Repeat Chlamydia trachomatis infection in women: analysis through a surveillance case registry in Washington State, 1993-1998

Longitudinal association of gonorrhea and bacterial vaginosis with repeat chlamydia diagnoses among U.S. Army women: a retrospective cohort analysis

BACKGROUND

Historically, sexually transmitted infections have affected the health of the U.S. military. To determine whether gonorrhea, bacterial vaginosis, genital herpes, and trichomoniasis are predictors of repeat chlamydia diagnoses among U.S. Army women, medical data reported into the Defense Medical Surveillance System during the 2006-2012 period were analyzed.

METHODS

For all inpatient and outpatient medical records, the first and second International Classification of Diseases, version 9 (ICD-9) diagnostic positions were reviewed for each chlamydia case to determine the occurrence of repeat diagnoses. The Andersen-Gill regression model, an extension of the Cox model for multiple failure-time data, was used to study associations between predictors and repeat chlamydia diagnoses.

RESULTS

Among 28,201 women with a first chlamydia diagnosis, 5145 (18.2%), 1163 (4.1%), 267 (0.9%), and 88 (0.3%) had one, two, three, and four or more repeat diagnoses, respectively. Overall, the incidence of repeat chlamydia was 8.31 cases per 100 person-years, with a median follow-up time of 3.39 years. Gonorrhea (hazard ratio (HR) = 1.58, 95% CI: 1.44-1.73) and bacterial vaginosis (HR = 1.40, 95% CI: 1.09-1.79) were significant predictors for repeat chlamydia. These estimated hazard ratios were attenuated, but remained significant, after controlling for age, race/ethnicity, marital status, and military rank. No significant association was found for genital herpes (HR = 1.13, 95% CI: 0.55-2.29) and trichomoniasis (HR = 1.43, 95% CI: 0.43-4.68).

CONCLUSIONS

This large cohort study suggests that gonorrhea and bacterial vaginosis were associated with repeat chlamydia diagnoses among U.S. Army women. These findings can be used in formulating new interventions to prevent repeat chlamydia diagnoses.

Risk Factors for Incident and Redetected Chlamydia trachomatis Infection in Women: Results of a Population-Based Cohort Study

OBJECTIVES

To investigate risk factors for incident and redetected Chlamydia trachomatis (CT) infection in women, including the role of high-risk human papillomavirus (HPV).

METHODS

In this population-based, prospective cohort study conducted in Copenhagen, Denmark, 10,729 women aged 20 to 29 years were tested for CT and HPV DNA and provided information on sexual and health behavior at baseline. Of these, 7998 (74.5%) participated in a follow-up visit 2 years later with identical data collection. We used logistic regression to investigate risk factors for incident and redetected CT infection at follow-up.

RESULTS

Among CT DNA negative women at baseline (n = 7529), 106 (1.4%) were CT DNA positive at follow-up (incident infection). Increasing number of sexual partners during follow-up (odds ratio [OR], 1.07 per partner; 95% confidence interval (CI), 1.02-1.11), low educational level (OR, 1.69; 95% CI, 1.11-2.56; for basic education vs. high school or higher), and high-risk HPV positivity at baseline (OR, 1.66; 95% CI, 1.06-2.58) were risk factors for incident infection, whereas older age (OR, 0.86 per year increase; 95% CI, 0.80-0.93) and condom use (OR, 0.60; 95% CI, 0.38-0.94) were associated with reduced risk. Among CT DNA positive women at baseline (n = 469), 108 (23.0%) tested positive at follow-up (redetected infection). We found no statistically significant associations between age, educational level, sexual behavior, smoking, or high-risk HPV status and the risk for redetected CT.

CONCLUSION

Young age, low educational level, high number of sexual partners, failure to use condoms, and high-risk HPV positivity are associated with increased risk for incident CT infection. These findings may guide the development of targeted CT prevention strategies, including screening and information campaigns.

An exploratory analysis of individuals with multiple episodes of different reportable diseases, Montreal, 1990-2012

OBJECTIVES

Studies of public health reporting have only examined multiple episodes of the same communicable disease within an individual. We aimed to characterize Montreal residents with multiple reportable disease episodes from 1990 to 2012, while accounting for all types of reportable diseases.

STUDY DESIGN

Retrospective cohort study.

METHODS

We performed an exploratory analysis using descriptive statistics, contingency tables, and logistic regression.

RESULTS

There were 157,839 individuals with at least one disease report and a total of 179,455 disease reports. The 9.8% of subjects with more than one episode accounted for 20.7% of all reported episodes. Among subjects with four or fewer episodes, 54.0% were women, while 74.3% of subjects with five or more episodes were men. Subjects with multiple episodes were more likely to be reported for sexually transmitted infections than were persons with a single episode [difference of proportions: 10.4% (95% CI: 10.0%-10.9%)] and to reside in the neighbourhood encompassing Montreal's gay village.

CONCLUSIONS

Individuals with multiple communicable disease reports place a large burden on public health officials. These results may help guide investigation and prevention efforts to reduce the number of excess episodes.

