Chlamydia trachomatis in sexually active teenage girls. Factors related to genital chlamydial infection: a prospective study

Innate and adaptive anti-HIV immune responses in the female reproductive tract

The mucosal surface of the female reproductive tract (FRT) is the primary site of transmission for a plethora of sexually transmitted infections, including human immunodeficiency virus (HIV), that represent a significant burden upon womens' health worldwide. However, fundamental aspects of innate and adaptive immune protection against HIV infection in the FRT are poorly understood. The FRT immune system is regulated by the cyclical changes of the sex hormones estradiol and progesterone across the menstrual cycle, which as we have hypothesized, leads to the creation of a window of vulnerability during the secretory stage of the menstrual cycle, when the risk of HIV transmission is increased. The goal of this review is to summarize the multiple levels of protection against HIV infection in the FRT, the contribution of different cell types including epithelial cells, macrophages, T cells, and dendritic cells to this, and their regulation by estradiol and progesterone. Understanding the unique immune environment in the FRT will allow for the potential development of novel therapeutic interventions such as vaccines and microbicides that may reduce or prevent HIV transmission in women.

Hormonal contraception and area of cervical ectopy: a longitudinal assessment

BACKGROUND

The effect of combined oral contraceptives (COCs) and depot-medroxyprogesterone acetate (DMPA) on the area of cervical ectopy is not well understood.

STUDY DESIGN

From 1996 to 1999, we recruited women not using hormonal contraception from two family planning centers in Baltimore, MD. Upon study entry and 3, 6 and 12 months after the initial visit, participants were interviewed and received visual cervical examinations with photography. Ectopy was measured from digitized photographs and was analyzed both continuously and categorically (small [≤0.48 cm(2)] vs. large [>0.48 cm(2)]).

RESULTS

Of 1003 enrolled women, 802 returned for at least one follow-up visit. At 12 months, the numbers of women using COCs, DMPA or no hormonal method at least 50% of the time since the prior visit were 230, 76 and 229, respectively. After multivariable adjustment, COC use (vs. no hormonal use) was associated with large area of ectopy (odds ratio [OR]: 1.8, 95% confidence interval [CI]: 1.0-3.3). No significant relationship was observed between DMPA and large area of ectopy (OR: 0.5, 95% CI: 0.2-1.3). The incidence of large area of ectopy by contraceptive exposure (COC, DMPA or no hormonal method) was 17.4 (CI: 11.8-24.6), 10.9 (CI: 4.4-22.4) and 4.6 (CI: 2.2-8.4) per 100 woman-years, respectively.

CONCLUSIONS

Use of COCs, but not DMPA, was associated with large area of cervical ectopy. Area of ectopy at baseline was the strongest predictor of area of ectopy at follow-up.

Hormonal contraception and HIV acquisition: reanalysis using marginal structural modeling

Hormonal contraceptives are used widely worldwide; their effect on HIV acquisition remains unresolved. We reanalyzed data from the Hormonal Contraception and HIV Study using marginal structural modeling to reduce selection bias due to time-dependent confounding. Replicating our original analysis closely, we found that depo-medroxyprogesterone acetate (DMPA) but not combined oral contraceptive (COC) was associated with increased HIV acquisition. Also, young (18-24 years) but not older women who used DMPA and COCs were at increased HIV risk.

Sexually transmitted and other genital infections in women with cervical human papillomavirus infection

Objective: We investigated possible correlations between latent cervical human papillomavirus infection (CHPI) and other sexually transmitted diseases (STDs).

Methods: Of 972 randomly selected women attending 2 family planning clinics and a youth clinic who had agreed to participate in a study concerning STDs, 66 (6.8%) had latent CHPI.

Results: An association was found between latent CHPI on one hand and a history of genital chlamydial infection, gonorrhea, recurrent vaginal candidiasis, cervicitis, or pelvic inflammatory disease (PID) on the other, while no correlation between latent CHPI and coexistent STDs was found. No correlation of latent CHPI to either current or past genital warts was noted. In multifactorial analyses, which included the lifetime number of sexual partners and age at first intercourse, we found that all significant associations except a history of gonorrhea vanished.

Conclusions: In this study population, screening for other current STDs in women with latent CHPI would be of limited value.

Immune pathogenesis of asymptomatic chlamydia trachomatis infections in the female genital tract

Chlamydia trachomatis (CT) infections of the female genital tract, although frequently asymptomatic, are a major cause of fallopian-tube occlusion and infertility. Early stage pregnancy loss may also be due to an unsuspected and undetected CT infection. In vitro and in vivo studies have demonstrated that this organism can persist in the female genital tract in a form undetectable by culture. The mechanism of tubal damage as well as the rejection of an embryo may involve an initial immune sensitization to the CT 60 kD heat shock protein (HSP), followed by a reactivation of HSP-sensitized lymphocytes in response to the human HSP and the subsequent release of inflammatory cytokines. The periodic induction of human HSP expression by various microorganisms or by noninfectious mechanisms in the fallopian tubes of women sensitized to the CT HSP may eventually result in tubal scarring and occlusion. Similarly, an immune response to human HSP expression during the early stages of pregnancy may interfere with the immune regulatory mechanisms required for the maintenance of a semiallogeneic embryo.

Risk factors for genital chlamydial infection

OBJECTIVE

To discuss the occurrence of genital chlamydia in developed countries and review the literature assessing the potential risk factors for this sexually transmitted disease.

DATA SOURCES

A MEDLINE search was performed for all English citations from 1985 to 2000 that contain the keywords "Chlamydia trachomatis", "chlamydial infections", "risk factors" and "sex behaviour". All relevant references cited in articles that were obtained from the search were also included.

DATA EXTRACTION

ALL ARTICLES OBTAINED FROM THE ABOVE SOURCES WERE EXAMINED, AND WERE INCLUDED IN THE REVIEW IF THEY MET THE FOLLOWING CRITERIA: primary study examining sociodemographic or behavioural risk factors associated with genital chlamydial infection using multivariate analysis; study subjects 12 years of age and older; and study setting in a developed country.

DATA SYNTHESIS AND CONCLUSIONS

Genital chlamydial infection has become the most commonly reported bacterial infection in North America over the past decade. Thirty-eight cross-sectional studies and six cohort studies were included in the present review. Most studies demonstrated that young men and women are at higher risk of being infected with chlamydia than older subjects. Chlamydia seems to be found in a diverse group of people, and unlike gonorrhea, is not concentrated in low income, minority core groups with high rates of partner change. However, a number of studies have shown that communities with well-established control programs are beginning to demonstrate this pattern. There is no clear evidence that chlamydia is associated with type of partners, contraceptive use, or age at first intercourse. Future research should follow this sexually transmitted disease as it evolves through the epidemiological stages to ensure that preventive and treatment services are reaching those people who are most likely to be infected.