What Can Serology Tell Us About the Burden of Infertility in Women Caused by Chlamydia?

Candidate antibody reference reagents for Chlamydia trachomatis serology

Chlamydia trachomatis (Ct) serology is an important tool for monitoring infection and disease burden but there are currently no formal reference reagents to harmonize results reporting. Our objective was to develop a panel of candidate reference reagents with reactivity against the major outer membrane protein (MOMP) and virulence factor (pgp3) antigens. Plasma packs from females (20-40 years old) were screened against MOMP and pgp3 antigens and selected positive and negative samples pooled to create a panel of candidate antibody reference reagents that were tested in two laboratories. Antigen specificity and internal quality assurance were also evaluated. Suitable candidate materials have been selected to produce Ct reference reagents.

Chlamydia trachomatis Seroassays Used in Epidemiologic Research: A Narrative Review and Practical Considerations

Chlamydia trachomatis (CT) is a sexually transmitted infection that can lead to adverse reproductive health outcomes. CT prevalence estimates are primarily derived from screening using nucleic acid amplification tests (NAATs). However, screening guidelines in the United States only include particular subpopulations, and NAATs only detect current infections. In contrast, seroassays identify past CT infections, which is important for understanding the public health impacts of CT, including pelvic inflammatory disease and tubal factor infertility. Older seroassays have been plagued by low sensitivity and specificity and have not been validated using a consistent reference measure, making it challenging to compare studies, define the epidemiology of CT, and determine the effectiveness of control programs. Newer seroassays have better performance characteristics. This narrative review summarizes the "state of the science" for CT seroassays that have been applied in epidemiologic studies and provides practical considerations for interpreting the literature and employing seroassays in future research.

Intact Transition Epitope Mapping—Serological Inspection by Epitope EXtraction (ITEM—SIX)

Precision medicine requests accurate serological inspections to precisely stratify patients for targeted treatment. Intact transition epitope mapping analysis proved surrogate seroconversion of a model organism’s serum when spiked with a monoclonal murine anti-Ovalbumin antibody (mAb) with epitope resolution. Isolation of the IgG fraction from blood serum applied two consecutive protein precipitation steps followed by ultrafiltration and resulted in an ESI-MS analysis-ready IgG preparation. For epitope mapping by epitope extraction, the Ovalbumin antigen was digested with trypsin. After desalting, the peptide mixture was added to the ESI-MS-ready IgG preparation from mAb-spiked serum and the solution was incubated to form an immune complex between the Ovalbumin-derived epitope peptide and the anti-Ovalbumin mAb. Then, the entire mixture of proteins and peptides was directly electrosprayed. Sorting of ions in the mass spectrometer’s gas phase, dissociation of the immune complex ions by collision-induced dissociation, and recording of the epitope peptide ion that had been released from the immune complex proved the presence of the anti-Ovalbumin mAb in serum. Mass determination of the complex-released epitope peptide ion with isotope resolution is highly accurate, guaranteeing high specificity of this novel analysis approach, which is termed Intact Transition Epitope Mapping—Serological Inspections by Epitope EXtraction (ITEM—SIX).

Mpox (Monkeypox) Presenting as Cervical and Vulvar Disease

BACKGROUND

Since the beginning of the current mpox (formerly "monkeypox") outbreak in May 2022, 23,465 confirmed cases of monkeypox virus infection have been reported in Europe; women represent less than 1% of these cases. Mpox lesions are found with greater frequency in the genital area, and, in women, have been described primarily in the vulva.

CASE

We present a case of monkeypox virus infection in a 28-year-old woman confirmed by polymerase chain reaction testing, in which the only clinical manifestation was the appearance of concomitant lesions in the cervix and the vulva, with no other clinical features. No other sexual transmitted diseases were found. The lesions disappeared spontaneously in 2 weeks.

CONCLUSION

Mpox lesions can affect the cervix; thus, recognition by gynecologists is important. Given the current epidemic outbreak, correct identification is essential to help control disease transmission.

What Do Diagnoses of Pelvic Inflammatory Disease in Specialist Sexual Health Services in England Tell Us About Chlamydia Control?

BACKGROUND

Pelvic inflammatory disease (PID) is an outcome measure for the evaluation of chlamydia screening programs. We explore PID diagnoses in specialist sexual health services (SSHSs) in England to inform the evaluation of the National Chlamydia Screening Programme, which was implemented nationally in 2008.

METHODS

We conducted descriptive analyses using data on diagnoses of PID-with and without Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (GC)-by age and year of birth, in SSHSs between 2009 and 2019 from the GUMCAD STI Surveillance System database. Rates were calculated per 100 000 females residing in England.

RESULTS

CT screening activity peaked in 2010. The rates of all PID diagnoses decreased between 2009 and 2019 by 39%. CT-associated PID (CT-PID) declined by 58%, and nonspecific PID declined by 37%. GC-PID increased by 34%. CT-PID decreased across all age groups with the highest observed decline, 71%, in 15- to 19-year-olds. A dose-response relationship was observed between CT-PID rates and screening, with rates lowest in those with the greatest exposure to screening.

CONCLUSIONS

There was a marked decline in diagnoses of CT-PID, and nonspecific PID, at SSHSs after the introduction of widespread chlamydia screening, whereas GC-PID diagnoses increased. This ecological trend was broadly consistent with what we would have expected to see if widespread screening reduced the incidence of chlamydia-associated PID (and of nonspecific PID), as has been observed in randomized controlled trials of screening.