Sexually transmitted disease partner notification among African-American, adolescent women

OBJECTIVE

To better understand preferences and practices regarding partner notification of sexually transmitted infection (STI) among female, African-American adolescents.

METHODS

Participants completed a questionnaire and STI testing at baseline. Those diagnosed with Chlamydia or gonorrhea were recruited for a follow-up study, involving another questionnaire and repeat STI testing after three months.

RESULTS

At baseline, most participants (85.1%) preferred to tell their partner about an STI diagnosis themselves instead of having a health care provider inform him, and 71.0% preferred to bring their partner for clinic treatment instead of giving him pills or a prescription. Two-thirds of participants were classified as having high self-efficacy for partner notification of a positive STI diagnosis. In the multivariable analysis, older participants and those with fewer lifetime sexual partners were more likely to have high self-efficacy. Ninety-three participants (26.6%) had Chlamydia or gonorrhea and, of this subset, 55 participated in the follow-up study. Most adolescents in the follow-up study (76.4%) notified their partner about their infection.

CONCLUSION

Although participants were willing to use most methods of partner notification, most preferred to tell partners themselves and few preferred expedited partner therapy. Traditional methods for partner notification and treatment may not be adequate for all adolescents in this population.

Chlamydia trachomatis infection rates among a cohort of mobile soldiers stationed at Fort Bragg, North Carolina, 2005-2010

Background

Fort Bragg, a large Army installation with reported high Chlamydia trachomatis (Ct) infection rates, is characterized by a highly mobile population and a surrounding Ct-endemic community. We assessed the rates of Ct incidence and recurrence among the installation’s active component Army personnel and determined the association of soldier transience, sociodemographic factors, and history of sexually transmitted infection (STI) with these rates.

Methods

A cohort of soldiers stationed at Fort Bragg during 2005 to mid-2010 was followed for incident and recurrent Ct infection using laboratory-confirmed reportable disease data. Linkage to demographic and administrative data permitted multivariate analysis to determine association of covariates with initial or recurrent infection.

Results

Among 67,425 soldiers, 2,198 (3.3%) contracted an incident Ct infection (crude incidence, 21.7 per 1,000 person-years). Among soldiers followed for incident infection, 223 (10.6%, crude incidence 110.8 per 1,000 person-years) contracted a recurrent Ct infection. Being female, of lower rank, under 26 years of age, of non-white race, single, or with a high school diploma or less was significantly associated with incident Ct infection. Having breaks in duty or having deployments during follow-up was associated with a lower infection rate. Among women, having prior deployments was associated with a lower rate of both incident and recurrent infection. Specifically associated with recurrent infection in women was age under 21 years or no education beyond high school.

Conclusions

This analysis reaffirms risk factors for Ct infection determined in other studies. In addition, infection risk was lower for more mobile soldiers and tied to the specific location of their regular duty assignment. The findings support the STI prevention efforts at Fort Bragg and the surrounding community, regardless of how often or for how long soldiers have deployed for military operations.

Prevalence and risk factors for Chlamydia trachomatis infection among young Thai men in 2008-2009

BACKGROUND

Asymptomatic Chlamydia trachomatis (CT) infection and other sexually transmitted infections in men potentially contribute significantly in sustaining the spread of the infection. To describe the distribution and related sexual behaviors, we conducted a cross-sectional study among young Thai men using a (1:30) systematic sampling of all newly inducted military conscripts in Thailand.

METHODS

In November 2008 and May 2009, participants' urine and serum samples were tested for CT and Neisseria gonorrhoeae, using a multiplex polymerase chain reaction technique, and serologic testing for Treponema pallidum and HIV-1 was done. Information on demographic data and risk behaviors was obtained by a self-administered questionnaire.

RESULTS

The overall prevalence rates of CT, N. gonorrhoeae, HIV-1, and syphilis infection were 7.9%, 0.9%, 0.5%, 0.05%, respectively. The risk factors for CT infection were living in the upper north region (adjusted rate ratios [95% confidence interval], 2.13 [1.39-3.26]), having had 4 or more sexual partners (2.14 [1.48-3.09]), graduation from a vocational school (1.66 [1.14-2.41]), inconsistent condom use (1.48 [1.05-2.08]), unemployment (1.82 [1.06-3.12]), and age 21 years or younger (1.63 [1.01-2.63]).

CONCLUSIONS

The prevalence of CT infection among young male military conscripts was high, especially among men from upper northern Thailand. Multiple sexual partners, graduation from a vocational school, inconsistent condom use, unemployment before the military induction, and younger age were independently associated with the CT infection among young Thai men. These data will be useful to develop more effective public health interventions to prevent, detect, and treat sexually transmitted infections among young men in Thailand.

Concurrent patient-partner treatment in pregnancy: an alternative to expedited partner therapy?

BACKGROUND

Concurrent patient-partner treatment (CPPT) is the provision of treatment to the index patient and their sexual partner(s) and appears to be an effective method of preventing repeat sexually transmitted infections. The objectives of the study were to determine whether CPPT reduces the prevalence of a positive test of cure (TOC) for chlamydia and/or gonorrhea infection in pregnant women.

