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

Behavioural sources of repeat Chlamydia trachomatis infections: importance of different sex partners

OBJECTIVE

To examine sources of repeat Chlamydia trachomatis infections using behavioural and molecular methods.

METHODS

Women with C. trachomatis had baseline and 4-month follow-up visits consisting of behavioural surveys and genotyping of C. trachomatis. Frequencies and population-attributable risk percentages (PAR%) were estimated for possible sources of repeat infections including sex partners not known to be treated, new sex partners, and sex partners not known to be monogamous. Women with different genotypes at baseline and follow-up were classified as different partner sources of infection.

RESULTS

The cumulative incidence of repeat infections in the sample (n=183) was 13% (95% CI 8% to 18%). Predictors of repeat infections included younger age and continued sex with a partner not known to be treated. Frequencies of having partners not known to be treated, new partners, or partners not known to be monogamous at follow-up were 21% (95% CI 15% to 27%), 37% (95% CI 30% to 44%) and 33% (95% CI 28% to 41%), respectively. The PAR% for having a partner not known to be treated was 26% (95% CI 3% to 49%) and for having a new sex partner was 21% (95% CI 0% to 50%). Among eight patients with available genotypes at baseline and follow-up, five had different genotypes and were classified as having a different partner source of infection.

CONCLUSIONS

Different sex partner sources of repeat C. trachomatis infections other than untreated sex partners may contribute substantially to the burden of repeat infections.

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae and repeat infection among pregnant urban adolescents

BACKGROUND

Negative maternal and fetal consequences associated with Chlamydia trachomatis and Neisseria gonorrhoeae during pregnancy make diagnosis essential. The Centers for Disease Control and Prevention recommend routine screening for sexually transmitted infections at the first prenatal visit, and third trimester repeat screening, specifically for C. trachomatis, is recommended for women under age 25 or at increased infection risk. The effect of repeat screening on diagnosis during pregnancy is not well documented among adolescents.

METHODS

A prospective cohort of 125 pregnant adolescents with at least one prenatal screening for C. trachomatis and N. gonorrhoeae was analyzed. All participants received prenatal care and delivered at one urban teaching hospital in Washington, DC. Screening results were documented for both sexually transmitted infections. Descriptive and univariate analyses were performed to describe disease prevalence.

RESULTS

Of pregnant adolescents, 31% were diagnosed with either C. trachomatis or N. gonorrhoeae infection during pregnancy. Of the 75% (95/125) of patients who had more than one screening test, 11% (10/95) had a reinfection, and 7% (7/95) had a new infection on repeat testing. Nine percent (9/95) had recurrent C. trachomatis, whereas 4% (4/95) had a new diagnosis. Three percent (3/95) had recurrent N. gonorrhoeae, whereas 4% (4/95) had a new diagnosis. Some experienced coinfection at either initial or repeat testing.

CONCLUSIONS

Screening for C. trachomatis and N. gonorrhoeae is recommended during pregnancy. In this sample of pregnant adolescents, the overall high incidence and recurrence of C. trachomatis and N. gonorrhoeae support Centers for Disease Control and Prevention screening and rescreening recommendations, regardless of initial test results.

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.

Murine Chlamydia trachomatis genital infection is unaltered by depletion of CD4+ T cells and diminished adaptive immunity

Chlamydia muridarum and Chlamydia trachomatis mouse models of genital infection have been used to study chlamydial immunity and vaccine development. To assess the protective role of CD4(+) T cells in resolving C. trachomatis and C. muridarum genital tract infections, we used the female mouse model and evaluated infection in the presence and absence of CD4(+) T cells. In contrast to C. muridarum infection, C. trachomatis infection was unaltered in the absence of CD4(+) T cells. Mice infected with C. trachomatis developed protective immunity to re-challenge, but unlike C. muridarum infection, optimum resistance required multiple infectious challenges, despite the generation of adaptive serum and local chlamydial specific immune responses. Thus, understanding the chlamydial pathogenic and host immunologic factors that result in a diminished protective role for CD4(+) T cells in C. trachomatis murine infection might lead to new insights important to human immunity and vaccine development.

Improving Chlamydia trachomatis retesting rates by mailed self-collection kit

Background To assess a mailed self-collection kit for chlamydia testing as an intervention to increase post-treatment retesting rates. Methods: This prospective intervention study took place at a sexual health clinic in Townsville, North Queensland (Australia) between 2006 and 2008. The intervention consisted of offering to mail a self-collection kit for retesting 3 months after treatment. The achieved retesting rates were compared to those from the previous year and to concurrent controls who did not participate in the intervention. Both control groups received standard advice on retesting. Results: Of the 46 participants in the intervention group, 34.8% returned the sample for retesting 3 to 4 months after initial treatment, in comparison to 6.8% of the historic control groups (n = 206) and 1.4% of the concurrent control group (n = 142) (P < 0.001, respectively). Conclusions: Retesting rates for Chlamydia trachomatis were substantially and significantly improved using the mailed self-collection kit evidencing that the kit could deliver a much needed intervention to improve notoriously low retesting rates.

The impact of community-based sexually transmitted infection screening results on sexual risk behaviors of African American adolescents

PURPOSE

To examine the effect of a community-based sexually transmitted infection (STI) screening program on sexual risk behavior among African American adolescents. We hypothesized that adolescents testing positive for an STI and receiving post-test counseling would reduce risky sexual practices, whereas STI-negative adolescents would show little or no change in protective sexual behavior after screening.

METHODS

From August 2006 to January 2008, we recruited 636 sexually active African American adolescents (age, 14-17) from community-based organizations in two mid-sized U.S. cities with high STI prevalence. Participants were screened for three STIs (gonorrhea, chlamydia, and trichomoniasis) and completed an audio computer-assisted self-interview. Youth who tested positive for an STI (6.6%) received treatment and counseling. Youth testing negative received no further intervention. Approximately 85% of participants completed 3- and 6-month follow-up assessments. Generalized estimating equations determined the effects of STI screening on adolescents' number of sexual partners and occurrence of unprotected sex.

RESULTS

Adolescents who tested positive for an STI reduced their number of vaginal and oral sex partners and the probability of unprotected sex. STI-negative adolescents demonstrated no change for numbers of partners or unprotected sex.

CONCLUSIONS

Community-based STI screening can help to reduce sexual risk behavior in youth who test positive for STIs. Alternative approaches will be needed to reduce risk behavior in youth who test negative but who are nevertheless at risk for acquiring an STI.