Changes in trachoma indicators in Kiribati with two rounds of azithromycin mass drug administration, measured in serial population-based surveys

• Published in: PLoS neglected tropical diseases Vol. 17; no. 7; p. e0011441
• Main Authors: Goodhew, E Brook, Taoaba, Raebwebwe, Harding-Esch, Emma M, Gwyn, Sarah E, Bakhtiari, Ana, Butcher, Robert, Cama, Anasaini, Guagliardo, Sarah Anne J, Jimenez, Cristina, Mpyet, Caleb D, Tun, Kab, Wickens, Karana, Solomon, Anthony W, Martin, Diana L, Tekeraoi, Rabebe
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07.07.2023; Public Library of Science (PLoS)
• Subjects: Antibodies; Antigens; Azithromycin; Biology and Life Sciences; Disease control; Dosage and administration; Drinking water; Drug therapy; Drugs; Earth Sciences; Ethics; Evaluation; Eye examinations; Health aspects; Households; Indicators; Infections; Infectious Diseases; Medical laboratories; Medicine and Health Sciences; Nucleotide sequence; Parasitology; Patient outcomes; People and Places; Polls & surveys; Polyvinyl alcohol; Prevalence studies (Epidemiology); Public health; Research and Analysis Methods; Seroconversion; Serology; Surveys; Tetracycline; Tetracyclines; Towns; Trachoma; Tropical diseases; Tropical Medicine; Viral antibodies; Kiribati; Atlanta Georgia; United States > US
• DOI: 10.1371/journal.pntd.0011441
• ISSN: 1935-2735; 1935-2727

Baseline mapping in the two major population centers of Kiribati showed that trachoma was a public health problem in need of programmatic interventions. After conducting two annual rounds of antibiotic mass drug administration (MDA), Kiribati undertook trachoma impact surveys in 2019, using standardized two-stage cluster surveys in the evaluation units of Kiritimati Island and Tarawa. In Kiritimati, 516 households were visited and in Tarawa, 772 households were visited. Nearly all households had a drinking water source and access to an improved latrine. The prevalence of trachomatous trichiasis remained above the elimination threshold (0.2% in ≥15-year-olds) and was virtually unchanged from baseline. The prevalence of trachomatous inflammation-follicular (TF) in 1-9-year-olds decreased by approximately 40% from baseline in both evaluation units but remained above the 5% TF prevalence threshold for stopping MDA. TF prevalence at impact survey was 11.5% in Kiritimati and 17.9% in Tarawa. Infection prevalence in 1-9-year-olds by PCR was 0.96% in Kiritimati and 3.3% in Tarawa. Using a multiplex bead assay to measure antibodies to the C. trachomatis antigen Pgp3, seroprevalence in 1-9-year-olds was 30.2% in Kiritimati and 31.4% in Tarawa. The seroconversion rate, in seroconversion events/100 children/year, was 9.0 in Kiritimati and 9.2 in Tarawa. Seroprevalence and seroconversion rates were both assessed by four different assays, with strong agreement between tests. These results show that, despite decreases in indicators associated with infection at impact survey, trachoma remains a public health problem in Kiribati, and provide additional information about changes in serological indicators after MDA.