METHODS

We conducted an observational cohort study of 241 pregnant women aged 15 to 40 years diagnosed with chlamydia and/or gonorrhea receiving prenatal care at an urban teaching hospital. Pregnant women and their sexual partner(s) received CPPT consisting of azithromycin and/or cefpodoxime for treatment of chlamydia and/or gonorrhea infection, respectively, or patient referral consisting of an antibiotic prescription to the pregnant woman and advice for partner screening and therapy. Odds ratios (ORs) and survival estimates were calculated by χ or Fisher exact test, multivariable logistic regression, and Kaplan-Meier.

RESULTS

Forty-five pregnant women with chlamydia and/or gonorrhea received CPPT and were less likely to have a positive TOC (OR = 0; P < 0.001) and repeat positive chlamydia infection (OR = 0; P = 0.12) compared with 196 women that were treated and counseled on the patient referral treatment strategy for their sexual partners. CPPT shortened the median time to cure (4.4 weeks, standard deviation = 2.3) versus standard patient referral (5.1 weeks, standard deviation = 5.2). There were no repeat positive chlamydia infections in the CPPT group compared with 19 (18.1%) in the patient referral group.

CONCLUSIONS

CPPT decreased the prevalence of a positive TOC for chlamydia infection among pregnant women.

Chlamydia trachomatis incidence and re-infection among young women--behavioural and microbiological characteristics

BACKGROUND

This study aimed to estimate rates of chlamydia incidence and re-infection and to investigate the dynamics of chlamydia organism load in prevalent, incident and re-infections among young Australian women.

METHODS

1,116 women aged 16 to 25 years were recruited from primary care clinics in Australia. Vaginal swabs were collected at 3 to 6 month intervals for chlamydia testing. Chlamydia organism load was measured by quantitative PCR.

RESULTS

There were 47 incident cases of chlamydia diagnosed and 1,056.34 person years of follow up with a rate of 4.4 per 100 person years (95% CI: 3.3, 5.9). Incident infection was associated with being aged 16 to 20 years [RR = 3.7 (95%CI: 1.9, 7.1)], being employed [RR = 2.4 (95%CI: 1.1, 4.9)] and having two or more new sex partners [RR = 5.5 (95%CI: 2.6, 11.7)]. Recent antibiotic use was associated with a reduced incidence [RR:0.1 (95%CI: 0.0, 0.5)]. There were 14 re-infections with a rate of 22.3 per 100 person years (95%CI: 13.2, 37.6). The median time to re-infection was 4.6 months. Organism load was higher for prevalent than incident infections (p<0.01) and for prevalent than re-infections (p<0.01).

CONCLUSIONS

Chlamydia is common among young women and a high proportion of women are re-infected within a short period of time, highlighting the need for effective partner treatment and repeat testing. The difference in organism load between prevalent and incident infections suggests prevalent infection may be more important for ongoing transmission of chlamydia.

Upsurge of chlamydial reinfection in a large Canadian city: an indication of suboptimal chlamydia screening practices?

OBJECTIVES

Given the limited knowledge on chlamydial reinfection (CR) in Canada, we examined the extent and predictors of CR in Montréal, a large Canadian city.

METHODS

We retrospectively studied all Montréal residents aged > or =10 years for whom > or =1 laboratory-confirmed chlamydial infection was reported to the public health department between 1988 and 2007 (n = 44,580). Each person was passively followed for two years after baseline infection or until reinfection. Socio-demographic factors and histories of other notifiable diseases were examined as potential predictors. Cox multivariate regression was used to model the time to CR. Survival analyses were stratified by age group (<25 vs. > or =25 years).

RESULTS

We estimated an overall two-year CR rate of 6.4%, an incidence density of 3.5 per 100 person-years, and a median time to reinfection of nine months. CR significantly increased over time. Among persons <25 years, reinfection was significantly more likely among females [adjusted hazard ratio (AHR): 1.58] and younger participants (10-14 years: AHR: 2.98; 15-19 years: AHR: 1.81). Residing within the South Central sector was deleterious for six months following initial infection after which it became protective. Among persons > or =25 years, a history of sexually transmitted infections increased the risk of reinfection (AHR: 1.79).

CONCLUSION

CR is a significant and growing problem in Montreal. The current recommendation for a single repeat screening six months posttreatment might be usefully complemented with additional screenings. Our results also underscore the importance of screening high-risk populations, particularly young women.

Repeated Chlamydia trachomatis genital infections in adolescent women

BACKGROUND

Repeated Chlamydia trachomatis infections are common among young sexually active women. The relative frequency of reinfection and antibiotic treatment failure is undefined.

METHODS

Adolescent women enrolled in a longitudinal cohort had behavioral and sexually transmitted infection assessments performed every 3 months, including amplification tests for C. trachomatis, ompA genotyping, and interviews and diary entries to document sex partner-specific coitus and event-specific condom use. Repeated infections were classified as reinfection or treatment failure by use of an algorithm. All infections for which treatment outcomes were known were used to estimate the effectiveness of antibiotic use.

