@article {1566, title = {Ongoing transmission of trachoma in low prevalence districts in Mozambique: results from four cross-sectional enhanced impact surveys, 2022.}, journal = {Sci Rep}, volume = {14}, year = {2024}, month = {2024 Oct 15}, pages = {22842}, abstract = {

Mozambique is making progress towards elimination of trachoma as a public health problem, but in some districts trachomatous inflammation-follicular (TF) prevalence remains above the 5\% elimination threshold despite years of various interventions, including antibiotic mass drug administration. To characterize transmission in four districts, we incorporated testing of ocular infection and serology into routine trachoma impact surveys (TIS) in August 2022. We examined residents aged >= 1 year for trachoma and collected information on household water, sanitation, and hygiene. Among children aged 1-9 years, we tested conjunctival swabs for Chlamydia trachomatis nucleic acid and dried blood spots for C. trachomatis antibodies. We modeled age-dependent seroprevalence to estimate seroconversion rate (SCR). We examined 4841 children aged 1-9 years. TF prevalence ranged between 1.1 and 6.0\% with three districts below the 5\% threshold. PCR-confirmed infection prevalence ranged between 1.1 and 4.8\%, and Pgp3 seroprevalence ranged between 8.8 and 24.3\%. Pgp3 SCR was 1.9 per 100 children per year in the district with the lowest TF prevalence. Two other districts with TF < 5\% had SCR of 5.0 and 4.7. The district with TF >= 5\% had a SCR of 6.0. This enhanced TIS furthered understanding of transmission in these districts and provides information on additional indicators for monitoring trachoma programs.

}, keywords = {Antibodies, Bacterial, Child, Child, Preschool, Chlamydia trachomatis, Cross-Sectional Studies, Female, Humans, Infant, Male, Mozambique, Prevalence, Seroepidemiologic Studies, Trachoma}, issn = {2045-2322}, doi = {10.1038/s41598-024-71201-z}, author = {Sitoe, Henis Mior and Oswald, William E and Zita, Felizmina and Fall, Mawo and Momade, Tamimo and Adams, Molly W and Flueckiger, Rebecca M and McPherson, Scott and Eyob, Sabrina and Doan, Thuy and Lietman, Thomas M and Arnold, Benjamin F and Wickens, Karana and Gwyn, Sarah and Martin, Diana L and Kasubi, Mabula and Boyd, Sarah and Bakhtiari, Ana and Jimenez, Cristina and Solomon, Anthony W and Harding-Esch, Emma M and Mwingira, Upendo J and Ngondi, Jeremiah M} } @article {1571, title = {Seroepidemiology of trachoma in a low prevalence region receiving annual mass azithromycin distribution in Maradi, Niger.}, journal = {PLoS Negl Trop Dis}, volume = {18}, year = {2024}, month = {2024 Dec 09}, pages = {e0012727}, abstract = {

BACKGROUND: Trachoma programs use the indicator trachomatous inflammation--follicular (TF) to monitor indication for and response to treatment for trachoma at the district level. Alternative indicators, including serologic markers, are increasingly being evaluated for trachoma surveillance. We evaluated seroprevalence of IgG antibodies to the Pgp3 antigen in two districts in Maradi, Niger thought to have low TF prevalence.

METHODS: Data were collected as part of the baseline assessment of the Azithromycin Reduction to Reach Elimination of Trachoma (ARRET) trial in September 2021. A random sample of 80 communities was selected from Mayahi and Guidan Roumdji districts, both of which had TF prevalence <20\% at their most recent trachoma impact survey in 2018. A random sample of 50 children per community was sampled. We collected field grades, conjunctival swabs for processing PCR for ocular Chlamydia trachomatis, and dried blood spots for serologic assessment.

RESULTS: Of 3,994 children sampled in 80 communities, 49\% were female and median age was 4 years. Overall TF prevalence was 4.6\% (95\% CI 3.5 to 5.8\%) and trachomatous inflammation-intense (TI) prevalence was 0.6\% (95\% 0.3 to 0.9\%). The prevalence of ocular chlamydia was 0.03\% (95\% CI 0.08\%). Seroprevalence for Pgp3 antibodies was 6.3\% (95\% CI 5.5 to 7.1\%) in 1-9-year-olds and 3.7\% (95\% CI 2.9 to 4.4\%) in 1-5-year-olds. TF and Pgp3 seroprevalence were better correlated in 1-5-year-olds (correlation coefficient 0.29) compared to 1-9-year-olds (correlation coefficient 0.09).

CONCLUSIONS: In this low trachoma prevalence setting in Niger, seroprevalence of antibodies to Pgp3 were consistent with little ongoing transmission of C. trachomatis.

}, issn = {1935-2735}, doi = {10.1371/journal.pntd.0012727}, author = {Amza, Abdou and Kadri, Boubacar and Nassirou, Beido and Arzika, Ahmed and Gebreegziabher, Elisabeth and Hu, Huiyu and Zhong, Lina and Chen, Cindi and Yu, Danny and Abraham, Thomas and Liu, YuHeng and Wickens, Karana and Doan, Thuy and Martin, Diana and Arnold, Benjamin F and Lietman, Thomas M and Oldenburg, Catherine E} }