Longitudinal change in the serology of antibodies to Chlamydia trachomatis pgp3 in children residing in a trachoma area.

Abstract

A serologic test for antibodies to chlamydial antigen pgp3 may be a useful tool for trachoma surveillance. However, little is known about the stability of antibody status over time, or factors associated with seroreversion/conversion. A cohort of 2,111 children ages 1-9 years in Tanzania were followed for one year in the absence of mass azithromycin. At baseline and follow-up, they were evaluated for trachoma, chlamydial infection, and antibodies to chlamydial antigen pgp3. At baseline, 31% of children were seropositive for pgp3 antibodies and 6.4% seroreverted to negative over one year. Of those seronegative, 9.8% seroconverted over the year. The seroreverters had lower baseline mean fluorescence intensity (MFI-BG) values compared to the seropositives who remained positive (Odds Ratio = 0.04 for every unit increase in log10MFI-BG, 95% CI = 0.02-0.09), and were more likely to live in communities with trachoma <5% (p < 0.008). While seroconversion was expected, seroreversion was unexpected. The low seroprevalence rate reported from low endemic areas may be due to seroreversion as well as lack of exposure.

• Authors: Sheila K West, Beatriz Munoz, Hemjot Kaur, Laura Dize, Harran Mkocha, Charlotte A Gaydos, Thomas C Quinn
• Journal: Scientific reports (Sci Rep) Vol. 8 Issue 1 Pg. 3520 (02 23 2018) ISSN: 2045-2322 [Electronic] England
• PMID: 29476106 (Publication Type: Clinical Trial, Journal Article, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural)

Chemical References

• Antibodies, Bacterial
• Antigens, Bacterial
• Bacterial Proteins
• Immune Sera
• pgp3 protein, Chlamydia

Topics

• Antibodies, Bacterial (blood)
• Antigens, Bacterial (blood, immunology)
• Bacterial Proteins (blood, immunology)
• Child
• Child, Preschool
• Chlamydia trachomatis (growth & development, immunology, pathogenicity)
• Cohort Studies
• Female
• Humans
• Immune Sera (chemistry)
• Infant
• Male
• Seroconversion
• Seroepidemiologic Studies
• Tanzania (epidemiology)
• Trachoma (diagnosis, epidemiology, immunology, microbiology)