RESULTS

We observed 478 episodes of infection among 210 study participants; 176 women remained uninfected. The incidence rate was 34 episodes/100 woman-years. Of the women who were infected, 121 experienced 1 repeated infections, forming 268 episode pairs; 183 pairs had complete data available and were classified using the algorithm. Of the repeated infections, 84.2% were definite, probable, or possible reinfections; 13.7% were probable or possible treatment failures; and 2.2% persisted without documented treatment. For 318 evaluable infections, we estimated 92.2% effectiveness of antibiotic use.

CONCLUSIONS

Most repeated chlamydial infections in this high-incidence cohort were reinfections, but repeated infections resulting from treatment failures occurred as well. Our results have implications for male screening and partner notification programs and suggest the need for improved antibiotic therapies.

Repeat infection with Chlamydia and gonorrhea among females: a systematic review of the literature

Determining the magnitude of chlamydia and gonorrhea reinfection is critical to inform evidence-based clinical practice guidelines related to retesting after treatment. PubMed was used to identify peer-reviewed English language studies published in the past 30 years that estimated reinfection rates among females treated for chlamydia or gonorrhea. Included in this analysis were original studies conducted in the United States and other industrialized countries that reported data on chlamydia or gonorrhea reinfection in females. Studies were stratified into 3 tiers based on study design. Reinfection rates were examined in relation to the organism, study design, length of follow-up, and population characteristics. Of the 47 studies included, 16 were active cohort (Tier 1), 15 passive cohort (Tier 2), and 16 disease registry (Tier 3) studies. The overall median proportion of females reinfected with chlamydia was 13.9% (n = 38 studies). Modeled chlamydia reinfection within 12 months demonstrated peak rates of 19% to 20% at 8 to 10 months. The overall median proportion of females reinfected with gonorrhea was 11.7% (n = 17 studies). Younger age was associated with higher rates of both chlamydia and gonorrhea reinfection. High rates of reinfection with chlamydia and gonorrhea among females, along with practical considerations, warrant retesting 3 to 6 months after treatment of the initial infection. Further research should investigate effective interventions to reduce reinfection and to increase retesting.

Focus-on-Teens, sexual risk-reduction intervention for high-school adolescents: impact on knowledge, change of risk-behaviours, and prevalence of sexually transmitted diseases

A community-based intervention, Focus-on-Kids (FOK) has demonstrated risk-behaviour reduction of urban youth. We modified FOK to Focus-on-Teens (FOT) for high schools. High school adolescents (n=1190) were enrolled over successive school semesters. The small-group sessions were presented during the school-lunch hours. Confidential surveys were conducted at baseline, immediate, six-, and 12-month postintervention for demographics, parental communication/monitoring, sexual risk behaviours and sexually transmitted diseases (STDs)/HIV/condom-usage knowledge. Sexually active participants were encouraged to volunteer for urine-based STDs testing at the School-Based Health Centres. Many (47.4%) students reported having had sexual intercourse at baseline. Overall behaviours changed towards 'safer' sex behaviours (intent-to-use and using condoms, communicating with partner/parents about sex/condoms/STDs) with time (P<0.05). Proportion of students with complete correct knowledge of STDs/HIV increased to 88% at time 4 from 80% at baseline after adjusting for age, gender and sexual activity (P<0.05). High prevalence of STDs was detected in 875 participants who reported for urine testing at time 1: trichomonas, 11.8%; chlamydia, 10.1% and gonorrhoea, 4.1%. Prevalence decreased significantly for 310 participants who re-tested; chlamydia: 27.4% to 6.1% and gonorrhoea: 11.3% to 3.2%. FOT was successfully implemented as an STDs/HIV risk-reduction intervention. Sustained improvements of knowledge about STDs/HIV/condom usage, decreases in sexual risk behaviours supported the effectiveness of this intervention.

Chlamydia trachomatis reinfection rates among female adolescents seeking rescreening in school-based health centers

BACKGROUND

Chlamydia trachomatis (CT) infections are common among adolescents attending high and middle schools. The study objective was to determine the reinfection rates of CT for females attending school-based health centers.

METHODS

Adolescents attending school-based health centers who reported they were sexually active were screened for CT using nucleic acid amplification tests on cervical or urine samples. Between 1996 and 2003, 10,609 female students were tested. The overall annual prevalence for unduplicated students in a calendar year ranged from 15.1% to 19.5%. Reinfection was defined as a positive test result occurring between 30 and 365 days after an initial positive result.

RESULTS

There were 897 female students who tested positive for CT and returned for at least 1 subsequent test between 30 and 365 days later. Of these, 236 had 1 or more subsequent positive tests for a cumulative incidence of reinfection in 1 year of 26.3% (95% confidence interval = 23.4-29.2%). Young age at first infection was significantly associated with increased risk of subsequent infection (P <0.01). Across sites, the cumulative incidence of reinfection in these female students ranged from 14.3% to 38.9%.

CONCLUSIONS

The chlamydia cumulative incidence of reinfection in these female adolescents attending high and middle schools was high and supports the Centers for Disease Control and Prevention recommendation to screen adolescents frequently, especially those with a history of a previous chlamydia infection.

