Monitoring transmission intensity of trachoma with serology

• DOI: 10.1101/2023.02.13.23285881
• Publication Date: 2023-02-16T20:35:12Z
• Authors: Christine Tedijanto; Anthony W. Solomon; Diana L. Martin; Scott D. Nash; Jeremy D. Keenan; Thomas M. Lietman; Patrick J. Lammie; Kristen Aiemjoy; Abdou Amza; Solomon Aragie; Ahmed M. Arzika; E. Kelly Callahan; Sydney Carolan; Adisu Abebe Dawed; E. Brook Goodhew; Sarah Gwyn; Jaouad Hammou; Boubacar Kadri; Khumbo Kalua; Ramatou Maliki; Beido Nassirou; Fikre Seife; Zerihun Tadesse; Sheila K. West; Dionna M. Wittberg; Taye Zeru; Benjamin F. Arnold
• Keywords: Physiology; Epidemiology; Seroprevalence; Chlamydia trachomatis; Vaginal Microbiome and Sexually Transmitted Infections; Engineering; 0302 clinical medicine; Seroepidemiologic Studies; Prevalence; Pathology; 2.2 Factors relating to the physical environment; Aetiology; Chlamydia; Child; Immunology and Microbiology; screening and diagnosis; Q; Bacterial; Life Sciences; Antibodies, Bacterial; 3. Good health; Detection; Infectious Diseases; Serology; Environmental health; Cytology Screening; Seroconversion; Child, Preschool; Medicine; Infection; Pediatric Research Initiative; Science; Human Papillomavirus and Cervical Cancer Epidemiology; Clinical Sciences; Immunology; Population; 610; Microbiology; Antibodies; Article; 03 medical and health sciences; Virology; 616; Health Sciences; Humans; Antigens; Preschool; Eye Disease and Disorders of Vision; Antibody; Trachoma; Antigens, Bacterial; Biomedical and Clinical Sciences; FOS: Clinical medicine; Infant; Biological Basis and Clinical Management of Syphilis; Transmission (telecommunications); 4.1 Discovery and preclinical testing of markers and technologies; Good Health and Well Being; FOS: Biological sciences; Electrical engineering; Subclinical infection

AbstractTrachoma, caused by ocularChlamydia trachomatisinfection, is targeted for global elimination as a public health problem by 2030. To provide evidence for use of antibodies to monitorC. trachomatistransmission, we collated IgG responses to Pgp3 antigen, PCR positivity, and clinical observations from 19,811 children aged 1– 9 years in 14 populations. We demonstrate that age-seroprevalence curves consistently shift along a gradient of transmission intensity: rising steeply in populations with high levels of infection and active trachoma and becoming flat in populations near elimination. Seroprevalence (range: 0–54%) and seroconversion rates (range: 0–15 per 100 person-years) correlate with PCR prevalence (r: 0.87, 95% CI: 0.57, 0.97). A seroprevalence threshold of 13.5% (seroconversion rate 2.75 per 100 person-years) identifies clusters with any PCR-identified infection at high sensitivity (>90%) and moderate specificity (69-75%). Antibody responses in young children provide a robust, generalizable approach to monitor population progress toward and beyond trachoma elimination.