconsideration of standards that were gender appropriate and not simply disconnected adjustments to existing male standards. Other discoveries directly benefited men as well as women, including development of medical surveillance databases, identification of task strength demands jeopardizing safety and performance, and greater understanding of the effects of psychosocial stress on health and performance. This surge of research has translated into advances for the welfare of service women and the readiness of the entire force; relevant gender issues are now routine considerations for researchers and equipment developers, and some key remaining research gaps of special importance to military women continue to be investigated.

Screening sexually active adolescents for Chlamydia trachomatis: what about the boys?

OBJECTIVES

We sought to determine the effectiveness of a systems-based intervention designed to increase Chlamydia trachomatis (CT) screening among adolescent boys.

METHODS

An intervention aimed at increasing CT screening among adolescent girls was extended to adolescent boys (14-18 years). Ten pediatric clinics in a health maintenance organization with an ethnically diverse population were randomized. Experimental clinics participated in a clinical practice improvement intervention; control clinics received traditional information on screening.

RESULTS

The intervention significantly increased CT screening at the experimental sites from 0% (baseline) to 60% (18-month posttest); control sites evidenced a change only from 0% to 5%. The overall prevalence of CT was 4%.

CONCLUSIONS

Although routine CT screening is currently recommended only for young sexually active women, the present results show that screening interventions can be successful in the case of adolescent boys, among whom CT is a moderate problem.

Nucleic acid amplification tests for gonorrhea and chlamydia: practice and applications

Nucleic acid amplification tests (NAATs), which are highly sensitive and specific, have provided the ability to use alternative sam-ple types for the diagnosis of sexually transmitted infections (STIs). Self-collected genital specimens, such as urine or even vaginal swabs, can now be accurately used to diagnose gonorrhea or chlamydia infections. In many cases, use of these sample types can decrease the necessity for a clinician to perform a pelvic examination on women or to collect a urethral swab from men, thus extending the diagnostic capability for detecting these infections to nonclinic screening venues. As most chlamydia infections and many gonorrhea infections are asymptomatic, the use of NAATs for self-collected samples greatly increases the types and numbers of patients that can be screened outside of clinic settings. Self-sampling also allows clinicians to easily screen patients in the clinic for STIs who are not presenting for pelvic or urogenital examinations. The application of NAATs to self-collected specimens has the potential to augment public health programs designed to control the epidemic of STIs in the community.

Evaluation of a cognitive-behavioral, group, randomized controlled intervention trial to prevent sexually transmitted infections and unintended pregnancies in young women

BACKGROUND

Few cognitive-behavioral interventions have focused on preventing sexually transmitted infections (STIs) and unintended pregnancies (UPs) in young, sexually active women in a single study. Military recruit training provides a well-defined, national, nonclinic sample in which to evaluate such an intervention.

METHODS

All female Marine recruits (N=2,288) in training were approached. Of these, 2,157 (94.3%) voluntarily agreed and were randomly assigned, by platoons, to participate in cognitive-behavioral interventions to prevent STIs or UPs or to prevent physical training injuries and cancer. Participants completed self-administered questionnaires and were screened for pregnancy, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis at baseline and, on average, 1 and 14 months postintervention.

RESULTS

A higher proportion of the control group had a postintervention STI or UP [odds ratio (OR)=1.41, 95% confidence interval (CI)=1.01-1.98]. Among participants who had no history of STIs or pregnancy, but who engaged in risky sexual behaviors just before recruit training, the control group was more likely to acquire a postintervention STI (OR=3.24, CI=1.74-6.03). Among participants who were not sexually experienced at baseline, the control group was more likely to have casual (OR=2.05, 95% CI=1.04-4.08) and multiple (OR=1.87, 95% CI=1.01-3.47) sexual partners postintervention.

CONCLUSIONS

This randomized controlled trial indicates that cognitive-behavioral interventions are effective for reducing behavioral risk and preventing STIs and UPs in young, sexually active women who are not seeking health care.

Multicomponent Internet continuing medical education to promote chlamydia screening

BACKGROUND

Low Chlamydia trachomatis screening rates create an opportunity to test innovative continuing medical education (CME) programs. Few studies of Internet-based physician learning have been evaluated with objective data on practice patterns.

DESIGN

This randomized controlled trial tested a multicomponent Internet CME (mCME) intervention for increasing chlamydia screening of at-risk women aged 16 to 26 years.