Long-term effects of natural amino acids on infection with Chlamydia trachomatis

Supplementation of culture media with leucine, isoleucine, methionine, or phenylalanine was previously found to inhibit Chlamydia trachomatis growth in HEp-2 cells. Here, we investigated the long-term effects of these additives on C. trachomatis infection in the same cell model. Amino acid addition 30h post-infection (pi) effectively suppressed the generation of infectious progeny monitored for 10 days pi. With the exception of phenylalanine, amino acid treatment beginning at 2h pi for up to 15 days led to a complete lack of infectious progeny. Phenylalanine treatment resulted in residual minimal infectivity. In extended supplementation experiments, very small aberrant chlamydial inclusions formed, whose numbers decreased considerably over time, and the production of infectious chlamydiae could not be rescued even upon amino acid withdrawal. Interestingly, a state of chlamydial persistence was induced under these conditions, as 16S rRNA transcripts were detected throughout treatment. However, expression of several key chlamydial genes including omp1, groEL, omcB, and those functioning for chlamydial DNA replication and cytokinesis was generally very low or even undetected, particularly in monolayers treated with Leu, Ile, or Met. These data revealed a capacity of certain amino acids to eliminate infectious chlamydial progeny. Additionally, supplementation of certain amino acids resulted in the formation of a small persistent population. Extrapolating from these findings may help formulate an anti-chlamydial treatment based on nutritional elements.

Management of uncomplicated Chlamydia trachomatis infections in adolescents and adults: evidence reviewed for the 2006 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines

In April 2005, in preparation for the 2006 Centers for Disease Control and Prevention (CDC) sexually transmitted diseases (STD) treatment guidelines, the CDC convened an advisory group to examine recent abstracts and published literature addressing management of Chlamydia trachomatis infections in adolescents and adults. Key questions were posed and answered on the basis of quality of evidence and expert opinion. Clinical trials continue to demonstrate equivalent efficacy and tolerability of azithromycin and doxycycline regimens, and both remain recommended as first-line therapy in nonpregnant individuals. More data and clinical experience are available to support the efficacy, safety, and tolerability of azithromycin in pregnant women, and, in the upcoming guidelines, azithromycin will be recommended as first-line therapy for such patients. Evidence is building that expedited partner therapy (EPT), with provision of treatment or a prescription, may be just as effective as or more effective than standard partner referral in ensuring partner treatment and preventing chlamydia recurrence in women. Although there are more studies needed and barriers to be addressed before its widespread use, EPT will be recommended as an option for partner management.

Chlamydial and gonococcal reinfection among men: a systematic review of data to evaluate the need for retesting

This study aimed to systematically review and describe the evidence on chlamydia and gonorrhoea reinfection among men, and to evaluate the need for retesting recommendations in men. PubMed and STI conference abstract books from January 1995 to October 2006 were searched to identify studies on chlamydia and gonorrhoea reinfection among men using chlamydia and gonorrhoea nucleic acid amplification tests or gonorrhoea culture. Studies were categorised as using either active or passive follow-up methods. The proportions of chlamydial and gonococcal reinfection among men were calculated for each study and summary medians were reported. Repeat chlamydia infection among men had a median reinfection probability of 11.3%. Repeat gonorrhoea infection among men had a median reinfection probability of 7.0%. Studies with active follow-up had moderate rates of chlamydia and gonorrhoea reinfection among men, with respective medians of 10.9% and 7.0%. Studies with passive follow-up had higher proportions of both chlamydia and gonorrhoea reinfections among men, with respective medians of 17.4% and 8.5%. Proportions of chlamydia and gonorrhoea reinfection among men were comparable with those among women. Reinfection among men was strongly associated with previous history of sexually transmitted diseases and younger age, and inconsistently associated with risky sexual behaviour. Substantial repeat chlamydia and gonorrhoea infection rates were found in men comparable with those in women. Retesting recommendations in men are appropriate, given the high rate of reinfection. To optimise retesting guidelines, further research to determine effective retesting methods and establish factors associated with reinfection among men is suggested.

Feasibility and utility of screening adolescent mothers for Chlamydia at their children's health care visits

PURPOSE

Assess the feasibility of offering and barriers to accepting urine-based screening for Chlamydia trachomatis (CT) among asymptomatic adolescent mothers during their children's health care visits.

METHOD

Providers were automatically cued to offer CT-screening to 13 through 21 year old mothers when they opened the child's medical record. Recording the mothers' screening decisions removed the flag for 6 months. Providers were also prompted to assess the perceived importance of CT prevention, likelihood of having CT, and the worst aspect of having CT.

RESULTS

Mothers usually brought their children to the clinic. Hence, providers could act on 97% of the 318 flags they saw. They responded appropriately 75% of the time. Only 96 (42%) of the 229 mothers who were asked agreed to screening. The primary reasons for declining were "monogamous" and "tested within 6 months". Almost everyone said CT was a top preventive health priority, but that they would be surprised if they were infected. Mothers who agreed to screening were less likely to have a child less than 6 months of age (26.0% vs. 57.1%; P < 0.0001). They were also more likely to rate knowledge of partner infidelity (39.4% vs. 13.6%; P = 0.03) and less likely to rate medical problems (15.2% vs. 40.9%; P = 0.01) the worst aspect of having CT. None of the 21 urine samples obtained within 6 months of delivery were positive for CT. Thereafter, 5 (9.1%) of the 55 urines were positive.

