Risk factors for active trachoma and Chlamydia trachomatis infection in rural Ethiopia after mass treatment with azithromycin.
OBJECTIVE
To investigate risk factors for ocular Chlamydia trachomatis infection and active trachoma, comparing communities receiving or not receiving an intervention programme of community-wide azithromycin treatment and health education.


METHODS
In a 3-year post-intervention follow-up survey, 1722 children aged 3-9 years, from randomly selected households in 37 communities, were examined for signs of active trachoma and had samples taken to test for ocular C. trachomatis by polymerase chain reaction. Multivariate random effects logistic regression analyses considered interventions at community level, adjusting for other independent risk factors as appropriate.


RESULTS
Younger age, ocular discharge and flies on eyes were risk factors for active trachoma in communities with and without antibiotic treatment. After azithromycin treatment, odds of active trachoma were lower in children aged 6-9 years than in children aged 3-5 years (OR 0.48, 95% CI: 0.36-0.66) and higher for children with ocular discharge (OR 4.5, 95% CI: 2.6-7.7) or flies on their eyes (OR 2.5, 95% CI: 1.6-3.7). Odds of C. trachomatis infection were lower in children aged 6-9 years than in younger children (OR 0.47, 95% CI: 0.23-0.96); and in children who received 2 or 3 doses rather than 1 (OR 0.26, 95% CI: 0.08-0.88).


CONCLUSIONS
In communities that received or did not receive the mass antibiotic treatment, the same risk factors for C. trachomatis and active trachoma were identified. Education and environmental improvements need to supplement antibiotic campaigns in order to positively impact on these remaining child level risk factors.
Edwards
Tansy
T
London School of Hygiene and Tropical Medicine, London, UK. tansy.edwards@lshtm.ac.uk
Harding-Esch
Emma M
EM
Hailu
Girum
G
Andreason
Aura
A
Mabey
David C
DC
Todd
Jim
J
Cumberland
Phillippa
P
D000367:Age Factors; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D017963:Azithromycin / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D002690:Chlamydia Infections / Q000453:epidemiology / Q000517:prevention & control; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D004175:Diptera; D019353:Endemic Diseases / Q000517:prevention & control; D005002:Ethiopia; D006266:Health Education; D006801:Humans; D006920:Hygiene; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D012423:Rural Health; D014141:Trachoma / Q000453:epidemiology* / Q000517:prevention & control
D000900:Anti-Bacterial Agents; D017963:Azithromycin