Progression of scarring trachoma in Tanzanian children: A four-year cohort study

• Published in: PLoS neglected tropical diseases 2019-08, Vol.13 (8), p.e0007638-e0007638
• Main Authors: Ramadhani, Athumani M, Derrick, Tamsyn, Macleod, David, Massae, Patrick, Mafuru, Elias, Malisa, Aiweda, Mbuya, Kelvin, Roberts, Chrissy H, Makupa, William, Mtuy, Tara, Bailey, Robin L, Mabey, David C W, Holland, Martin J, Burton, Matthew J
• Format: Article
• Language: English
• Subjects: Antibiotics; Bacteria; Bacterial infections; Biology and Life Sciences; Child; Child development; Children; Chlamydia; Chlamydia infections; Chlamydia trachomatis; Chlamydia trachomatis - isolation & purification; Chlamydia trachomatis - pathogenicity; Cicatrix - epidemiology; Cohort analysis; Cohort Studies; Cohorts; Complications; Conjunctiva; Conjunctiva - diagnostic imaging; Control programs; Correlation analysis; Demographic aspects; Detection; Development and progression; Disease Progression; Female; Genomes; Humans; Hygiene; Incidence; Infection; Infections; Inflammation; Longitudinal Studies; Male; Medical research; Medicine; Medicine and Health Sciences; Odds Ratio; Pediatric diseases; People and Places; Research and Analysis Methods; Risk Factors; Scars; Sexually transmitted diseases; STD; Studies; Supervision; Surgery; Tanzania - epidemiology; Trachoma; Trachoma - epidemiology; Tropical diseases; Tumor necrosis factor-TNF
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0007638

Trachoma is a progressive blinding disease initiated by infection of the conjunctiva with Chlamydia trachomatis. Repeated infections are thought to cause chronic inflammation, which drives scarring, leading to in-turning of the eyelids. The relationship between C. trachomatis, clinical inflammation and scarring development in children is not fully understood due to a paucity of longitudinal studies with infection data at frequent follow-up. This longitudinal cohort study took place in northern Tanzania. Children aged 6-10 years at baseline were eligible for inclusion. Participants were visited every three months for four years. Clinical signs and conjunctival swabs for C. trachomatis detection by qPCR were collected at each time-point. Conjunctival photographs from baseline and final time-points were graded and compared side-by-side to determine scarring incidence and progression. Of the 666 children enrolled in the study, outcome data were obtained for 448. Scarring progression was detected in 103/448 (23%) children; 48 (11%) of which had incident scarring and 55 (12%) had progression of existing scarring. Scarring was strongly associated with increasing episodes of trachomatous papillary inflammation (TP). Weaker associations were found between episodes of C. trachomatis infection and follicular trachoma (TF) with scarring progression in unadjusted models, which were absent in multivariable analysis after adjusting for inflammation (multivariable results: C. trachomatis p = 0.44, TF p = 0.25, TP p =