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

Sheila K West, Beatriz Munoz, Hemjot Kaur, Laura Dize, Harran Mkocha, Charlotte A Gaydos, Thomas C Quinn

Research output: Contribution to journalArticle


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.

Original languageEnglish (US)
Article number3520
JournalScientific Reports
Issue number1
Publication statusPublished - Dec 1 2018


ASJC Scopus subject areas

  • General

Cite this