SETTING

Eligible physician offices had > or =20 patients at risk for chlamydia as defined by the Health Plan Employer Data and Information Set (HEDIS), had at least one primary care physician (internal medicine, family medicine/general practice, pediatrics) with Internet access, and participated in the study managed care organization. The 191 randomized primary care offices represented 20 states.

INTERVENTION

The intervention, available from February to December 2001, consisted of four case-based learning modules, was tailored in real time to each physician based on theory of behavior change, and included office-level feedback of chlamydia screening rates.

MAIN OUTCOME MEASURE

HEDIS chlamydia screening rates for the pre-intervention (2000) and post-intervention (2002) periods.

RESULTS

Pre-intervention screening rates for the intervention and comparison offices were 18.9% and 16.2% (p =0.135). Post-intervention screening rates for the intervention and comparison offices were 15.5% and 12.4%, respectively (p =0.044, adjusting for baseline performance).

CONCLUSIONS

The substantial decline in chlamydia screening rates observed in the comparison offices was significantly attenuated for the intervention offices. The mCME favorably influenced chlamydia screening by primary care physicians.

Prevalence of Chlamydia trachomatis in Asymptomatic Brazilian Military Conscripts

BACKGROUND

Few data are available on the prevalence and risk factors for Chlamydia trachomatis infection among young men in Brazil.

OBJECTIVES

To assess prevalence and risk factors for C. trachomatis infection in male military conscripts.

METHODS

In 2000, 627 young men recruited for military service in Goiania, Goias, Brazil, were enrolled in this cross-sectional study. Participants completed a demographic and sexual risk behavior questionnaire, and urine samples were screened for C. trachomatis by polymerase chain reaction.

RESULTS

The prevalence of chlamydial infection among asymptomatic conscripts was 5.0% (95% confidence interval [CI], 3.3-7.3). In multivariate analysis, failure to use condoms (odds ratio [OR](adjusted) 5.3; 95% confidence interval [CI], 1.2-23.4; P = 0.028) and having more than 2 sexual partners in the last 2 months (OR(adjusted) 2.6; 95% CI, 1.1-6.9; P = 0.049) were significantly associated with positivity for C. trachomatis.

CONCLUSIONS

A substantial number of asymptomatic young male military recruits were infected with C. trachomatis, and risk factors for this infection were related to sexual behavior. Further research is required to determine if routine screening may be considered as a strategy to reduce prevalence among this population.

Urine nucleic acid amplification tests for the diagnosis of sexually transmitted infections in clinical practice

PURPOSE OF REVIEW

With the advent of highly sensitive and specific nucleic acid amplification assays, this report will demonstrate that self-collected genital specimens, such as urine or even vaginal swabs can be accurately used to diagnose sexually transmitted infections.

RECENT FINDINGS

Use of self collected samples can eliminate the necessity of a clinician to perform a pelvic examination for women or collect a urethral swab for men, thus extending the diagnostic capability for sexually transmitted infections to non-clinic screening venues. As many sexually transmitted infections are asymptomatic, this ability to use self-sampling greatly increases the numbers of patients that can be screened, and has the potential to augment public health programs designed to control the epidemic of sexually transmitted infections in the community. Patient collected samples are highly acceptable, highly accurate, and are becoming widely used. Self-sampling also allows clinicians to easily screen patients in the clinic, who are not presenting for pelvic or urogenital examinations, for sexually transmitted infections.

SUMMARY

Highly accurate molecular tests and easily obtained self-collected urogenital samples represent the ideal combination for obtaining the public health goal of decreasing the sexually transmitted infection epidemic among sexually active persons in the United States today.

Incidence of sexually transmitted infections in asymptomatic healthy young Japanese men

The aim of this study was to estimate the incidence rates of asymptomatic sexually transmitted infections (STI) in young men in Sapporo, Japan. A survey of 204 healthy male volunteers was conducted. First-voided urine specimens were used for detection of Chlamydia trachomatis and Neisseria gonorrhoeae with polymerase chain reaction assay, and cotton swab wiping of the external genitalia was used for detection of human papillomavirus (HPV) with the Hybrid Capture method. The incidence rates were 3.4% for C. trachomatis and 5.9% for HPV. No N. gonorrhoeae was detected. In sexually active men who had regular sexual intercourse, the detection rate of C. trachomatis was 4.7% and that of HPV was 8.0%. Our study showed that the incidence rates of asymptomatic STIs were not negligible, and that we should provide screening programs for young men with a high risk for such unrecognized infections and study their natural histories.