CONCLUSIONS

It is feasible and useful to screen adolescent mothers for CT at their children's health care visits. The best way to increase the efficacy and strengthen the impact of urine-based CT-screening in this setting is to initiate testing after the 6th postpartum month and heighten awareness of STD-risk among adolescent mothers.

Patient-Delivered Partner Treatment and Other Partner Management Strategies for Sexually Transmitted Diseases Used by New York City Healthcare Providers

OBJECTIVES

The objectives of this study were to measure frequency and predictors of patient-delivered partner treatment (PDPT) and the frequency of other partner management strategies among New York City healthcare providers (HCPs) as well as to determine whether use of PDPT detracts from other partner management strategies.

STUDY DESIGN

The authors conducted a cross-sectional survey of New York City HCPs.

RESULTS

Frequent patient referral was reported by 93.6% (368 of 393) of healthcare providers; only 20% (80 of 401) reported frequent use of provider referral. Overall, 49.2% (196 of 398) of HCPs reported ever using PDPT and 27.1% (108 of 398) reported using PDPT frequently. HCP specialty, practice setting, duration of practice, report of frequent provider referral practice, and HCP race/ethnicity were the strongest predictors of PDPT use. HCPs reporting PDPT use were more likely to report frequent provider referral than those who had never used PDPT (26.7% vs. 12.6%; P <0.001).

CONCLUSIONS

PDPT use is common and is being used in conjunction with other partner management strategies.

Cervicitis: to treat or not to treat? The role of patient preferences and decision analysis

PURPOSE

Mucopurulent cervicitis is neither a sensitive nor a specific indicator of antibiotic sensitive infection. This analysis examines the positive and negative ramifications of treating cervicitis empirically as a Chlamydial (CT) infection. It begins where prior analyses leave off, with the number of cases of pelvic inflammatory disease (PID) prevented.

METHODS

Three treatments were compared: 1) treat empirically/refer partner; 2) test, treat, and base partner treatment on results; 3) test, base treatment on results. The outcomes were the physical sequelae of PID and the psychological sequelae of being diagnosed with CT in a hypothetical cohort of 500 teenagers with cervicitis, among whom the prevalence of CT averaged 33%, but ranged between 10% and 70%.

RESULTS

At a CT prevalence of 33%, Treatments 1 and 2 prevented three times as many cases of PID-related physical sequelae (n = 14) as Treatment 3 (n = 5). However, to prevent these 14 cases of physical sequelae, with Treatment 1, 163 teens needlessly suffer the psychological sequelae of a false CT diagnosis and with Treatment 2, 101 do so. The ratio of physical sequelae prevented to psychological sequelae caused, changed in relationship to the prevalence of CT, but was always numerically most favorable with Treatment 3. Moreover, it was the only therapeutic approach for which overall morbidity never exceeded the PID-related physical morbidity incurred in the absence of treatment.

CONCLUSIONS

By including the effects of over diagnosing and treating CT, we have demonstrated how the risks and benefits of empiric and nonempiric cervicitis therapy vary in relationship to CT prevalence. Failure to consider both the physical and the psychological aspects of patient well-being may mean that well-intentioned policies to reduce physical morbidity do not result in an overall improvement in health of teenagers.

Partner age not associated with recurrent Chlamydia trachomatis infection, condom use, or partner treatment and referral among adolescent women

PURPOSE

Among adolescent women, having older sexual partners has been associated with initial Chlamydia trachomatis (Ct) infection and high-risk behaviors. This study evaluates the role of older partners in the risk of three outcomes: recurrent Ct, lack of condom use, and nonadherence with partner management (PM) strategies.

METHODS

Female participants aged 14 to 18 years enrolled in a randomized clinical trial of patient-delivered partner treatment (PDPT) with at least one follow-up visit were included in this secondary analysis. Patient- and partner-level data were collected at baseline, one, and four months follow-up. Generalized estimating equations (GEE) and logistic regression were used to examine unadjusted and adjusted associations.

RESULTS

The majority of the 496 women were African-American (63.3%), aged 16 to 18 years (62.3%), and asymptomatic for Ct (66.7%). At baseline, all of the women had laboratory-demonstrated Ct and were treated; they had 622 partners during the last 60 days, 21.4% reported having more than one partner with a mean (SD) of 1.5 (.78) partners per woman, and 46.3% of the partners were at least three years older than the woman. Over follow-up, 16.1% of the women experienced Ct recurrence, in 41.9% of the partnerships a condom was not used at last sex, and 80.6% of women reported giving PM. After adjusting for confounders, having a partner at least three years older was not associated with increased risk of Ct recurrence, lack of condom use, or nonadherence to PM strategies.

CONCLUSIONS

Risk of Ct recurrence, lack of condom use, and nonadherence to PM strategies was not higher among adolescent women with older partners.

