Cost-effectiveness of Chlamydia antibody tests in subfertile women

Screening for Chlamydia trachomatis infection among infertile women in Saudi Arabia

BACKGROUND

Chlamydia trachomatis infection is a worldwide-distributed sexually transmitted infection that may lead to infertility.

OBJECTIVES

This study aims to report the prevalence of Chlamydia trachomatis infection among infertile women in Saudi Arabia.

PATIENTS AND METHODS

A community-based study carried out at the obstetrics and gynecology clinic at Jazan General Hospital, Saudi Arabia. The study group included 640 Saudi infertile women who were aged between 18 and 40 years and who attended the gynecology clinic for infertility examination throughout 1 year of study (from July 1, 2011 to June 30, 2012). The randomized control group included 100 Saudi fertile women who attended the obstetrics clinic for routine antenatal care. All recruited women were screened for chlamydia infection by enzyme-linked immunosorbent assay (ELISA) for detection of serum-specific antibodies and then retested by the McCoy cell culture technique.

RESULTS

The prevalence of Chlamydia trachomatis infection among infertile women was high, at 15.0%. The rate of chlamydia infection detected by ELISA was 9.84%, and it was 12.03% by the culture method (P = 0.2443).

CONCLUSION

The high prevalence of Chlamydia trachomatis infection among Saudi infertile women demands a national screening program for early detection among infertile couples. ELISA is available as a simple screening test alternative to the culture method.

Epidemiology of Chlamydia trachomatis infection in women and the cost-effectiveness of screening

BACKGROUND

The majority of Chlamydia trachomatis infections in women are asymptomatic, but may give rise to pelvic inflammatory disease (PID) and tubal infertility. Screening programmes aim at reducing morbidity in individuals by early detection and treatment, and at decreasing the overall prevalence of infection in the population. A number of modelling studies have tried to calculate the threshold prevalence of chlamydia lower genital tract infection above which screening becomes cost-effective. There is considerable debate over the exact complication rates after chlamydia infections, and more precise estimates of PID and tubal infertility are needed, for instance to be inserted in economic models.

METHODS

With reference to key studies and systematic reviews, an overview is provided focusing on the epidemiology of chlamydia infection and the risk-estimates of its late complications.

RESULTS

In the literature, the generally assumed risk of developing PID after lower genital tract chlamydia infection varies considerably, and is up to 30%. For developing tubal infertility after PID the risks are 10-20%. This implies that the risk of test-positive women of developing tubal infertility would range between 0.1 and 6%. We included chlamydia IgG antibody testing in a model and estimated a risk of tubal infertility up to 4.6%.

CONCLUSION

The risk of developing late complications after chlamydia lower genital tract infection appears low. High quality RCTs dealing with the transition from cervicitis to infertility are needed to broaden the evidence. In screening programmes, chlamydia antibody testing, as an intermediate marker for potential adverse sequelae, might enable more precise estimates.

Screening strategies for tubal factor subfertility

BACKGROUND

Different screening strategies exist to estimate the risk of tubal factor subfertility, preceding laparoscopy. Three screening strategies, comprising Chlamydia trachomatis IgG antibody testing (CAT), high-sensitivity C-reactive protein (hs-CRP) testing and hysterosalpingography (HSG), were explored using laparoscopy as reference standard and the occurrence of a spontaneous pregnancy as a surrogate marker for the absence of tubal pathology.

METHODS

In this observational study, 642 subfertile women, who underwent tubal testing, participated. Data on serological testing, HSG, laparoscopy and interval conception were collected. Multiple imputations were used to compensate for missing data.

RESULTS

Strategy A (HSG) has limited value in estimating the risk of tubal pathology. Strategy B (CAT-->HSG) shows that CAT significantly discerns patients with a high versus low risk of tubal pathology, whereas HSG following CAT has no additional value. Strategy C (CAT-->hs-CRP-->HSG) demonstrates that hs-CRP may be valuable in CAT-positive patients only and HSG has no additional value.

CONCLUSIONS

CAT is proposed as first screening test for tubal factor subfertility. In CAT-negative women, HSG may be performed because of its high specificity and fertility-enhancing effect. In CAT-positive women, hs-CRP seems promising, whereas HSG has no additional value. The position and timing of laparoscopy deserves critical reappraisal.

Circulating antibodies to a conserved epitope of the Chlamydia trachomatis 60-kDa heat shock protein is associated with decreased spontaneous fertility rate in ectopic pregnant women treated by salpingectomy

PROBLEM

This prospective study was aimed to evaluate whether non-invasive clinical and serologic parameters of tubal disease are predictive for subsequent spontaneous conception and pregnancy outcome after first episode of ectopic pregnancy (EP).

METHOD OF STUDY

Overall, 144 women aged <35 years were enrolled. Outcome of subsequent spontaneous conception was analyzed after 3 years and compared with clinical parameters and antibody responses to Chlamydia trachomatis and epitopes of the 60-kDa chlamydial heat shock protein (CHSP-60).

RESULTS

Antibody response to a conserved epitope of CHSP-60 (amino acids, aa 260-277) was independently correlated with both decreased spontaneous conception and term delivery rates (adjusted odds ratios, OR: 3.6 and 5.4, respectively).

CONCLUSION

Presence of circulating antibodies to a conserved epitope of the CHSP-60 is associated with a lower spontaneous conception rate, and increased likelihood of adverse pregnancy outcome in women treated by salpingectomy for first episode of EP.

Chlamydia trachomatis-associated tubal factor subfertility: Immunogenetic aspects and serological screening

Chlamydia (C.) trachomatis female genital tract infections usually remain asymptomatic and untreated. Therefore, an adequate immune response, rather than antibiotic treatment, is essential to clear the pathogen. Most women will effectively clear C. trachomatis infections, but some will have persistent C. trachomatis infections, which may ascend to the upper genital tract and increase the risk of tubal factor subfertility. Pattern recognition receptors (PRRs) of the toll-like receptor (TLR) and nucleotide-binding oligomerization domain (NOD) families recognize C. trachomatis and initiate the immune response. Host immune factors are determinants of the course of C. trachomatis infections. Genetic variations in TLR and NOD genes may affect receptor function, leading to inadequate recognition of C. trachomatis, an inadequate immune response, and consequently an increased risk of persistence and late sequelae. For the risk assessment of tubal pathology in subfertile women, C. trachomatis immunoglobulin (Ig) G antibody testing (CAT) in serum is widely used. A positive CAT is indicative of a previous infection but not of a persistent infection. Measuring serological markers of persistence, of which C-reactive protein (CRP) seems promising, in CAT-positive women may identify a subgroup of subfertile women with persistent C. trachomatis infections and the highest risk of tubal pathology.