Developments in the screening for Chlamydia trachomatis: a review

Many studies have evaluated selective screening criteria for women in various settings. Most have concluded and all guidelines recommend that all women aged < 25 be screened yearly for C. trachomatis infection. Behavioral criteria, such as the number of sex partners, new or more than one sex partners, and previous infection, also can serve as criteria for screening women aged > 25. Because re-infection rates are high and occur within a few months, complications may be reduced further if partners are treated and women rescreened 4 to 6 months after initial infection. Revised recommendations for C. trachomatis screening programs have stated that more frequent screening may be considered among women < 20 and those with recent infection. Screening in nontraditional settings and careful evaluation of local prevalence and risk factor information should be encouraged. Private providers and emergency room providers should discuss screening recommendations and adopt a C. trachomatis screening policy for the population they serve. The HEDIS measure should serve to encourage at least annual screening of 15- to 25-year-old sexually active females through providers linked to managed care organizations. In general, high yields (ie, percentage of tests that are positive) in nontraditional settings and enhanced feasibility and acceptability of urine-based tests may encourage further innovative approaches to reach and screen populations at risk. Several issues remain to be addressed to increase the effectiveness of screening efforts. If more sensitive amplification tests are used widely, more infected persons will be identified and treated, and transmission patterns may change, particularly if partner treatment also occurs. Current screening criteria should continue to be re-evaluated. An important issue that affects testing methods includes the possible need for confirmation testing when using NAATs if the prevalence of C. trachomatis is less than 2%. If the sensitivity of an NAAT is 85% and specificity is 99%, in a hypothetical population of 10,000 with a prevalence of 2%, the positive predictive value is 170/268 (63%). A second important issue affecting testing methods and feasibility of using NAATs for screening large numbers of individuals is the pooling of urine specimens, which has been evaluated in several studies and found to be very effective for reducing costs. A research issue for pooling is the determination of the most cost-effective prevalence levels for pooling. An additional research question is in which populations should a NAAT be used for detection of C. trachomatis and N. gonorrhoeae. There are no recommendations for the routine screening of men because of the paucity of data showing that this strategy can reduce sequelae. The CDC is conducting a multisite study to examine the feasibility, acceptability, and usefulness of screening of asymptomatic men. There are a few studies have determining cost-effective prevalence threshold levels, particularly with NAATs. A recently developed decision analysis model by CDC designed to maximize the effectiveness of screening strategies for C. trachomatis infections may be useful for decision makers. It is intended to serve as an easy and flexible tool to determine cost effectiveness at a local level and takes into account positivity rates and test performance characteristics (SOCRATES). It is unclear if recurrent infection is caused by true re-infection by the same or a different partner or recurrence of initial infection. Recurrence may be caused by persistence of C. trachomatis or antibiotic resistance. This distinction is of scientific interest because the appropriate intervention differs (eg, identification of risk factors for the former and microbiologic investigations for the latter). Effective partner management and retesting are critical to reducing sequelae of C. trachomatis infection. Screening for C. trachomatis infection remains an essential component of C. trachomatis control. It is cost effective, most infections are asymptomatic, and symptom-based health care seeking and testing identify few of those infected. The likelihood that opportunities for screening are missed is high particularly in non-STD clinic settings. Local studies using NAATs to determine C. trachomatis prevalence and risk factors are helpful to health care providers so they can make evidence-based decisions on who to screen. The use of nontraditional, non-clinic-based test settings should be explored further. We have focused on summarizing the medical evidence regarding recommendations for screening for C. trachomatis. High-risk populations for C. trachomatis infection may overlap with populations for other STDs, and comprehensive STD prevention programs that involve a range of STD service providers are needed to successfully reduce the STD-related health burden in the population.

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.

Generalizability of STD screening in urban emergency departments: comparison of results from inner city and urban sites in Baltimore, Maryland

BACKGROUND

A previous study in an inner city emergency department (ED) in Baltimore, Maryland, showed a high prevalence of gonorrhea and chlamydia infection among ED patients.