Reinfections, Persistent Infections, and New Infections After General Population Screening for Chlamydia trachomatis Infection in The Netherlands

OBJECTIVES

The objectives of this study were to determine the rate of new infections and reinfections or persistent infections with Chlamydia trachomatis to define appropriate screening intervals and to identify risk factors for reinfection.

DESIGN

This was a cross-sectional study among a subsample of participants in a population-based screening.

SETTING

This study was conducted in urban and rural areas in The Netherlands.

PARTICIPANTS

A total of 21,000 15- to 29-year-old women and men were invited for home-based urine testing. One year after the study, a subsample of 299 participants were offered retesting.

MAIN OUTCOME MEASURES

The authors studied the rate of infection with C. trachomatis. Serovar determination was used to potentially discriminate between new infections and reinfections or persistent infections.

RESULTS

Nine C. trachomatis infections were found among 187 responders (4.8% confidence interval, 1.7-7.9). The prevalence was 10.4% (5 of 48) in previous positives and 2.9% (4 of 139) in negatives. Three of 5 repeatedly positive participants were infected with a different C. trachomatis serovar.

CONCLUSIONS

Our study indicates that infected persons found in a systematic, population-based screening should be re-screened within 1 year. Optimal screening intervals still need to be determined.

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.

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.

The infecting dose of Chlamydia muridarum modulates the innate immune response and ascending infection

Murine vaginal infection with the obligate intracellular bacterium Chlamydia muridarum is commonly used as a model for ascending Chlamydia infections of the human female genital tract. Gamma interferon-producing Th1 cells, in concert with other mononuclear infiltrates, primarily mediate antichlamydial immunity. However, many factors modify this response, including the bacterial load. To investigate the manner in which the inoculating dose of C. muridarum modulates a genital infection, we measured innate and adaptive cell numbers, CD4+ lymphocyte cytokine profile, chemokine expression, course of infection, and pathological sequelae in genital tracts of BALB/c mice infected with doses of C. muridarum ranging from 10(4) to 10(7) inclusion-forming units. We found that the influx of both innate and adaptive immune cells responded similarly in the lower genital tract (cervical-vaginal tissues) and upper genital tract (oviduct tissues) to increasing inoculating doses. However, cells expressing the innate markers Gr-1 and CD11c were affected to a greater degree by increasing dose than lymphocytes of the adaptive immune response (Th1, CD4+, CD8+, CD19+), resulting in a change in the balance of innate and adaptive cell numbers to favor innate cells at higher infecting doses. Surprisingly, we detected greater numbers of viable chlamydiae in the oviducts at lower inoculating doses, and the number of organisms appeared to directly correlate with hydrosalpinx formation after both primary infection and repeat infection. Taken together, these data suggest that innate immune cells contribute to control of ascending infection.

Applying a mixed-integer program to model re-screening women who test positive for C. trachomatis infection

We proposed a mixed-integer program to model the management of C. trachomatis infections in women visiting publicly funded family planning clinics. We intended to maximize the number of infected women cured of C. trachomatis infections. The model incorporated screening, re-screening, and treatment options for three age groups with respective age-specific C. trachomatis infection and re-infection rates, two possible test assays, and two possible treatments. Our results showed the total budget had a great impact on the optimal strategy incorporating screening coverage, test selection, and treatment. At any budget level, the strategy that used a relatively small per-patient budget increase to re-screen all women who tested positive 6 months earlier always resulted in curing more infected women and more cost-saving than the strategy that was optimal under the condition of not including a re-screening option.

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.

The impact of ignoring measurement error when estimating sample size for epidemiologic studies

The author presents two examples illustrating the bias in sample-size estimates that can result from ignoring measurement error among study variables. The first example examines the impact of ignoring misclassification of the study's outcome variable on the accuracy of sample-size estimates. In addition, the author outlines a simple yet effective means of adjusting sample-size estimates to account for outcome misclassification. In the second example, the author illustrates the potential for severe underestimation of required sample size in studies using linear regression to evaluate associations between the outcome of interest and an independent variable subject to classical measurement error. The author concludes with a discussion of pertinent literature that might be helpful to study planners interested in adjusting sample-size estimates to account for measurement errors in both outcome and predictor variables.

Patient-delivered partner treatment with azithromycin to prevent repeated Chlamydia trachomatis infection among women: a randomized, controlled trial

BACKGROUND

Repeated infection with C trachomatis increases the risk for serious sequelae: pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain. A substantial proportion of women treated for C trachomatis infection are reinfected by an untreated male sex partner in the first several months after treatment. Effective strategies to ensure partner treatment are needed.

GOAL

The goal of the study was to determine whether repeated infections with C trachomatis can be reduced by giving women doses of azithromycin to deliver to male sex partners.

STUDY DESIGN

A multicenter randomized controlled trial was conducted among 1,787 women aged 14 to 34 years with uncomplicated C trachomatis genital infection diagnosed at family planning, adolescent, sexually transmitted disease, and primary care clinics or emergency or other hospital departments in five US cities. Women treated for infection were randomized to one of two groups: patient-delivered partner treatment (in which they were given a dose of azithromycin to deliver to each sex partner) or self-referral (in which they were asked to refer their sex partners for treatment). The main outcome measure was C trachomatis DNA detected by urine ligase chain reaction (LCR) or polymerase chain reaction (PCR) by 4 months after treatment.