GOAL

The goal was to compare results from an inner city ED to results from an urban ED in Baltimore, in terms of study population and setting, risks for infection, and factors associated with nonparticipation in the study.

METHODS

This was a cross-sectional study of patients aged 14 to 44 years at two EDs. Outcomes for multivariate logistic regression analyses were (1). positive for gonorrhea or chlamydia by urine ligase chain reaction assay and (2). nonparticipation in the study. Comparative analyses were limited to patients aged 18 to 31 years.

RESULTS

Patients differed significantly between EDs by participation rate, distribution of race/ethnicity, healthcare access, and behavioral risks, although the prevalence of infection did not differ. Risks for infection at the inner city ED were younger age, history of STD, and recent number of sex partners. Risks for infection at the urban ED were female gender and recent number of sex partners. At both EDs, being African American was associated with increased chance of participating, whereas lack of any genitourinary complaint was associated with nonparticipation. At the urban ED, women and patients approached for study enrollment during the day were also less likely to participate.

CONCLUSION

ED-based screening for STDs can be an effective intervention for unrecognized infections. However, assessing population characteristics is necessary to develop targeted screening methods and clinical algorithms and to improve participation of patients and program sustainability.

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.

Prevalence, incidence, and correlates of chlamydia and gonorrhea among young adult injection drug users

PURPOSE

To measure prevalence, incidence, and correlates of chlamydia and gonorrhea among injection drug users (IDUs).

METHODS

Participants (n = 2129; 63% male, 52% white, ages 18-30 years) in five US cities were tested for chlamydia and gonorrhea by urine LCR assay and completed a standardized questionnaire about demographics and recent sexual behavior. Logistic regression identified correlates of prevalent infection; incidence rates were calculated from 6-month follow-up data.

RESULTS

Chlamydia prevalence was 5.2% and did not differ by gender. Gonorrhea prevalence was 0.2% among men and 2.0% among women, P < .001. Among men, younger age [OR (95% CI): 0.89 (0.83-0.96)], age at sexual debut [0.91 (0.83-0.99)], and African American race [2.92 (1.53-5.59)] were associated with chlamydia. Among women, age at sexual debut [1.16 (1.02-1.31)] and commercial sex [1.96 (1.03-3.74)] were associated with chlamydia, and with gonorrhea [1.27 (1.04-1.56)] and [5.17 (1.66-16.11)], respectively. At 6 months, the cumulative incidence of chlamydia was 1.7% among men and 4.4% among women, P = .03; no men and 1.3% of women tested positive for gonorrhea, P = .01.

IMPLICATIONS

Prevalence and correlates of chlamydia and gonorrhea were similar to other samples, suggesting that screening criteria need not be modified for IDU populations. The number of behavioral correlates identified was limited; perhaps unmeasured sexual-network-level factors play a role in determining sexually transmitted disease (STD) prevalence.

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.

Urinary screening for Neisseria gonorrhoeae in asymptomatic individuals from Queensland, Australia: an evaluation using three nucleic acid amplification methods

A comparison between three nucleic acid amplification methods (COBAS AMPLICOR NG, Abbott LCx NG and in-house cppB gene PCR) for the detection of Neisseria gonorrhoeae was undertaken using non-consecutive urine specimens collected from a high prevalence asymptomatic population (260 patients) from multiple sites in Queensland, Australia. Sensitivity, specificity, positive predictive value and negative predictive value were as follows: COBAS 97.9, 93.9, 78.0, 99.5%; LCx 95.7, 100, 100, 99.1%; cppB 97.9, 100, 100, 99.5%. The results provide further evidence that false-positive COBAS AMPLICOR NG PCR results are a significant problem in our population, and that the Abbott NG LCx is a suitable alternative for screening asymptomatic populations with a high prevalence of N. gonorrhoeae carriage.

Incidence of recurrent diagnoses of Chlamydia trachomatis genital infections among male and female soldiers of the US Army

BACKGROUND/OBJECTIVES

Few studies of Chlamydia trachomatis incidence, especially among men, and most studies of C. trachomatis in US military populations are cross sectional prevalence surveys. A population based retrospective cohort was used to determine risk factors for repeat diagnoses of genital C. trachomatis infections among male and female soldiers with previous C. trachomatis infections.

METHODS

All active duty soldiers diagnosed with C. trachomatis genital infections between 1994 and 1998. Cohort members were passively followed until repeat diagnoses of C. trachomatis infection, termination of army service, or the end of the study.

RESULTS

Among 11,771 soldiers with initial diagnoses of chlamydia, the crude rate of repeat diagnoses was 52.0 per 1000 person years. Women and men aged 20-24 were at greatest unadjusted risk of reinfection. After adjustment, women aged 20-24 and men aged 25-29 were at higher risk than their younger or older counterparts.

CONCLUSIONS

Results of this study suggest that both male and female soldiers who are diagnosed with chlamydia infections have relatively high risks of reinfection through their 20s.

Trends of gonorrhea and chlamydial infection during 1985-1996 among active-duty soldiers at a United States Army installation

High rates of sexually transmitted diseases (STDs) have been reported in military populations. However, it remains uncertain whether the incidence of STDs is higher among military personnel than in the civilian population. The annual incidence of gonorrhea and chlamydia from 1985 through 1996 at Fort Bragg, North Carolina, was determined by use of a clinic database and demographic information for the entire installation. A direct standardization for age, sex, and race/ethnicity was performed, and the adjusted annual rates among active duty soldiers were compared with rates among men and women in North Carolina and the United States. Results showed that the adjusted incidence of gonorrhea and chlamydia among Fort Bragg soldiers remained higher overall than comparable state and national rates during the period of analyses. The 1996 adjusted chlamydia rates for male and female active duty soldiers were 3-fold to 6-fold higher than rates for males and females in North Carolina and in the United States as a whole. STDs continue to lead to significant morbidity in this representative military population.

Sexually transmitted diseases in women. Gonorrhea and syphilis

Gonorrhea has been declining since its 1975 peak. Risk factors include age 15 to 19 years, multiple or casual sexual contacts, sexual activity related to drug use, and low socioeconomic status. Infection is usually mild but may be asymptomatic. While no physical signs are specific to the gonococcus, pelvic inflammatory disease is a common complication and cause of infertility and should be treated if it is suspected. Diagnosis of gonorrhea is typically by culture. Newer, more accurate tests are available but are more expensive. For treatment, the CDC recommends only highly effective regimens. Patients need to refer recent sexual partners for treatment and abstain from sexual intercourse until completion of therapy and resolution of symptoms. The incidence of syphilis appears to be declining in the United States, but it should be considered if an ulcer is found in the genital region. If untreated, the disease progresses through primary, secondary, latent, and tertiary phases, and systemic symptoms can mimic other conditions. Positive standard screening tests should be confirmed by fluorescent treponemal antibody absorption testing. Darkfield microscopy is appropriate for diagnosis of an ulcer. The treatment of choice for all phases of syphilis is a single dose of intramuscular benzathine penicillin. Other components of therapy include partner notification and patient follow-up. The spread of HIV is closely linked to STD transmission. Therefore, testing for HIV is strongly encouraged when another STD has been diagnosed.

Comparison of Abbott LCx Chlamydia trachomatis assay with Gen-Probe PACE2 and culture

In this study the LCx assay (a nucleic acid amplification assay) for Chlamydia trachomatis in endocervical samples was compared with the Gen-Probe PACE2 assay (a nucleic acid probe assay) for endocervical samples, and with endocervical culture. In addition, the efficacy of the LCx assay was determined for midstream clean-catch urine samples because it is often necessary to obtain such a sample for routine urine culture and it is simpler to collect only a single sample without also collecting a first-void urine for LCx. Endocervical specimens from 205 patients were tested for C. trachomatis via LCx and PACE2. Of these patients, 203 were tested by culture. Midstream clean-catch urine samples from 75 of these patients were tested by LCx. The sensitivities and specificities for these assays, after discrepant analysis, were 100 and 98.9% for LCx of endocervical samples, 52.4 and 100% for PACE2; and 71.4 and 100% for culture. The sensitivity/specificity of LCx for midstream clean-catch urines was 66.7/98.5%. The apparent prevalence of C. trachomatis in our population was 10.2%. These data indicate that among the methods tested, LCx of endocervical samples had the highest sensitivity for C. trachomatis in this population. The sensitivity of the urine LCx assay using midstream clean-catch collected urines was considerably less than that reported in other studies that used first-void urines but was higher than that of PACE2.