RESULTS

The characteristics of study participants enrolled in each arm were similar except for a small difference in the age distribution. Risk of reinfection was 20% lower among women in the patient-delivered partner treatment arm (87/728; 12%) than among those in the self-referral arm (106/726; 15%); however, this difference was not statistically significant (odds ratio, 0.80; 95% confidence interval, 0.62-1.05; = 0.102). Women in the patient-delivered partner treatment arm reported high compliance with the intervention (82%).

CONCLUSION

Patient-delivered partner treatment for prevention of repeated infection among women is comparable to self-referral and may be an appropriate option for some patients.

Epidemiology of female genital Chlamydia trachomatis infections

The World Health Organization (WHO) has estimated that 92 million new cases of C. trachomatis (Chlamydia trachomatis) infection occur each year. This chapter focuses on the epidemiology of C. trachomatis infection, including the prevalence of infection in high- and low-risk groups, the incidence of infection, and data on secular trends. The evidence on the transmission of infection is reviewed. Risk factors for C. trachomatis infection in women are discussed. The adverse sequelae associated with C. trachomatis infection are described. Areas requiring further research are highlighted.

The role of serology, antibiotic susceptibility testing and serovar determination in genital chlamydial infections

Systemic and local antibodies regularly develop in genital infections caused by Chlamydia trachomatis. Such antibodies cannot be used as a sign of current infection as they often persist for years after the infection has resolved. Chlamydial antibodies have, however, been extremely useful for demonstrating associations between C. trachomatis and clinical conditions such as ectopic pregnancy and tubal factor infertility. In particular, antibodies to the chlamydial heat shock protein 60 predict the presence of tubal scarring.C. trachomatis has been divided into 15 (or 18) serovars, with many genotypes within each serovar. Differences in pathogenicity between serovars have been reported but no general pattern has emerged. Genotyping is a powerful epidemiological tool but is not yet ready for routine clinical use.C. trachomatis infections can be successfully treated by tetracycline or macrolides. Some resistant strains have been reported, causing treatment failures, and the problem of emerging antibiotic resistance cannot be neglected.

Older partners not associated with recurrence among female teenagers infected with Chlamydia trachomatis

BACKGROUND

Chlamydia trachomatis-infected female teenagers with older partners may be less likely to discuss the infection with their partner(s) and to use condoms and therefore may be more likely to get reinfected.

GOAL

To determine if C trachomatis-infected female teenagers with older partners were more likely to be reinfected than those with same-aged partners.

STUDY DESIGN

Females aged 14 years to 18 years who had uncomplicated chlamydial infection, were nonpregnant, attended clinics in five United States cities from June 1995 to May 1997, completed treatment, and resumed sexual activity were observed at 1 and 4 months for interim history and retesting.

RESULTS

Of 225 women studied, 73.3% were black, 34.5% had at least one partner who was 3 or more years older during follow-up, 51.6% reported using a condom at the last sex act with all partners, 13.8% had a recurrent infection, and 47.4% reported they were certain that all of their baseline partners were treated. Partner age was not associated with condom use, certainty of partners' taking medication, or recurrent infections after adjustment for visit.

CONCLUSIONS

Older partners, accounting for approximately one third of all partners, did not increase the risk of reinfection. Given the high risk for recurrence, follow-up testing and enhanced efforts to ensure partner treatment are appropriate for all young women with chlamydial infections.

Effects of azithromycin and rifampin on Chlamydia trachomatis infection in vitro

An in vitro cell culture model was used to investigate the long-term effects of azithromycin, rifampin, and the combination of azithromycin and rifampin on Chlamydia trachomatis infection. Although standard in vitro susceptibility testing indicated efficient inhibition by azithromycin, prolonged treatment did not reveal a clear elimination of chlamydia from host cells. Chlamydia were temporarily arrested in a persistent state, characterized by culture-negative, but viable, metabolically active chlamydia, as demonstrated by the presence of short-lived rRNA transcripts. Additionally, azithromycin induced generation of aberrant inclusions and an altered steady-state level of chlamydial antigens, with the predominance of Hsp60 protein compared to the level of the major outer membrane protein. Treatment with azithromycin finally resulted in suppression of rRNA synthesis. Chlamydial lipopolysaccharide and processed, functional rRNA were detectable throughout the entire incubation period. These in vitro data show a good correlation to those from some recent clinical investigations that have reported on the persistence of chlamydia, despite appropriate antibiotic treatment with azithromycin. Rifampin was highly active by in vitro susceptibility testing, but prolonged exposure to rifampin alone for up to 20 days resulted in the emergence of resistance. No development of resistance to rifampin was observed when chlamydia-infected cells were incubated with a combination of azithromycin and rifampin. This combination was shown to be more efficient than azithromycin alone, in that suppression of rRNA synthesis occurred earlier. Thus, such a combination may prove more useful than azithromycin alone.